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Aim Method Results Conclusion Clinical Trial Registration Number The aim of this study was to compare the clinicopathological and oncological characteristics of sporadic colorectal cancer (CRC) between young and elderly patients without any genetic mutations that cause hereditary CRC.In this cross‐sectional, retrospective study conducted at three tertiary referral hospitals, we enrolled 1599 patients with CRC who underwent surgery between January 2010 and December 2017, including 157 young patients (age ≤ 40 years; yCRC) and 1442 elderly patients (age ≥ 70 years; eCRC). The clinicopathological and oncological outcomes were compared between the two groups.The median age at diagnosis was 37 years in the yCRC group (range 33.0–39.2 years) and 76 years in the eCRC group (range 72.0–79.0 years). The yCRC group did not present with advanced stages at diagnosis compared with the eCRC group, and the distribution of tumour stages was similar between the two groups. Microsatellite instability (MSI) testing revealed no difference in the frequency of tumours with high MSI (7.8% in yCRC, 5.8% in eCRC), and the frequency of mutations in the KRAS, NRAS and BRAF genes was also similar. The 3‐year overall survival was better in the yCRC group than in the eCRC group (97.4% vs. 83.5%, p < 0.001); however, no such difference was observed in cancer‐specific survival.Genetically proven sporadic CRCs did not differ significantly between young and elderly patients in terms of tumour stage, tumour location and various molecular features.The study was retrospectively registered with Clinical Trials.gov (no. NCT05601609). [ABSTRACT FROM AUTHOR]

Background: Portomesenteric venous thrombosis (PMVT) can occur after colorectal surgery. Most previous studies included patients with various diseases, especially inflammatory bowel disease. The prevalence and clinical significance of PMVT developing after surgery for colorectal cancer (CRC) remain unclear.Methods: Consecutive patients who underwent resection for CRC between June 2003 and April 2016 were retrospectively analyzed. Postoperative PMVT was diagnosed based on pre- and postoperative computed tomography (CT).Results: Postoperative PMVT developed in 10 (0.24%) of 4232 patients who underwent resection for CRC. One patient had alcoholic liver cirrhosis, whereas nine did not have prior or current liver disease. PMVT in eight patients was detected within 2 weeks after surgery by CT, performed to evaluate non-specific symptoms such as mild fever and abdominal pain, or performed postoperatively after deep pelvic dissection. PMVT in the remaining two asymptomatic patients was diagnosed following surveillance CT 3 and 7 months after surgery, respectively. PMVT in the patient with liver cirrhosis was detected 13 days after surgery and found to involve the main portal vein, causing hyperbilirubinemia and requiring emergency thrombectomy with thrombolysis. PMVT in the nine patients without liver disease was resolved by anticoagulation therapy or conservative care without long-term complications.Conclusion: PMVT after CRC surgery is likely an early postoperative event in most patients. The incidence of clinically significant PMVT in patients with CRC may be lower than previously reported. CT was reliable in the diagnosis and follow-up of these patients. Most patients with PMVT can be managed conservatively without serious long-term morbidity. [ABSTRACT FROM AUTHOR]

Purpose: Recently, several reports have suggested that tumor location serves as a prognostic biomarker in advanced colorectal cancer. However, the prognostic implication of tumor location in patients with early-stage colorectal cancer remains unclear. This study was aimed to examine the prognostic implication of tumor location in patients with early-stage colorectal cancer.Methods: Patients with stage I and low-risk stage II colorectal cancer, treated with radical surgery in a hospital setting between May 2003 and September 2014, were retrospectively reviewed. Patients who underwent (neo) adjuvant chemotherapy and/or radiotherapy and whose microsatellite instability (MSI) status was lacked were excluded. Distal colon cancer was defined as tumors located from the splenic flexure colon to the sigmoid colon.Results: A total of 712 patients were included in this study. Of these patients, 23 (3.2%) had a recurrence at a median follow-up time of 46 months. The tumor recurrence rate was significantly low in patients with proximal colon cancer. In the multivariate analysis, tumors located in the distal colon or rectum (distal colon, hazard ratio [HR] 9.213, P = 0.035; rectum, HR 15.366, P = 0.009) and T3 tumors (HR 4.590, P = 0.017) were related to tumor recurrence. A higher prevalence of tumor recurrence was found in patients with two recurrence factors than those who had only one factor or none (P < 0.001).Conclusions: Tumor location, as well as T stage, had prognostic implication in patients with early-stage colorectal cancer. Validation of our results is needed in a large cohort with genetic characterization. [ABSTRACT FROM AUTHOR]

Purpose: Desmoid tumor (DT) is a rare myofibroblastic proliferative neoplasm, but can occur in up to 26% of patients with familial adenomatous polyposis (FAP). Therefore, DT may be an extraintestinal manifestation of FAP that precedes the development of advanced malignancies. The aim of this study was to identify the incidence of polyps in DT patients and investigate value of colonoscopy for diagnosis of FAP in DT patients without gastrointestinal symptoms. Materials and methods: The records of patients diagnosed with DT were retrospectively reviewed using the clinical data warehouse (CDW) system. Clinical data, including location of tumor, type(s) of treatment, and colonoscopic findings, were collected. Results: Sixty-five patients were diagnosed with DT during the study period; 10 patients received colonoscopies before diagnosis of DT, and 20 patients received colonoscopies after diagnosis of DT. The mean age at diagnosis of DT was 41.9 ± 16.7 years old (range 17-74). Most tumors were extra-abdominal ( n = 24, 80.0%), and fewer were intra-abdominal ( n = 4, 13.3%) or in an abdominal wall ( n = 2, 6.7%). The colonoscopy results revealed one or two tubular adenomas in 11 patients (36.6%), although none of the patients had colorectal polyposis or colorectal cancer. Conclusion: None of the patients in our study population had colorectal polyposis. Routine colonoscopy of DT patients without gastrointestinal symptoms seems to have low diagnostic yield for detection of FAP. [ABSTRACT FROM AUTHOR]

Objective: AT-rich interactive domain 1A (ARID1A) has recently been identified as a novel tumor suppressor in various tumor types. This study was designed to explore the clinical relevance and prognostic impact of ARID1A expression loss in colorectal cancer (CRC) and gastric cancer (GC). Methods: Immunohistochemistry for ARID1A was performed using tissue microarray blocks containing 196 CRCs and 275 GCs, along with paired normal mucosa. Data on clinicopathologic variables and oncologic outcomes of patients were collected and analyzed. Results: We identified 6.1% (12/196) CRC and 8.0% (22/275) GC cases showing loss of ARID1A expression. Expression of ARID1A in paired mucosal epithelial cells was normal in all patients. Loss of ARID1A expression was significantly correlated with negative lymphatic invasion (p = 0.003) in CRC, with large tumor size (p = 0.037) in GC, and with expanding tumor border in both tumor types (CRC, p = 0.010; GC, p = 0.031). However, no association was evident between ARID1A expression and 5-year overall survival in both tumor types. Conclusions: Loss of ARID1A expression is uncommon and not associated with oncologic outcome but may be related to less invasive clinicopathologic features in CRC and GC. Further studies with a larger number of subjects are needed to establish the possible prognostic impact of ARID1A expression loss. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Aim: This study investigated the association between preoperative and postoperative changes in skeletal muscle mass and long‐term oncological outcomes in patients with non‐metastatic colorectal cancer. Method: Patients who underwent surgery for Stages I–III colorectal cancer from January 2014 to December 2015 were included. Skeletal muscle mass was evaluated through preoperative and postoperative abdominopelvic CT scans. A multivariable analysis was conducted to determine the factors affecting disease‐free survival rates. Results: A total of 238 patients were analysed. Forty‐nine (25.9%) patients had preoperative sarcopenia. Patients with preoperative sarcopenia showed lower 3‐year disease‐free survival (58.5% vs. 78.4%, P = 0.001). Patients with postoperative sarcopenia also showed significantly lower 3‐year disease‐free survival compared to postoperative patients without sarcopenia at 6, 12 and 18 months, respectively (53.9% vs. 77.8%; 69.7% vs. 81.8%; 69.1% vs. 87.7%, P = 0.004). In a subgroup analysis, patients with both preoperative and postoperative sarcopenia showed the lowest 3‐year disease‐free survival rates (50.9%). The incidence of tumour recurrence was higher among the patients who had lost more skeletal muscle mass at 12, 18 and 24 months (−14.3 cm2/m2 vs. −1.5 cm2/m2, P < 0.001; −24.5 cm2/m2 vs. −1.1 cm2/m2, P < 0.001; and −31.6 cm2/m2 vs. −1.4 cm2/m2, P < 0.001, respectively). A multivariable analysis demonstrated that the factors associated with disease‐free survival included tumour stage, venous invasion, adjuvant chemotherapy, and preoperative or postoperative sarcopenia. Conclusion: Not only preoperative but also postoperative sarcopenic changes adversely affect oncological outcomes following curative resection of colorectal cancer. Careful attention should be given to correcting sarcopenic status from the preoperative to the postoperative period. [ABSTRACT FROM AUTHOR]

Abstract: Background: The present study was conducted to assess the efficacy and safety of the delivery of radiofrequency energy to the anal canal (the SECCA procedure). Methods: Eight patients with fecal incontinence underwent the SECCA procedure. The Fecal Incontinence Severity Index (FISI) score and the Fecal Incontinence-related Quality of Life (FIQL) scale were completed at baseline and after the procedure. Anorectal manometry and endoanal ultrasound also were conducted. Results: Seven of the 8 patients were women, and the median age of the patients was 59 years (range, 28–73 y). The mean FISI score and all of the parameters in the FIQL scale with the exception of the embarrassment scale measured at 6 months after the procedure was not improved significantly. We observed no changes in the anal manometry and endoanal ultrasound parameters. Complications associated with the procedure developed in 7 of the 8 patients, including anal bleeding, anal pain, and anal mucosal discharge. Conclusions: The FISI score and FIQL scale were not improved significantly after the SECCA procedure, and considerable complications were associated with the procedure. [Copyright &y& Elsevier]

Degos' disease, otherwise known as 'malignant atrophic papulosis,' is a rare condition characterized by typical cutaneous lesions. Its involvement of the gastrointestinal (GI) tract is usually associated with a poor prognosis. We report a case of Degos' disease with GI involvement, which ultimately caused peritonitis, sepsis, and death, despite all treatment measures. A 59-yearold woman was admitted to our hospital with acute generalized abdominal pain. The patient had presented initially with multiple skin lesions 2 years earlier, and even with surgery for small-bowel perforation 10 months before this admission, Degos' disease had not been diagnosed. Explorative laparotomy revealed multifocal, ischemic changes in the small bowel with perforation in the mid-jejunum. After the operation, she suffered recurrent small-bowel fistulas and died within 3 months. In a patient with acute abdominal pain and typical atrophic papules, clinicians should retain a high index of suspicion for Degos' disease with GI involvement, even though it is rare. [ABSTRACT FROM AUTHOR]

Background: Acute postoperative pain is a common complication of inguinal hernia repair. Pain management using local application of anesthetic agents over the skin surrounding the surgical incision may reduce the requirement for other pain medications. Targeted topical analgesics such as 5% lidocaine patches have been known to improve acute and chronic pain. However, the clinical effect of lidocaine patches on postoperative pain after inguinal hernia repair has not been studied, especially in patients undergoing surgery at day surgery units.Methods/design: This is a single-center, prospective, double-blind, randomized, controlled clinical trial. Participants with unilateral inguinal hernia will be randomized to the lidocaine patch group or the placebo patch group. Based on the randomized allocation sequence, either lidocaine patches or placebo patches will be attached near each participant's surgical wound after open hernia repair under general anesthesia. Participants will be asked to follow up at our outpatient clinic on the first postoperative day and at 1 week after surgery. The primary outcome is pain intensity, which will be measured using the visual analog scale (VAS) at the time of discharge from the day surgery unit. The secondary outcomes are VAS score at 24 h and 1 week after surgery. We will collect and analyze the participants' clinical data (amount of intraoperative opioid use, time to recovery, and pain intensity at 30 min after surgery) and demographic characteristics (age, sex, body weight, and height).Discussion: This trial may not only provide evidence on the efficacy of a 5% lidocaine patch for acute postoperative pain management after unilateral inguinal hernia repair, but also demonstrate the efficacy and safety of the patch for post-discharge pain management.Trial Registration: ClinicalTrials.gov NCT04754451. Registered on February 10, 2021. [ABSTRACT FROM AUTHOR]

Purpose: To examine the ability of generative artificial intelligence (GAI) to answer patients' questions regarding colorectal cancer (CRC). Methods: Ten clinically relevant questions about CRC were selected from top-rated hospitals' websites and patient surveys and presented to three GAI tools (Chatbot Generative Pre-Trained Transformer [GPT-4], Google Bard, and CLOVA X). Their responses were compared with answers from the CRC information book. Response evaluation was performed by two groups, each consisting of five healthcare professionals (HCP) and patients. Each question was scored on a 1–5 Likert scale based on four evaluation criteria (maximum score, 20 points/question). Results: In an analysis including only HCPs, the information book scored 11.8 ± 1.2, GPT-4 scored 13.5 ± 1.1, Google Bard scored 11.5 ± 0.7, and CLOVA X scored 12.2 ± 1.4 (P = 0.001). The score of GPT-4 was significantly higher than those of the information book (P = 0.020) and Google Bard (P = 0.001). In an analysis including only patients, the information book scored 14.1 ± 1.4, GPT-4 scored 15.2 ± 1.8, Google Bard scored 15.5 ± 1.8, and CLOVA X scored 14.4 ± 1.8, without significant differences (P = 0.234). When both groups of evaluators were included, the information book scored 13.0 ± 0.9, GPT-4 scored 14.4 ± 1.2, Google Bard scored 13.5 ± 1.0, and CLOVA X scored 13.3 ± 1.5 (P = 0.070). Conclusion: The three GAIs demonstrated similar or better communicative competence than the information book regarding questions related to CRC surgery in Korean. If high-quality medical information provided by GAI is supervised properly by HCPs and published as an information book, it could be helpful for patients to obtain accurate information and make informed decisions. [ABSTRACT FROM AUTHOR]

Background: Preoperative (chemo)radiotherapy has been widely used as an effective treatment for locally advanced rectal cancer (LARC), leading to a significant reduction in pelvic recurrence rates. Because early administration of intensive chemotherapy for LARC has more advantages than adjuvant chemotherapy, total neoadjuvant therapy (TNT) has been introduced and evaluated to determine whether it can improve tumor response or treatment outcomes. This study aims to investigate whether short-course radiotherapy (SCRT) followed by intensive chemotherapy improves oncologic outcomes compared with traditional preoperative long-course chemoradiotherapy (CRT). Methods: A multicenter randomized phase II trial involving 364 patients with LARC (cT3–4, cN+, or presence of extramural vascular invasion) will be conducted. Patients will be randomly assigned to the experimental or control arm at a ratio of 1:1. Participants in the experimental arm will receive SCRT (25 Gy in 5 fractions, daily) followed by four cycles of FOLFOX (oxaliplatin, 5-fluorouracil, and folinic acid) as a neoadjuvant treatment, and those in the control arm will receive conventional radiotherapy (45–50.4 Gy in 25–28 fractions, 5 times a week) concurrently with capecitabine or 5-fluorouracil. As a mandatory surgical procedure, total mesorectal excision will be performed 2–5 weeks from the last cycle of chemotherapy in the experimental arm and 6–8 weeks after the last day of radiotherapy in the control arm. The primary endpoint is 3-year disease-free survival, and the secondary endpoints are tumor response, overall survival, toxicities, quality of life, and cost-effectiveness. Discussion: This is the first Korean randomized controlled study comparing SCRT-based TNT with traditional preoperative LC-CRT for LARC. The involvement of experienced colorectal surgeons ensures high-quality surgical resection. SCRT followed by FOLFOX chemotherapy is expected to improve disease-free survival compared with CRT, with potential advantages in tumor response, quality of life, and cost-effectiveness. Trial registration: This trial is registered at Clinical Research Information under the identifier Service KCT0004874 on April 02, 2020, and at Clinicaltrial.gov under the identifier NCT05673772 on January 06, 2023. [ABSTRACT FROM AUTHOR]

Background: Self-expanding metallic stenting (SEMS) is usual for the temporary resolution of obstructive left-sided colorectal cancer (CRC) as a bridge to elective surgery. However, there is no consensus regarding adequate time intervals from stenting to radical surgery. The aim of this study was to identify the optimal time interval that results in favorable short- and long-term outcomes. Methods: Data on patients with obstructive left-sided CRC who underwent elective radical surgery after clinically successful SEMS deployment in five tertiary referral hospitals from 2004 to 2016 were analyzed, retrospectively. An inverse probability treatment-weighted propensity score analysis was used to minimize bias. Postoperative short- and long-term outcomes were compared between two groups: an early surgery (within 8 days) group and delayed surgery (after 8 days) group. Results: Of 311 patients, 148 (47.6%) underwent early and 163 (52.4%) underwent delayed surgery. The median surgery interval was 9.0 days. After adjustment, the groups had similar patient and tumor characteristics. In terms of short-term outcomes, there was no difference in hospitalization length or postoperative complications. No deaths were observed. With a median follow-up of 71.0 months, no significant difference was observed between the groups in 5-year overall survival (early vs. delayed surgery: 79.6% vs. 71.3%, P = 0.370) and 5-year disease-free survival (early vs. delayed surgery: 59.1% vs. 60.4%, P = 0.970). Conclusions: In obstructive left-sided CRC, the time interval between SEMS and radical surgery did not significantly influence short- and long-term outcomes. Therefore, early surgery after SEMS could be suggested if there is no reason to postpone surgery for preoperative medical optimization. [ABSTRACT FROM AUTHOR]

This article discusses the modified laparoscopic Sugarbaker technique for repairing parastomal hernias using overlapping composite meshes. Parastomal hernias are common complications in patients with stomas, and surgical repair can be challenging due to high recurrence and complication rates. The Sugarbaker technique, which involves using overlapping composite meshes, has a lower recurrence rate and is currently preferred for PSH repair. The article provides a video demonstration of the technique and reports a successful case study of a 76-year-old female patient who did not experience any complications or recurrence of the hernia after the surgery. The authors conclude that laparoscopic PSH repair using overlapping meshes is feasible, safe, and effective in reducing hernia recurrence. [Extracted from the article]

Purpose: There has been no comparative study on the clinical value of magnetic resonance tumor regression grade (mrTRG)1–2 and ycT0–1N0 for the prediction of ypT0–1N0 after concurrent chemoradiotherapy (CCRT) for rectal cancer. We compared the diagnostic performance between mrTRG1–2 and ycT0–1N0 for predicting ypT0–1N0 as a selection criterion for non-radical management after CCRT in locally advanced rectal cancer. Methods: This retrospective study enrolled 291 patients from three referral hospitals between January 2018 and March 2020. The diagnostic performance of ycT0–1N0 and mrTRG1–2 for the prediction of ypT0–1N0 was compared in terms of sensitivity, specificity, positive-predictive value, negative-predictive value, and area under the curve (AUC). Results: Sixty-eight patients (23.4%) achieved ypT0–1N0. Nineteen patients (6.5%) had ycT0–1N0, and 91 patients (31.2%) had mrTRG1–2. For predicting ypT0–1N0, ycT0–1N0 had a sensitivity of 16.2% (95% confidence interval [CI]: 8.36‒27.10) and positive-predictive value of 57.9% (95% CI: 36.57‒76.63), while mrTRG1–2 had a sensitivity of 58.8% (95% CI: 46.23‒70.63) and positive-predictive value of 44.0% (95% CI: 36.46‒51.74). When predicting ypT0–1N0, mrTRG1–2 showed a higher AUC (0.680, 95% CI: 0.604‒0.756) than ycT0–1N0 (0.563, 95% CI: 0.481‒0.645) (P < 0.001). Conclusion: mrTRG1–2 might be a better indicator than ycT0–1N0 for the selection of non-radical management of advanced rectal cancer post-CCRT. However, additional diagnostic tools are required for predicting ypT0–1N0 because mrTRG1–2 or yc stage on MRI has insufficient evidence for diagnosing ypT0–1N0. [ABSTRACT FROM AUTHOR]

We aimed to compare the short- and long-term outcomes of simultaneous laparoscopic, hybrid, and open resection for colorectal cancer and synchronous liver metastases. We retrospectively analyzed the data of 647 patients with simultaneous resection of colorectal cancer and liver metastases between January 2006 and December 2018 at three tertiary referral hospitals. Patient's baseline characteristics, perioperative outcomes, pathological examination results, liver-specific recurrence rate and survivals were compared between the propensity score-matched groups. Forty-two and 81 patients were selected for the laparoscopic vs. hybrid groups, and 48 and 136 patients for laparoscopic vs. open groups, respectively. The laparoscopic group had fewer wound complications (2.1 vs. 13.2%; p = 0.028) than the open group, and a shorter postoperative hospital stay than the hybrid and open groups (8 vs. 11 days, p < 0.001 for both). The 5-year liver-specific recurrence rates were 38.7% and 46.0% in the laparoscopic and hybrid groups, respectively (p = 0.270), and 34.0% and 37.0% in the laparoscopic and open groups, respectively (p = 0.391). Simultaneous laparoscopic resection for colorectal cancer and liver metastases can be performed safely with significantly enhanced postoperative recovery and comparable long-term outcomes compared to hybrid and open resection. [ABSTRACT FROM AUTHOR]

Background and Aims: The feasibility of incidental cholecystectomy during colorectal cancer (CRC) surgery has not been determined as yet. We aimed to investigate the feasibility of incidental cholecystectomy during CRC surgery. Methods: The clinicopathologic data of patients who underwent CRC surgery between January 2004 and May 2011 were assessed. Patients with asymptomatic cholelithiasis were divided into groups that did and did not undergo incidental cholecystectomy. Their in-hospital morbidity and long-term biliary complications were compared. Results: Of the 282 patients identified, 143 (50.7%) underwent incidental cholecystectomy and 139 (49.3%) were observed without cholecystectomy. The two groups were similar in clinical characteristics, except for gender and operation time. Only one patient (0.7%) in the cholecystectomy group experienced an intraoperative biliary complication. There was no significant difference in overall in-hospital morbidity between the two groups. After a median follow-up period of 33 months, long-term biliary complications developed in 12 patients (8.6%) in the observation group, with 9 undergoing cholecystectomy. Conclusions: Incidental cholecystectomy was not associated with increased postoperative morbidity, whereas previously asymptomatic patients were at substantial long-term risk of becoming symptomatic. Thus, in the absence of clear contraindications, concomitant cholecystectomy might be a desirable treatment option during CRC surgery in patients with asymptomatic gallstones. © 2015 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: Although several risk factors for acute urinary retention after rectal cancer surgery have been proposed, few studies have enrolled a homogeneous group of patients without preoperative urinary dysfunction. We aimed to identify risk factors and preventive measures for acute urinary retention after rectal cancer surgery. Methods: This study was a retrospective review of prospectively collected data from included patients who underwent rectal cancer surgery at a single center. Preoperative urinary function was evaluated using the International Prostate Symptom Score (IPSS). Clinical data were collected prospectively and analyzed to assess the risk factors for acute urinary retention, which was defined as the inability to self-void after removing the urinary catheter requiring catheterization or reinsertion of an indwelling catheter. Results: Of 352 patients with mild preoperative IPSS (0-7), 48 (13.6 %) experienced acute urinary retention. Multivariate logistic regression analysis showed that male sex (odds ratio [OR] 2.240, p = 0.039), laparoscopic operation (OR 2.421, p = 0.024), intraoperative intravenous fluid ≥2,000 mL (OR 3.794, p < 0.001), and urinary catheter removal on postoperative day 1 or 2 (OR 3.650, p = 0.017) were independent risk factors for acute urinary retention after rectal cancer surgery. Patients with two risk factors had a significantly higher risk of acute urinary retention than patients with none or one risk factor. Conclusions: This study suggests the maintenance of a urinary catheter for a period longer than 2 days and intraoperative fluid restriction to prevent acute urinary retention after rectal cancer surgery. [ABSTRACT FROM AUTHOR]

Background: Despite reports of the short-term benefits of end-to-side versus side-to-side anastomosis, we are aware of no prospective studies in which these methods were compared. We hypothesized the superiority of end-to-side over side-to-side anastomosis in terms of recovery after laparoscopic right hemicolectomy for colon cancer under an enhanced recovery program. Methods: From September 2016 to August 2019, 130 patients were randomly allocated to receive end-to-side or side-to-side anastomosis at a single tertiary hospital in Korea. The primary outcome was the cumulative recovery rate seven days after surgery, defined as the percentage of patients who met all four recovery criteria: diet tolerance, no analgesia, safe ambulation, and an afebrile status. Student's t test, the Mann–Whitney U test, the χ2 test, and Fisher's exact test were used to compare variables, as applicable. Results: The cumulative recovery rate at seven days did not differ between patients receiving end-to-side (92.3%, 60/65) or side-to-side anastomosis (92.3%, 60/65; P ≥ 0.999). The end-to-side and side-to-side groups had similar cumulative recovery rates at postoperative days 4, 5, and 6 (end-to-side vs. side-to-side: 41.5% vs 35.4%, P = 0.589; 73.8% vs 63.1%, P = 0.257; and 86.2% vs 81.5%, P = 0.634, respectively). None of the secondary endpoints differed for end-to-side vs. side-to-side anastomosis: the median length of postoperative hospitalization (5 [IQR 5–7] vs. 6 [IQR 5–7] days, respectively, P = 0.376), the 30-day complication rate (16.9% vs. 12.3%, respectively, P = 0.620), the enhanced recovery protocol failure rate (10.8% vs. 7.7%, respectively, P = 0.763), and the 30-day readmission rate (4.6% vs. 3.1%, respectively, P ≥ 0.999). Conclusions: End-to-side anastomosis was not superior to side-to-side anastomosis in terms of recovery criteria after laparoscopic right hemicolectomy. These findings do not provide evidence for a functional advantage of end-to-side compared to side-to-side anastomosis. [ABSTRACT FROM AUTHOR]

Epithelial–mesenchymal transition (EMT)-related cancers generally elicit low immune responses. EMT is regulated by several microRNAs (miRNAs) in cancers. Thus, this study aimed to evaluate the prognostic potential of EMT-related miRNAs as biomarkers in colorectal cancer (CRC). Formalin-fixed paraffin-embedded tumor and normal tissue and plasma samples were obtained from 65 patients with pathologically confirmed CRC. In addition, plasma samples were obtained from 30 healthy volunteers. Immunohistochemical staining for E-cadherin, ZEB1, PD-1, PD-L1, CD3, CD4, CD8, Foxp3, and CD68 was conducted on tissue samples. Droplet digital polymerase chain reaction (ddPCR) analysis was performed to evaluate miR-21-5p, 34a-5p, 138-5p, 200a-3p, 200b-5p, 200c-3p, 630, 1246, and 1290 expression in tissue samples and miR-630, 1246, and 1290 expression in plasma samples. miR-21-5p, 34a-5p, 630, 1246, and 1290 expression was higher in tumor tissues than in normal tissues (P < 0.05). EMT was significantly associated with reduced tumor-infiltrating T cells. Moreover, miR-21-5p, miR-34a-5p, miR-200a-3p, and miR-200c-3p expression was negatively correlated with T cell density (P < 0.05). High tissue levels of miR-200c-3p were associated with poor overall survival (OS) (P < 0.001). CRC patients with the EMT phenotype had poor OS; however, PD-L1 positivity and abundant PD-1 positive immune cells were correlated with better OS (P < 0.05). miR-1246 and miR-1290 levels were significantly higher in the plasma of patients with CRC than in the plasma of healthy controls (P < 0.05). High plasma levels of miR-1290 were correlated with advanced stage and poor OS (P < 0.05). The tissue expression of miR-200c-3p and plasma levels of miR-1290 measured by ddPCR indicate their potential as prognostic biomarkers for CRC. [ABSTRACT FROM AUTHOR]

This study aimed at determining the incidence and clinical implications of HER2 status in primary colorectal cancer (CRC). HER2 status was investigated in two retrospective cohorts of 365 consecutive CRC patients (cohort 1) and 174 advanced CRC patients with synchronous or metachronous distant metastasis (cohort 2). HER2 status was determined by performing dual-color silver in-situ hybridization (SISH), mRNA in-situ hybridization (ISH), and immunohistochemistry (IHC). The incidence of HER2 protein overexpression (IHC 2+/3+) was approximately 6% (22 of 365 in cohort 1; 10 of 174 in cohort 2). HER2 gene amplification was observed in 5.8% of the patients from cohort 1 and 6.3% of the patients from cohort 2. HER2 gene amplification was more frequently observed in CRCs located in the rectum than in the right and left colon (P = 0.013 in cohort 1; P = 0.009 in cohort 2). HER2 status, determined by IHC, ISH, and dual-color SISH, was not significantly associated with aggressive CRC behaviour or patients' prognosis in both the cohorts. Of the combined cohort with a total of 539 cases, the concordance rate was 95.5% between dual-color SISH and IHC detection methods. On excluding equivocally immunostained cases (IHC 2+), the concordance rate was 97.7%. HER2 mRNA overtranscription, detected by ISH, significantly correlated with protein overexpression and gene amplification (P<0.001). HER2 gene amplification was identified in a minority of CRC patients with high concordance rates between dual-color SISH and IHC detection methods. Although HER2 status did not predict patients' prognosis, our findings may serve as a basis for future studies on patient selection for HER2 targeted therapy. [ABSTRACT FROM AUTHOR]

Background: Self-expanding metallic stents (SEMSs) are used as a bridge to surgery in patients with obstructive colorectal cancer. However, the role of laparoscopic resection after successful stent deployment is not well established. We aimed to compare the oncologic outcomes of laparoscopic vs open surgery after successful colonic stent deployment in patients with obstructive left-sided colorectal cancer. Methods: In this multicenter study, 179 (97 laparoscopy, 82 open surgery) patients with obstructive left-sided colorectal cancer who underwent radical resection with curative intent after successful stent deployment were retrospectively reviewed. To minimize bias, we used inverse probability treatment-weighted propensity score analysis. The short- and long-term outcomes between the groups were compared. Results: Both groups had similar demographic and tumor characteristics. The operation time was longer, but the degree of blood loss was lower in the laparoscopy than in the open surgery group. There were nine (9.3%) open conversions. After adjustment, the groups showed similar patient and tumor characteristics. The 5-year disease-free survival (DFS) (laparoscopic vs open: 68.7% vs 48.5%, p = 0.230) and overall survival (OS) (laparoscopic vs open: 79.1% vs 69.0%, p = 0.200) estimates did not differ significantly across a median follow-up duration of 50.5 months. Advanced stage disease (DFS: hazard ratio [HR] 1.825, 95% confidence interval [CI]: 1.072–3.107; OS: HR 2.441, 95% CI 1.216–4.903) and post-operative chemotherapy omission (DFS: HR 2.529, 95% CI 1.481–4.319; OS: HR 2.666, 95% CI 1.370–5.191) were associated with relatively worse long-term outcomes. Conclusion: Stent insertion followed by laparoscopy with curative intent is safe and feasible; the addition of post-operative chemotherapy should be considered after successful treatment. [ABSTRACT FROM AUTHOR]

Aim: The aim was to determine the efficacy of probiotics in restoring bowel function following ileostomy reversal in patients with rectal cancer. Method: This was a pilot, randomized, double‐blind, placebo‐controlled trial. The probiotic used in this study, Lactobacillus plantarum CJLP243, was derived from kimchi. Patients were randomly allocated to a probiotic or placebo group and medication was taken once daily from preoperative day 1 to day 21. Primary outcomes were the Memorial Sloan Kettering Cancer Centre Bowel Function Index (MSKCC BFI) instrument and the low anterior resection syndrome score. The secondary outcomes were the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire C30 and CR29 questionnaire responses. Results: Forty patients were enrolled, and 36 patients (probiotics, n = 17; placebo, n = 19) completed the primary outcomes. Total scores for the MSKCC questionnaire (56.2 ± 12.0 vs. 55.0 ± 10.7, P = 0.356) and low anterior resection syndrome scores (33.3 ± 7.6 vs. 36.0 ± 5.3, P = 0.257) were not significantly different between the probiotic and placebo groups, respectively. In the MSKCC BFI, the postoperative dietary scale score at week 1 was significantly higher in the probiotic group (13.1 ± 3.8 vs. 9.0 ± 3.0, P < 0.001). There were no other significant differences between the two groups for any other questionnaire scores. Conclusion: There were no significant effects supporting the use of a probiotic for improved bowel function in patients following ileostomy reversal. Nevertheless, the administration of probiotics showed trends toward improvements in some subscale bowel function measures, suggesting further studies may be warranted. [ABSTRACT FROM AUTHOR]

Purpose: Some metastatic colorectal cancer (mCRC) patients receive conversion surgery (CS), including metastasectomy after palliative chemotherapy. Although targeted agents significantly improved the outcomes, the clinical outcome of CS in the targeted agent era has not yet been thoroughly investigated. Methods: We analyzed the clinical data of 96 mCRC patients who initially had unresectable liver- and/or lung-limited metastases and underwent first-line cetuximab or bevacizumab plus FOLFIRI between January 2013 and June 2017. Results: Liver-limited metastasis was seen in 44 patients (45.8%), lung-limited metastases in 21 patients (21.9%), and both liver and lung metastases in 31 patients (32.3%). Among them, 37 patients (38.5%) received cetuximab, and 59 patients (61.5%) received bevacizumab plus FOLFIRI. Overall response rate was 63.9% and 40.7%, respectively (p = 0.035). After median 8.7 (range 2.5–27.3) months, CS was performed in 11 patients (29.7%) in cetuximab group and 15 patients (25.4%) in bevacizumab group (p = 0.646). Median overall survival has not been reached in R0-resected patients (n = 23), during the median follow-up period of 22.5 (range 9.8–54.5) months. Median disease-free survival was 7.1 (95% CI 2.5–11.7) months: 11.0 (95% CI 3.1–19.0) months in cetuximab group and 3.2 (95% CI 0.0–7.8) months in bevacizumab group (p = 0.422). There was no progression after 18.5 months and disease-free survival reached a plateau at 19.9%. Conclusions: A substantial proportion of patients could receive CS after cetuximab or bevacizumab plus FOLFIRI chemotherapy. R0-resected patients had excellent overall survival, although 80.1% of them eventually experienced recurrence. Some patients could achieve durable disease-free state. [ABSTRACT FROM AUTHOR]

Background: Although monopolar electrocautery is preferred by many laparoscopic surgeons and is more cost-effective than bipolar or ultrasonic scissors, few studies have compared these outcomes between different monopolar electrocautery devices used in laparoscopic surgery. Therefore, this study compared the surgical outcomes between monopolar endo-hook versus endo-shears during laparoscopic right hemicolectomy for right colon cancer.Methods: Using a prospective database of patients treated at our institute, we analyzed the surgical outcomes of 358 consecutive patients with right colon cancer who underwent curative laparoscopic surgery with a monopolar endo-hook (n = 164) or endo-shears (n = 194) between March 2009 and March 2017.Results: There were no differences in age, sex, body mass index, American Society of Anesthesiologists' grade, previous operative history, or clinical stage between the endo-hook and endo-shears groups. The estimated blood loss was similar between the endo-hook and endo-shears groups (90.9 ± 60.3 vs. 92.0 ± 89.3 mL; P = 0.893). The number of harvested lymph nodes was greater in the endo-hook group (53.5 ± 20.3 vs. 48.1 ± 18.5; P = 0.008). Hospital stay was shorter in the endo-hook group (6.8 ± 2.2 vs. 7.8 ± 4.8 days; P = 0.013). Although chylous ascites was more frequent in the endo-hook group (21.3% vs. 7.7%, P < 0.001), the postoperative morbidity rate was lower in this group (9.8% vs. 18.0%; P = 0.025). All instances of chylous ascites healed spontaneously without intervention.Conclusions: This study showed that the use of a monopolar endo-hook during laparoscopic right hemicolectomy might permit more meticulous lymph-node dissection and reduce morbidity compared with the use of monopolar endo-shears. Therefore, we suggest that the outcomes of laparoscopic surgery might be associated with the type of electrocautery device used. [ABSTRACT FROM AUTHOR]

Background: Rectal preservation against medical advice after neoadjuvant chemoradiotherapy for rectal cancer may increase oncologic uncertainty. This study aimed to compare the oncologic outcomes of patients undergoing rectal preservation as intended by the surgeon, and the outcomes of patients refusing rectal resection against medical advice. Methods: The study population consisted of patients in whom the rectum was preserved after neoadjuvant chemoradiotherapy for clinical stage I–III mid or low rectal cancer between May 2003 and August 2017 (n = 2883); these patients were divided into those in whom rectal preservation was intended by their surgeon (intended rectal preservation, group A, n = 41) and those in whom the rectum was not resected against medical advice (unintended rectal preservation, group B, n = 101), defined as non-operative management or local excision. Results: The tumor distance, age, and performance status of patients were not significantly different between the groups, while the clinical T stage before chemoradiotherapy was lower in group A than in group B (P < 0.001). During the median follow-up period of 34 months (interquartile range 18.0–72.0 months), the 3-year overall survival in group B (59.7%) was worse than that in group A (90.1%; P < 0.001), and 80.2% of group B patients had residual or unknown disease status. Conclusions: This study showed that unintended rectal preservation increases oncologic risk after neoadjuvant chemoradiotherapy for rectal cancer regardless of short-term follow-up. Therefore, these findings could be shared with rectal cancer patients who choose to ignore medical advice after chemoradiotherapy to preserve their rectum. [ABSTRACT FROM AUTHOR]

Cancer stem cell (CSC) and ATP-binding cassette (ABC) transporters are associated with treatment resistance and outcomes of patients with cancer. The present study investigated the prognostic implications of pre-therapeutic expression of ABC transporters and CSC markers in patients with colon cancer (CC) who received adjuvant 5-fluorouracil, leucovorin and oxaliplatin combination therapy (FOLFOX-4). The immunohistochemical expression of 3 ABC transporters, including ABC subfamily C member 2 (ABCC2), ABCC3 and ABC subfamily G member 2 (ABCG2), and 3 CSC markers, including sex determining region Y-box 2 (SOX2), leucine-rich repeat-containing G protein-coupled receptor 5 and aldehyde dehydrogenase 1, were determined in 164 CC tissues from patients with stage III CC, who underwent postoperative FOLFOX-4 chemotherapy. The association between the protein expression and patients' prognoses was statistically analyzed. ABCG2 was associated with favorable overall survival rate (OS; P=0.001), and ABCC2, ABCG2 and SOX2 were associated with increased disease-free survival rate (DFS; P=0.001, 0.002 and 0.013, respectively). In multivariate analyses, ABCG2 was an independent prognostic factor for OS [hazard ratio (HR)=2.877; P=0.046], and ABCC2 and SOX2 were independent prognostic factors for DFS (HR=2.831; P=0.014; HR=2.558, P=0.020, respectively). ABCC2, ABCG2 and SOX2 may be promising prognostic markers for patients with CC receiving FOLFOX-4 therapy. [ABSTRACT FROM AUTHOR]

Purpose: Despite a high incidence of fecal incontinence following sphincter-preservation surgery (SPS), there are no definitive factors measured before ileostomy reversal that predict fecal incontinence. We investigated whether vector volume anorectal manometry before ileostomy reversal predicts major fecal incontinence following SPS in patients with mid or low rectal cancer. Methods: This longitudinal prospective cohort study comprised 173 patients who underwent vector volume anorectal manometry before ileostomy reversal. The Fecal Incontinence Severity Index was measured 1 year after the primary SPS and classified as major incontinence (FISI score ≥ 25) or continent/minor incontinence (FISI score < 25). Multivariable logistic regression analysis was used to identify predictors of major incontinence. Results: Ninety-two patients (53.1%) had major incontinence. Although tumor stage, location, and neoadjuvant chemoradiotherapy were comparable, the major incontinence group had lower resting pressure (28.4 vs. 34.3 mmHg, P = 0.027), greater asymmetry at rest (39.1% vs. 34.1%, P = 0.002) and squeezing (34.2% vs. 31.4%, P = 0.046), shorter sphincter length (3.3 vs. 3.7 cm, P = 0.034), and lower resting vector volume (143,601 vs. 278,922 mmHg2 mm, P < 0.001) compared with the continent/minor incontinence group. Resting vector volume was the only independent predictor of major incontinence (odds ratio = 0.675 per 100,000 mmHg2 mm, 95% confidence interval, 0.532–0.823; P = 0.006). Conclusions: This study revealed that resting vector volume before ileostomy reversal may predict major fecal incontinence. We suggest that the physiology of the anorectum should be discussed with patients before ileostomy reversal in patients at high risk of fecal incontinence. [ABSTRACT FROM AUTHOR]

Background: Three-dimensional (3D) imaging for laparoscopy was introduced to overcome the limitations of conventional two-dimensional (2D) imaging that lacked depth perception and spatial orientation. This study aimed to evaluate the effect of 3D imaging in laparoscopic colectomy with D3 lymphadenectomy for colon cancer.Methods: From February 2014 to October 2016, the prospective database of 278 consecutive patients with colon cancer was analyzed retrospectively; these patients underwent laparoscopic surgery with 2D (n = 111) and 3D (n = 167) imaging, with curative intent.Results: No difference was found in sex, body mass index, history of abdominal surgery, and American Society of Anesthesiologists grade between the 3D and 2D groups. The estimated blood loss was less in the 3D group than in the 2D group (50 mL [30-100 mL] versus 100 mL [50-100 mL], P < .001). The number of resected lymph nodes was higher in the 3D group (n = 47 [37.5-60] versus 41 [32-51.5], P = .001). However, a difference in operative time was not observed in both groups (150 minutes [125-175 minutes] versus 155 minutes [135-177.5 minutes], P = .186). Postoperative morbidity was similar in both groups (7.8% versus 8.1%, P = 1.000). Time to pass first flatus (3 days [2-4 days] versus 3 days [3-4 days], P = .746) and postoperative hospital stay (6 days [6-8 days] versus 6 days [6-7 days], P = .087) were also similar.Conclusions: This study shows that laparoscopic colectomy with D3 lymphadenectomy for colon cancer using 3D laparoscopic systems appears to be beneficial, with less blood loss, which should be addressed in prospective studies. [ABSTRACT FROM AUTHOR]

Background: The purpose of this study was to explore gene copy number (GCN) variation of EGFR, HER2, c-MYC, and MET in patients with primary colorectal cancer (CRC).Methods: Dual-colour silver-enhanced in situ hybridization was performed in tissue samples of 334 primary CRC patients. The amplification status (GCN ratio ≥2) and GCN gain (average GCN ≥4) data for the EGFR, HER2, c-MYC and MET genes were obtained. GCN variation was also assessed by the criterion of the 2013 ASCO/CAP guidelines for HER2 testing.Results: Amplification of EGFR, HER2, c-MYC and MET was detected in 8 (2.4%), 20 (6.0%), 29 (8.7%), and 14 (4.2%) patients, respectively. Of 66 patients with at least one amplified gene, five exhibited co-amplification of genes studied (HER2-MET co-amplification: two patients; HER2-c-MYC co-amplification: two patients; EGFR-c-MYC co-amplification: one patient). There were 109 patients with GCN gains of one or more genes (EGFR: 11/334, HER2: 29/334, c-MYC; 60/334, MET: 48/334) and 32.1% (35/109) had multiple GCN gains. When each GCN was assessed by the criterion of the ASCO/CAP 2013 guideline for HER2 testing, 116 people showed positive or equivocal results for one or more genes. The cumulative amplification status had no association with patients' outcome. However, the cumulative results of the GCN gain and GCN status determined according to the ASCO/CAP guideline had a significant prognostic correlation in the univariate analysis (P values of 0.006 and 0.022, respectively). In the multivariate analysis, GCN gain and GCN status were independent prognostic factors (P values of 0.010 and 0.017, respectively).Conclusions: In this study, we evaluated GCN variation of four genes in a large sample of Korean CRC patients. The amplification status was not related to patient outcome. However, the GCN gain and GCN status according to the ASCO/CAP 2013 guideline were independent prognostic factors. [ABSTRACT FROM AUTHOR]

In this study, we investigated the clinical relevance of CD274 (PD-L1) protein expression by tumor cells and tumor-infiltrating immune cells in colorectal cancer (CRC). To this end, 186 microsatellite instability-high (MSI-H) and 153 microsatellite stable (MSS) CRCs were subjected to immunohistochemistry (IHC) analysis for the expression of CD274 and mismatch repair proteins. CD274 expression was evaluated in tumor cells at the center (TC) and periphery (TP), and immune cells at the center (IC) and periphery (IP) of CRC. IHC slides stained for CD3 and CD8 were scanned using an Aperio ScanScope for precise calculation of tumor-infiltrating T cell density. Additionally, samples were screened for the B-Raf (BRAF)-V600E mutation using a Cobas 4800 System and IHC. In total, CD274, CD274, CD274, and CD274 were observed in 43 (23.1%), 47 (25.3%), 107 (57.5%), and 102 (54.8%) of the MSI-H CRCs examined, and in three (2.0%), four (2.6%), 47 (30.7%), and 56 (36.6%) of the 153 MSS CRCs tested. Meanwhile, intratumoral heterogeneity of CD274 expression in tumor cells and immune cells was detected in 24 (12.9%) and 47 (25.3%) MSI-H CRCs, respectively. Notably, in both MSI-H and MSS CRC, CD274 and CD274 were independently associated with improved prognosis ( P < 0.05), while BRAF mutation was associated with CD274, poor differentiation, sporadic type, and hMLH1(−)/hMSH2(+)/hMSH6(+)/PMS2(−) in MSI-H CRC ( P < 0.006). In conclusion, CD274 expression in tumor-infiltrating immune cells was an independent factor for improved prognosis in CRC patients. A deeper understanding of CD274 status may yield improved responses to future CRC immunotherapies. [ABSTRACT FROM AUTHOR]

Background: The purpose of our research was to determine the prognostic impact and clinicopathological feature of c-MYC and β-catenin overexpression in colorectal cancer (CRC) patients.Methods: Using immunohistochemistry (IHC), we measured the c-MYC and β-catenin expression in 367 consecutive CRC patients retrospectively (cohort 1). Also, c-MYC expression was measured by mRNA in situ hybridization. Moreover, to analyze regional heterogeneity, three sites of CRC including the primary, distant and lymph node metastasis were evaluated in 176 advanced CRC patients (cohort 2).Results: In cohort 1, c-MYC protein and mRNA overexpression and ß-catenin nuclear expression were found in 201 (54.8 %), 241 (65.7 %) and 221 (60.2 %) of 367 patients, respectively, each of which was associated with improved prognosis (P = 0.011, P = 0.012 and P = 0.033, respectively). Moreover, co-expression of c-MYC and ß-catenin was significantly correlated with longer survival by univariate (P = 0.012) and multivariate (P = 0.048) studies. Overexpression of c-MYC protein was associated with mRNA overexpression (ρ, 0.479; P < 0.001) and nuclear ß-catenin expression (ρ, 0.282; P < 0.001). Expression of c-MYC and ß-catenin was heterogeneous depending on location in advanced CRC patients (cohort 2). Nevertheless, both c-MYC and ß-catenin expression in primary cancer were significantly correlated with improved survival in univariate (P = 0.001) and multivariate (P = 0.002) analyses. c-MYC and ß-catenin expression of lymph node or distant metastatic tumor was not significantly correlated with patients' prognosis (P > 0.05).Conclusions: Co-expression of c-MYC and ß-catenin was independently correlated with favorable prognosis in CRC patient. We concluded that the expression of c-MYC and ß-catenin might be useful predicting indicator of CRC patient's prognosis. [ABSTRACT FROM AUTHOR]

Background: Stapled technique for ileocolic anastomosis is largely supported in previous studies. However, standard anastomotic configuration is not conclusive and studies are limited. This study aims to compare postoperative outcomes between side to side (S-S) and end to side (E-S) stapled anastomosis after laparoscopic right hemicolectomy underenhanced recovery program (ERP).Methods: Between October 2009 and November 2012, 89 patients (46 in S-S group, 43 in E-S group) who underwent laparoscopic right hemicolectomy for colon cancer and managed with ERP were included in the study. Recovery time and cumulative recovery rates, the length of hospital stays, complication rates were analyzed to compare both configurations.Results: The recovery time were not different between groups (S-S group, 135 hours [84-183.5] vs E-S group, 117 hours [94-143]; P = 0.349). Difference of cumulative recovery rates were observed in postoperative day 7 (S-S group, 71.7 % vs E-S group, 93.0 %; P = 0.019). The postoperative hospital stay were shorter in E-S group (S-S, 7 days [6-9] vs E-S, 6 days [5-7]; P = 0.003). The overall complication rates were lower in E-S group (26.1 % vs 4.6 %; P = 0.008). Anastomotic leakage was not observed in both groups.Conclusions: E-S configuration after laparoscopic right hemicolectomy showed favorable outcomes under enhanced recovery program. [ABSTRACT FROM AUTHOR]

Background: Anti-EGFR antibody–based treatment is an important therapeutic strategy for advanced colorectal cancer (CRC); despite this, several mutations—including KRAS, BRAF, and PIK3CA mutations, and HER2 amplification—are associated with the mechanisms underlying the development of resistance to anti-EGFR therapy. The aim of our study was to investigate the frequencies and clinical implications of these genetic alterations in advanced CRC. Methods: KRAS, BRAF, and PIK3CA mutations were determined by Cobas real-time polymerase chain reaction (PCR) in 191 advanced CRC patients with distant metastasis. Microsatellite instability (MSI) status was determined by a fragmentation assay and HER2 amplification was assessed by silver in situ hybridization. In addition, KRAS mutations were investigated by the Sanger sequencing method in 97 of 191 CRC cases. Results: Mutations in KRAS, BRAF, and PIK3CA were found in 104 (54.5%), 6 (3.1%), and 25 (13.1%) cases of advanced CRC, respectively. MSI-high status and HER2 amplification were observed in 3 (1.6%) and 16 (8.4%) cases, respectively. PIK3CA mutations were more frequently found in KRAS mutant type (18.3%) than KRAS wild type (6.9%) (P = 0.020). In contrast, HER2 amplifications and BRAF mutations were associated with KRAS wild type with borderline significance (P = 0.052 and 0.094, respectively). In combined analyses with KRAS, BRAF and HER2 status, BRAF mutations or HER2 amplifications were associated with the worst prognosis in the wild type KRAS group (P = 0.004). When comparing the efficacy of detection methods, the results of real time PCR analysis revealed 56 of 97 (57.7%) CRC cases with KRAS mutations, whereas Sanger sequencing revealed 49 cases (50.5%). Conclusions: KRAS mutations were found in 54.5% of advanced CRC patients. Our results support that subgrouping using PIK3CA and BRAF mutation or HER2 amplification status, in addition to KRAS mutation status, is helpful for managing advanced CRC patients. [ABSTRACT FROM AUTHOR]

Background: Although enhanced recovery programs (ERPs) have been proven to be beneficial after laparoscopic colon surgery, they may result in adverse clinical outcomes following failure. This study analyzed risk factors associated with ERP failure after laparoscopic colon cancer surgery.Methods: We analyzed the outcomes of 208 patients who underwent ERPs following laparoscopic colon cancer surgery between June 2007 and April 2013. The ERP included early oral feeding, early ambulation, and regular laxative administration. ERP failure was defined as postoperative hospital stay of more than 5 days related to postoperative complications, unplanned readmission within 30 days of surgery, or death.Results: Surgical procedures included anterior resection (n = 101), right hemicolectomy (n = 90), and left hemicolectomy (n = 17). The mean postoperative hospital stay was 6.5 ± 2.3 days (range 3-24 days). ERP failure occurred in 36 patients (17.3%), with no mortality; reasons included ileus (n = 14), wound infection (n = 4), chylous drainage (n = 3), anastomotic bleeding (n = 3), pneumonia (n = 1), or readmission (n = 11) owing to delayed complications. Univariable analysis showed that ERP failure was associated with proximal colon cancer, side-to-side anastomosis, longer operation time, increased blood loss, and longer resected specimen length. Multivariable analysis showed that side-to-side anastomosis [odds ratio (OR) 4.534; 95% confidence interval (CI) 1.902-10.811; P = 0.001] and increased blood loss (OR 1.004; 95% CI 1.001-1.008; P = 0.041) were independent risk factors for ERP failure.Conclusions: We showed that increased blood loss and side-to-side anastomosis in comparison with end-to-end anastomosis were independent risk factors associated with ERP failure after laparoscopic colon cancer surgery. This suggests that intraoperative elements may be important determinants to obtain successful postoperative recovery in the era of ERP. [ABSTRACT FROM AUTHOR]

Purpose: We aimed to evaluate the psychometric properties of the Korean version of the European Organization for Research and Treatment of Cancer (EORTC) Colorectal Cancer-Specific Quality of Life Questionnaire (QLQ-CR29), based on a sample of patients with colorectal cancer.Methods: A total of 123 patients treated for colorectal cancer participated in the validation study. Test-retest reliability was assessed using intra-class correlations from a random sample. Internal consistency reliability was estimated using Cronbach's α coefficient. Convergent and discriminant validity was analyzed with multi-trait scaling. Clinical validity was assessed in terms of clinical differences using known-group comparisons. Concurrent validity was determined by correlations with the EORTC QLQ-C30, which was a generic core questionnaire to evaluate issues common to different cancer sites and treatments.Results: The test-retest, administered to 35 patients, showed acceptable reproducibility (0.62-1.00) except the constipation scale of the QLQ-C30 (0.43). Cronbach's α coefficient (0.70-0.87) exceeded the 0.7 criterion. Multi-trait scaling analysis showed that multi-item scales met standards of convergent and discriminant validity. The known-group comparisons showed quality of life (QOL) differences between groups of patients based on tumor location, receipt of neoadjuvant therapy, and with/without a stoma. Correlations between the scales of the QLQ-CR29 and QLQ-C30 were low in most areas, whereas correlations in several areas with related content were higher.Conclusion: This study shows that the Korean version of the EORTC QLQ-CR29 is a reliable and valid tool for measuring QOL, as determined by application to a sample of Korean colorectal cancer patients. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to determine the incidence and clinicopathological significance of c-MYC gene copy-number (GCN) gain in patients with primary colorectal cancer (CRC). Methods: The c-MYC GCN was investigated in 367 consecutive CRC patients (cohort 1) by using dual-color silver in situ hybridization. Additionally, to evaluate regional heterogeneity, we examined CRC tissue from 3 sites including the primary cancer, distant metastasis, and lymph-node metastasis in 152 advanced CRC patients (cohort 2). KRAS exons 2 and 3 were investigated for mutations. Results: In cohort 1, c-MYC gene amplification, defined by a c-MYC:centromere of chromosome 8 ratio ≥ 2.0, was detected in 31 (8.4%) of 367 patients. A c-MYC GCN gain, defined by ≥ 4.0 c-MYC copies/nucleus, was found in 63 (17.2%) patients and was associated with poor prognosis (P = 0.015). Multivariate Cox regression analysis showed that the hazard ratio for c-MYC GCN gain was 2.35 (95% confidence interval, 1.453–3.802; P < 0.001). In a subgroup of stage II-III CRC patients, c-MYC GCN gain was significantly associated with poor prognosis by univariate (P = 0.034) and multivariate (P = 0.040) analyses. c-MYC protein overexpression was observed in 201 (54.8%) out of 367 patients and weakly correlated with c-MYC GCN gain (ρ, 0.211). In cohort 2, the c-MYC genetic status was heterogenous in advanced CRC patients. Discordance between GCN gain in the primary tumor and either distant or lymph-node metastasis was 25.7% and 30.4%, respectively. A similar frequency for c-MYC GCN gain and amplification was observed in CRC patients with both wild-type and mutated KRAS. Conclusions: c-MYC GCN gain was an independent factor for poor prognosis in consecutive CRC patients and in the stage II-III subgroup. Our findings indicate that the status of c-MYC may be helpful in predicting the patients’ outcome and for managing CRC patients. [ABSTRACT FROM AUTHOR]

Purpose: To compare the impact of postoperative chemoradiotherapy (CRT) versus adjuvant chemotherapy alone on recurrence and survival in patients with stage II and III upper rectal cancer undergoing curative resection. Materials and Methods: From our institutional database, 190 patients who underwent primary curative resection between 2003 and 2010 for stage II or III upper rectal cancer were identified. None of the patients received preoperative CRT. Of these, 136 patients received postoperative chemotherapy alone (the CTx group) and 54 patients received postoperative CRT (the CRT group). The CRT group had poorer prognostic features (pT4, pN2, poor differentiation, or involved resection margin) compared with the CTx group. To reduce the impact of treatment selection bias on treatment outcomes, propensity score-matching analysis was used. Results: The matched cohort consisted of 50 CRT and 50 CTx patients with a median follow-up period of 76 and 63 months, respectively. In the matched cohort, CRT resulted in an improved 5-year local control (98.0% vs. 85.2%, p = 0.024) and overall survival rate (89.9% vs. 69.8%, p = 0.021) compared with CTx. In the subgroup analysis to identify subpopulations of patients that benefit most from receiving CRT, local recurrence did not occur in patients who did not have poor prognostic features regardless of the receipt of CRT. For patients with any poor prognostic features, CRT resulted in an improved 5-year local control compared with CTx (96.4% vs. 70.7%, p = 0.013). Conclusions: After adjusting for clinicopathologic factors by propensity score-matching, postoperative CRT was associated with improved local control and overall survival in stage II and III upper rectal cancer. Our results suggest that surgery followed by chemotherapy alone is acceptable for patients who did not have poor prognostic features, while additional radiotherapy should be given for patients who have any poor prognostic features. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to elucidate the effect of decreased muscle mass on the toxicity and survival of patients with colon cancer treated with adjuvant chemotherapy after surgery. Methods: We reviewed the data of 229 consecutive patients with stage III colon cancer who received adjuvant oxaliplatin, 5-fluorouracil, and leucovorin chemotherapy at a single center between 2003 and 2010. Baseline muscle mass was assessed by measuring the cross-sectional area of the psoas muscle at the level of the fourth lumbar vertebra on computed tomography images. Effects of muscle mass on toxicity of chemotherapy and survival were assessed. Results: The median age of the 229 patients was 61 years (range, 28-80) and 134 (58.5 %) were men. The mean psoas muscle mass index (PI, psoas muscle area divided by height [mm/m]) was 548.3. A 1 SD decrement in the PI was associated with an increase in all grade 3-4 toxicities in univariate (OR = 1.69, 95 % CI = 1.18-2.27) and multivariate (OR = 1.56, 95 % CI = 1.05-2.38) analyses. In univariate analysis, the PI was not associated with overall survival. However, multivariate analysis showed that a 1 SD decrement in the PI increased the hazard of overall mortality by 85 % (HR = 1.85, 95 % CI = 1.10-3.13). This effect of the PI on mortality was maintained in subgroup analyses, especially in older and obese patients. Conclusions: Decreased muscle mass was associated with increased risk of grade 3-4 toxicity and poor prognosis in patients with stage III colon cancer. [ABSTRACT FROM AUTHOR]

Summary: Background: Compared with open resection, laparoscopic resection of rectal cancers is associated with improved short-term outcomes, but high-level evidence showing similar long-term outcomes is scarce. We aimed to compare survival outcomes of laparoscopic surgery with open surgery for patients with mid-rectal or low-rectal cancer. Methods: The Comparison of Open versus laparoscopic surgery for mid or low REctal cancer After Neoadjuvant chemoradiotherapy (COREAN) trial was an open-label, non-inferiority, randomised controlled trial done between April 4, 2006, and Aug 26, 2009, at three centres in Korea. Patients (aged 18–80 years) with cT3N0–2M0 mid-rectal or low-rectal cancer who had received preoperative chemoradiotherapy were randomly assigned (1:1) to receive either open or laparoscopic surgery. Randomisation was stratified by sex and preoperative chemotherapy regimen. Investigators were masked to the randomisation sequence; patients and clinicians were not masked to the treatment assignments. The primary endpoint was 3 year disease-free survival, with a non-inferiority margin of 15%. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT0040951. Findings: We randomly assigned 340 patients to receive either open surgery (n=170) or laparoscopic surgery (n=170). 3 year disease-free survival was 72·5% (95% CI 65·0–78·6) for the open surgery group and 79·2% (72·3–84·6) for the laparoscopic surgery group, with a difference that was lower than the prespecified non-inferiority margin (–6·7%, 95% CI −15·8 to 2·4; p<0·0001). 25 (15%) patients died in the open group and 20 (12%) died in the laparoscopic group. No deaths were treatment related. Interpretation: Our results show that laparoscopic resection for locally advanced rectal cancer after preoperative chemoradiotherapy provides similar outcomes for disease-free survival as open resection, thus justifying its use. Funding: National Cancer Center, South Korea. [ABSTRACT FROM AUTHOR]

Background: We aimed to evaluate the clinical significance of microvessel density (MVD), lymphatic vessel density (LVD), and cancer-associated fibroblasts (CAFs) in relation to tumor location in advanced colorectal cancer (CRC). Methods: Using immunohistochemistry, we examined 181 advanced CRC patients for CD31 and D2-40 to measure MVD and LVD, respectively, α-smooth muscle actin (SMA) and desmin to identify CAFs, and PTEN to examine genetic changes of CAFs. To evaluate the regional heterogeneity of these properties, we examined tissue from four sites (the center and periphery of the primary cancer, a distant metastasis, and a lymph node metastasis) in each patient. Results: MVD, LVD, and CAFs showed significant heterogeneity with respect to the tumor location. LVD was the greatest in the center of the primary cancers and the amount of CAFs was the lowest in distant metastases. In distant metastases, those from the lung had higher LVD and MVD, but fewer CAFs than those from the liver, peritoneum, or ovary. Patients with low MVD and LVD in the center of the primary cancer had worse outcomes and patients with few CAFs in distant metastases and in the primary tumor had a lower survival rate. PTEN expression in CAFs in distant metastases was lost in 11 of 181 CRC patients (6.1%), which was associated with a worse prognosis. Conclusions: The microenvironment, including cancer-associated microvasculature and fibroblasts, is heterogeneous with respect to the tumor location in CRC patients. Therefore, heterogeneity of microenvironments should be taken into account when managing CRC patients. [ABSTRACT FROM AUTHOR]

Background: We conducted a randomized clinical trial to investigate the efficacy of the selective α-adrenoceptor antagonist tamsulosin in preventing acute voiding difficulty after rectal cancer surgery. Methods: A total of 94 rectal cancer patients with an International Prostate Symptom Score (IPSS) of ≤7 were randomly assigned (1:1) to the tamsulosin group (0.2 mg/day orally for 7 days) ( n = 47) or the control group ( n = 47). The primary endpoint was the reinsertion rate of the urinary catheter after its removal on postoperative day (POD) 3. The secondary endpoints included the maximum (Qmax) and average (Qavg) urinary flow rates on POD 3, and the voided volume (VV), residual urine volume (RU), and IPSS on POD 7. Analyses were based on an intention-to-treat population. Results: The reinsertion rate of the urinary catheter in the tamsulosin group was similar to that in the control group (23.4 vs. 21.3 %, respectively; p = 0.804). The postoperative voiding parameters and IPSS were not better in the tamsulosin group than in the control group after adjustments were made for the baseline measurements with analysis of covariance (Qmax, p = 0.537; Qavg, p = 0.399; VV, p = 0.645; RU, p = 0.703; IPSS, p = 0.761). Multivariate analysis revealed that being male was the only independent risk factor for reinsertion of the urinary catheter (odds ratio 0.239; 95 % confidence interval 0.069-0.823; p = 0.023). Conclusions: This controlled trial showed that tamsulosin at 0.2 mg/day does not prevent acute voiding difficulty after rectal cancer surgery. [ABSTRACT FROM AUTHOR]

Background: Computed tomography (CT) has become the predominant test for diagnosing acute appendicitis in adults. In children and young adults, exposure to CT radiation is of particular concern. We evaluated the rate of negative (unnecessary) appendectomy after low-dose versus standard-dose abdominal CT in young adults with suspected appendicitis. Methods: In this single-institution, single-blind, noninferiority trial, we randomly assigned 891 patients with suspected appendicitis to either low-dose CT (444 patients) or standard-dose CT (447 patients). The median radiation dose in terms of dose–length product was 116 mGy·cm in the low-dose group and 521 mGy·cm in the standard-dose group. The primary end point was the percentage of negative appendectomies among all nonincidental appendectomies, with a noninferiority margin of 5.5 percentage points. Secondary end points included the appendiceal perforation rate and the proportion of patients with suspected appendicitis who required additional imaging. Results: The negative appendectomy rate was 3.5% (6 of 172 patients) in the low-dose CT group and 3.2% (6 of 186 patients) in the standard-dose CT group (difference, 0.3 percentage points; 95% confidence interval, −3.8 to 4.6). The two groups did not differ significantly in terms of the appendiceal perforation rate (26.5% with low-dose CT and 23.3% with standard-dose CT, P=0.46) or the proportion of patients who needed additional imaging tests (3.2% and 1.6%, respectively; P=0.09). Conclusions: Low-dose CT was noninferior to standard-dose CT with respect to negative appendectomy rates in young adults with suspected appendicitis. (Funded by GE Healthcare Medical Diagnostics and others; ClinicalTrials.gov number, NCT00913380.) [ABSTRACT FROM PUBLISHER]

Background: We evaluated the association between a KRAS mutational status and various clinicopathologic features including the metastatic pattern in patients with metastatic or recurrent colorectal cancer (MRCRC). The concordance rates of the KRAS status between primary tumor sites and paired metastatic organs were also analyzed. Methods: The KRAS mutational status in codons 12, 13, and 61 from formalin-fixed sections of both primary tumors and related metastases was determined by sequencing analysis. One hundred forty-three Korean patients with MRCRC with available tissues (resection or biopsy) from both primary tumors and related metastatic sites were consecutively enrolled. Results: The KRAS mutation rate was 52.4% (75/143) when considering both the primary and metastatic sites. When the relationship between the KRAS status and initial metastatic sites at the time of diagnosis of MRCRC was analyzed, lung metastasis was more frequent as the initial metastatic site in patients with the KRAS mutation than in patients without the KRAS mutation (45.3% vs. 22.1%; P = 0.003). However, liver (37.3% vs. 70.6%; P < 0.001) or distant lymph node metastases (6.7% vs. 19.1%; P = 0.025) were less frequent as the initial metastatic organ in patients with the KRAS mutation than in patients without the KRAS mutation. The discordance rate of KRAS mutational status between primary and paired metastatic sites other than the lung was 12.3% (13/106). Compared with primary tumor sites, the KRAS discordance rate was significantly higher in matched lung metastases [32.4% (12/37)] than in other matched metastatic organs (P = 0.005). Conclusions: Organs initially involved by distant metastasis were different according to the KRAS mutational status in MRCRC patients. The concordance rate (87.7%) of the KRAS mutation status at metastatic sites other than the lung was generally high compared with primary tumor sites; however, lung metastasis had a high rate of KRAS discordance (32.4%). [ABSTRACT FROM AUTHOR]

Summary: Background: The safety and short-term efficacy of laparoscopic surgery for rectal cancer after preoperative chemoradiotherapy has not been demonstrated. The aim of the randomised Comparison of Open versus laparoscopic surgery for mid and low REctal cancer After Neoadjuvant chemoradiotherapy (COREAN) trial was to compare open surgery with laparoscopic surgery for mid or low rectal cancer after neoadjuvant chemoradiotherapy. Methods: Between April 4, 2006, and Aug 26, 2009, patients with cT3N0–2 mid or low rectal cancer without distant metastasis after preoperative chemoradiotherapy were enrolled at three tertiary-referral hospitals. Patients were randomised 1:1 to receive either open surgery (n=170) or laparoscopic surgery (n=170), stratified according to sex and preoperative chemotherapy regimen. Short-term outcomes assessed were involvement of the circumferential resection margin, macroscopic quality of the total mesorectal excision specimen, number of harvested lymph nodes, recovery of bowel function, perioperative morbidity, postoperative pain, and quality of life. Analyses were based on the intention-to-treat population. Patients continue to be followed up for the primary outcome (3-year disease-free survival). This study is registered with ClinicalTrials.gov, number NCT00470951. Findings: Two patients (1·2%) in the laparoscopic group were converted to open surgery, but were included in the laparoscopic group for analyses. Estimated blood loss was less in the laparoscopic group than in the open group (median 217·5 mL [150·0–400·0] in the open group vs 200·0 mL [100·0–300·0] in the laparoscopic group, p=0·006), although surgery time was longer in the laparoscopic group (mean 244·9 min [SD 75·4] vs 197·0 min [62·9], p<0·0001). Involvement of the circumferential resection margin, macroscopic quality of the total mesorectal excision specimen, number of harvested lymph nodes, and perioperative morbidity did not differ between the two groups. The laparoscopic surgery group showed earlier recovery of bowel function than the open surgery group (time to pass first flatus, median 38·5 h [23·0–53·0] vs 60·0 h [43·0–73·0], p<0·0001; time to resume a normal diet, 85·0 h [66·0–95·0] vs 93·0 h [86·0–121·0], p<0·0001; time to first defecation, 96·5 h [70·0–125·0] vs 123 h [94·0–156·0], p<0·0001). The total amount of morphine used was less in the laparoscopic group than in the open group (median 107·2 mg [80·0–150·0] vs 156·9 mg [117·0–185·2], p<0·0001). 3 months after proctectomy or ileostomy takedown, the laparoscopic group showed better physical functioning score than the open group (0·501 [n=122] vs −4·970 [n=128], p=0·0073), less fatigue (−5·659 [n=122] vs 0·098 [n=129], p=0·0206), and fewer micturition (−2·583 [n=122] vs 4·725 [n=129], p=0·0002), gastrointestinal (−0·400 [n=122] vs 4·331 [n=129], p=0·0102), and defecation problems (0·535 [n=103] vs 5·327 [n=99], p=0·0184) in repeated measures analysis of covariance, adjusted for baseline values. Interpretation: Laparoscopic surgery after preoperative chemoradiotherapy for mid or low rectal cancer is safe and has short-term benefits compared with open surgery; the quality of oncological resection was equivalent. Funding: The National Cancer Center, South Korea. [Copyright &y& Elsevier]

Purpose: To describe our experience with a bolus injection of 5-fluorouracil and leucovorin (FL) vs. capecitabine in terms of radiologic and pathologic findings in preoperative chemoradiotherapy (CRT) for locally advanced rectal cancer. Methods: The study enrolled 278 patients scheduled for preoperative CRT using two protocols with different chemotherapeutic regimens. Pelvic radiotherapy (50.4 Gy) was delivered concurrently with FL (n = 145) or capecitabine (n = 133). Surgery was performed 6 weeks after CRT completion. Tumor responses to CRT were measured using both radiologic and pathologic examination. Magnetic resonance volumetry was performed at the initial workup and just before surgery after completion of preoperative CRT. Post-CRT pathology tests were used to determine tumor stage and regression. Results: Radiologic examination showed that tumor volume decreased by 68.2% ± 20.5% in the FL group and 68.3% ± 22.3% in the capecitabine group (p = 0.970). Postoperative pathologic T stage determination showed that downstaging occurred in 44.3% of FL and 49.9% of capecitabine patients (p = 0.571). The tumor regression grades after CRT were Grade 1 (minimal response) in 22.6% and 21.0%, Grade 2 (moderate response) in 53.2% and 50.0%, Grade 3 (near-complete response) in 12.9% and 12.9%, and Grade 4 (complete response) in 11.3% and 16.1% of the FL and capecitabine groups, respectively (p = 0.758). Conclusion: In the present study, the radiologic and pathologic findings did not reveal significant differences in short-term tumor responses between preoperative FL and capecitabine CRT for locally advanced rectal cancer. Long-term results and a prospective randomized trial are needed. [Copyright &y& Elsevier]

Aims: We evaluated the clinical usefulness of a new unified glucose-insulin-potassium (GIK) regimen in a general surgical department.Methods: Surgical patients treated under the previous diverse GIK regimens (September 2016 to August 2017) and the new unified GIK regimen (September 2017 to August 2018) were identified in records of the Clinical Data Warehouse of Seoul National University Bundang Hospital. Serial and area under the curve (AUC) glucose levels, and percentages of time within the target glucose levels were compared in propensity score matched patients in the diverse GIK regimen and in the unified GIK regimen (n = 227 in each group).Results: The AUC of glucose at 6 h and 12 h was lower under the unified GIK regimen than the diverse GIK regimen. The percentage of target glucose levels was higher in the unified GIK regimen compared to the diverse GIK regimen (81.5% vs. 75.0%, P = 0.026), but the occurrence of hypoglycaemia did not differ significantly between groups.Conclusions: The unified GIK regimen was more effective than the diverse GIK regimen for glycaemic control and did not increase the number of patients developing hypoglycaemia. This validated written GIK regimen can be safely used in a general surgical department. [ABSTRACT FROM AUTHOR]

We focused on the utility of the droplet digital polymerase chain reaction (ddPCR) for detecting c-MYC gene copy number (GCN) gain in cell-free plasma and tumor tissue of colorectal cancer (CRC) patients. c-MYC GCN status was determined using dual-color silver in situ hybridization (SISH) and ddPCR in retrospective cohort 1 (192 CRC patients) and prospective cohort 2 (64 CRC patients). In cohort 1, c-MYC GCN gain was observed in 34 (17.5%) patients by SISH, and in 7 (3.6%) patients by ddPCR. c-MYC GCN by SISH significantly correlated with ddPCR results (ρ = 0.532, P < 0.001). Although 40 cases (20.7%) showed intratumoral genetic heterogeneity, it did not cause discordance in results obtained by the two methods. c-MYC GCN gain, by both SISH and ddPCR was independently correlated with worst prognosis (P = 0.002). In cohort 2, c-MYC GCN estimation in tissue by ddPCR was also significantly associated with results obtained by SISH (ρ = 0.349, P = 0.005), but correlated with plasma ddPCR with borderline significance (ρ = 0.246, P = 0.050). Additionally, detecting c-MYC GCN gain in plasma with ddPCR might have relatively low sensitivity but high specificity. Our study suggests that ddPCR can be a useful tool for detecting c-MYC GCN gain as a potential prognostic biomarker in CRC tissue samples; however, this will need further verification in plasma samples. [ABSTRACT FROM AUTHOR]

There is ongoing debate regarding the significance of complete or near-complete response after neoadjuvant chemoradiotherapy (CRT) for rectal cancer. This study assessed the prognostic value of the Dworak tumor regression grade (TRG) following neoadjuvant CRT and surgery primarily in patients with pathological stage (ypStage) II and III rectal cancer. The records of 331 patients who underwent neoadjuvant CRT followed by total mesorectal excision between 2004 and 2015 were retrospectively reviewed. Patients were categorized as having a good response (GR, TRG 3/4, n = 122) or a poor response (PR, TRG 1/2, n = 209). At a median follow-up of 65 months, five-year disease-free survival (DFS) was higher in the GR group than in the PR group (91.3% vs. 66.6%, p < 0.001). Patients with a GR and ypStage II disease had a five-year DFS that was indistinguishable from that of patients with ypStage 0–I disease (92.3% vs. 90.7%, p = 0.885). Likewise, patients with a GR and ypStage III disease had a five-year DFS similar to those with ypStage II disease (76.0% vs. 75.9%, p = 0.789). A new modified staging system that incorporates grouped TRG (GR vs. PR) was developed. The prognostic performance of this modified stage and the ypStage was compared with the Harrell C statistic. C statistic of the modified stage was higher than that of the ypStage (0.784 vs. 0.757, p = 0.012). The results remained robust after multivariate Cox regression analyses. In conclusion, a GR to neoadjuvant CRT is an independent predictor of good DFS and overall survival and further stratifies patients so as to estimate the risk of recurrence and survival among patients with ypStage II and III rectal cancer. [ABSTRACT FROM AUTHOR]