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Cancer has been the leading cause of death among Japanese since 1981, and many people die from it every year worldwide. While various measures have been taken to reduce the mortality rate of cancer, circulating tumor cells (CTCs) in the blood have been attracting attention in recent years. In the past, CTCs were detected by visual inspection by a physician or by an expensive machine, but these methods required much effort by the physician and required only EpCAM‐expressing cells to be detected. In addition, detection by image processing has been used, but it has the problem that the area of interest is only a part of the area and there are many false positives. In this paper, we propose a two‐step classification method that focuses on the shape and surface of cells. In the proposed method, multiple shape and surface features are obtained for four types of cells in blood images: Clusters, CTCs, Normal Cells, and Vertical Cells. Based on the features, cells are classified using a two‐step Random Forest and their accuracy is evaluated. Furthermore, the effectiveness of the proposed method is demonstrated by comparing it with conventional methods. [ABSTRACT FROM AUTHOR]

Background The anatomical pattern of lymph nodes spread differs between young (aged 45 years or younger) and elderly (aged 80 years or older) patients with stage III colon cancer and is poorly investigated. Methods Two groups of patients (young and elderly) with stage III colon cancer who underwent upfront extensive (D3) lymphadenectomy at eight Japanese centres between 1998 and 2018 were retrospectively analysed. The primary endpoint was the proportion of positive central lymph nodes. The lymph nodes spreading pattern and its prognostic impact on recurrence-free survival and overall survival in the two groups were also compared. Results Two hundred and ten young patients and 348 elderly patients were identified and compared. The total number of lymph nodes harvested and the total number of invaded lymph nodes were significantly higher in younger patients compared with elderly patients (median of 31.5 (3–151) versus 21 (3–116), P < 0.001 and median of 3 (1–21) versus 2 (1–25), P < 0.001 respectively). The proportion of positive central lymph nodes were higher in younger patients than in elderly patients (9.52% (95% c.i. 6.24 to 14.2%) versus 4.59% (95% c.i. 2.84 to 7.31%), P = 0.012). In multivariate models for recurrence-free survival, central lymph nodes invasion were identified as a poor prognostic factor in younger patients (HR 5.21 (95% c.i. 1.76 to 15.39)) but not in elderly patients (HR 1.73 (95% c.i. 0.80 to 3.76)). Conclusion Young patients with stage III colon cancer have a higher risk of central lymph nodes invasion, suggesting a more aggressive disease biology. The presence of central lymph nodes invasion are associated with a worse outcome in young patients. [ABSTRACT FROM AUTHOR]

A significant association exists between the gut microbiome and colorectal carcinogenesis, as well as cancer progression. It has been reported that Escherichia coli (E. coli) containing polyketide synthetase (pks) island contribute to colorectal carcinogenesis by producing colibactin, a polyketide‐peptide genotoxin. However, the functions of pks+E. coli in initiation, proliferation, and metastasis of colorectal cancer (CRC) remain unclear. We investigated the clinical significance of pks+E. coli to clarify its functions in CRC. This study included 413 patients with CRC. Pks+E. coli of tumor tissue and normal mucosal tissue were quantified using droplet digital PCR. Pks+E. coli was more abundant in Stages 0–I tumor tissue than in normal mucosal tissue or in Stages II–IV tumor tissue. High abundance of pks+E. coli in tumor tissue was significantly associated with shallower tumor depth (hazard ratio [HR] = 5.0, 95% confidence interval [CI] = 2.3–11.3, p < 0.001) and absence of lymph node metastasis (HR = 3.0, 95% CI = 1.8–5.1, p < 0.001) in multivariable logistic analyses. Pks+E. coli‐low and ‐negative groups were significantly associated with shorter CRC‐specific survival (HR = 6.4, 95% CI = 1.7–25.6, p = 0.005) and shorter relapse‐free survival (HR = 3.1, 95% CI = 1.3–7.3, p = 0.01) compared to the pks+E. coli‐high group. Pks+E. coli was abundant in Stages 0–I CRC and associated with CRC prognosis. These results suggest that pks+E. coli might contribute to carcinogenesis of CRC but might not be associated with tumor progression. [ABSTRACT FROM AUTHOR]

The prognosis for metastatic colorectal cancer patients (mCRC) with the BRAF V600E mutation is poor. BRAF V600E mutation frequency is reportedly low among Asians; however, the frequency of the BRAF V600E mutation in right-side colon cancer may not be low, even among Asians. In addition, spatial heterogeneity of BRAF V600E mutations also exists, as for RAS mutations. In this prospective observational study, we evaluated BRAF V600E mutations in cancer tissue and plasma of Japanese right-side colon cancer patients. 215 patients with right-side colon cancer were included. BRAF V600E mutations of cancer tissue and plasma were detected using droplet digital PCR. Blood plasma of patients with BRAF V600E mutations in cancer tissue or plasma was drawn at intervals throughout chemotherapy, and BRAF V600E mutations were evaluated. BRAF V600E mutations were detected in tissue samples from 35 of 215 patients (16.3%, cecum; 22.4%, ascending colon; 17.8%, and transverse colon; 9.0%). BRAF V600E mutations were detected in plasma of 10 of 215 (4.7%) patients. Eight of the ten patients had BRAF V600E mutations in their primary tumours, but two (both were Stage IV) patients did not. Sensitivity of liquid biopsy to detect BRAF V600E mutations was 10.3% (3/29) in Stage I-III patients and 83.3% (5/6) in Stage IV patients. BRAF V600E mutations are observed in right-side colon cancer at high frequency, especially in the cecum. BRAF V600E mutations can be detected in plasma and the detection rate is high in patients with advanced cancer. Spatial heterogeneity was observed using liquid biopsy. [ABSTRACT FROM AUTHOR]

Circulating tumour DNA (ctDNA) is very useful for purposes of cancer genetics; however, it has some limitations. Recently, ctDNA in body fluids, such as urine, sputum, and pleural effusion, has been investigated. The aim of this study was to evaluate the quantity of ctDNA derived from urine (trans -renal ctDNA) and the accuracy of KRAS mutation detection in relation to disease stage in colorectal cancer. Urine, plasma, and tissue samples were collected from consecutively resected colorectal cancer patients. DNA was extracted from each sample and the quantity was determined. From each DNA sample, KRAS mutations were detected using droplet digital PCR. 200 patients participated and KRAS mutations were detected in 84 patients (42.0%) from tumour tissue. The concentration of trans -renal ctDNA (trtDNA) was significantly lower than that of plasma; however, there was no significant difference between the sensitivity using ctDNA and that using trtDNA (29.8% VS 33.3%, p = 0.62). Concordance between these two tests was only 17.5%. Combination analysis (ctDNA + trtDNA) improved the sensitivity to 53.6%, and sensitivity was significantly higher than that of corresponding single assays (p = 0.003). In early cancer stages, trtDNA had greater sensitivity for detecting KRAS mutations than ctDNA (37.7% vs. 21.3%, p = 0.047). Conversely, it was less useful for advanced cancer stages (21.7% vs. 52.2%, p = 0.07). Notably, KRAS mutations were detected using ctDNA or trtDNA in 12 of 116 (10.3%) patients who had no KRAS mutations in their tissue samples. Conclusions: trtDNA and ctDNA have equal potential and combination analysis significantly improved the sensitivity. [ABSTRACT FROM AUTHOR]

High preoperative carcinoembryonic antigen (CEA) is a well-known risk factor for stage II-III colorectal cancer (CRC); however, in most cases, cancer does not recur. Conversely, postoperative CEA (post-CEA) is occasionally measured, and high post-CEA patients often develop recurrence; however, the clinical significance of post-CEA testing is unknown. The purpose of this study was to determine whether post-CEA elevation might indicate a poor prognosis for stage II-III CRC patients who underwent curative surgery. 482 patients with pathological stage II-III CRC were included. Univariate and multivariate analyses were performed to evaluate post-CEA levels. Multivariate analysis showed that elevated post-CEA (hazard ratio (HR): 3.14, P < 0.001), pathological lymph node metastasis (pN+), and pathological T4 (pT4) are associated with poor recurrence-free survival (RFS), and that elevated post-CEA (HR: 3.12; P = 0.002), pN+, pT4, age >70, and smoking are independently associated with poor overall survival. Subgroup analysis among stage III patients, in combination with the risk classification of the International Duration Evaluation of Adjuvant Chemotherapy (IDEA) study, showed that elevated post-CEA is a significant indicator of poor prognosis for RFS in both low-risk (73.8% vs. 21.2%, P < 0.001) and high-risk (49.9% vs. 25.0%, P = 0.04) groups. Post-surgical CEA elevation is independently associated with poor prognosis in stage II-III CRC. Adding post-CEA levels to the IDEA risk classification may provide a more reliable indicator of the need for individualized surveillance and adjuvant chemotherapeutic strategies. [ABSTRACT FROM AUTHOR]

The anatomical spread of lymph node (LN) metastasis is of practical importance in the surgical management of colon cancer (CC). We examined the effect of KRAS, BRAF, and microsatellite instability (MSI) on LN count and anatomical spread pattern in stage III CC. We determined KRAS, BRAF, and MSI status from stage III CC patients. Biomarker status was correlated with LN count and anatomical spread pattern, which was classified as sequential or skipped. Relapse‐free survival (RFS) was estimated using Kaplan‐Meier method, and correlations were assessed using log‐rank and Cox regression analyses. We analyzed 369 stage III CC patients. The proportion of KRAS mutant (mt), BRAF mt, and MSI‐high (H) were 44.2% (163/344), 6.8% (25/344), and 6.8% (25/344), respectively. The mean number of metastatic LN was higher in microsatellite‐stable (MSS) compared with MSI patients (3.5 vs. 2.7, P =.0406), although no differences were observed in accordance with KRAS or BRAF status. Interestingly, patients with BRAF mt and MSI‐H were less likely to harbor skipped metastatic LN (9.3% vs 20% and 4% vs 10.5% compared with BRAF wild‐type (wt) and MSS, respectively), but KRAS status did not predict anatomical spread pattern. Patients with KRAS wt and MSI‐H showed superior RFS compared with KRAS mt and MSS patients, respectively, whereas BRAF status did not affect RFS. Differences exist in the anatomical pattern of invaded LN in accordance with the molecular status of stage III CC. Patients with MSI‐H CC have less invaded and skipped LN, suggesting that a tailored surgical approach is possible. [ABSTRACT FROM AUTHOR]

Background: Circulating tumor DNA (ctDNA) detected before surgery disappears after complete surgical resection of the cancer. Residual ctDNA indicates minimal residual disease (MRD), which is a cause of recurrence. The presence of long‐fragment circulating cell‐free DNA (cfDNA) or methylated cfDNA also implies the presence of cancer. In this study, we evaluated the prognostic value of cfDNA methylation and long‐fragment cfDNA concentration in gastric cancer patients undergoing curative surgery Methods: Ninety‐nine gastric cancer patients were included. Peripheral blood samples were collected before and 1 month after surgery. In patients administered chemotherapy, samples were collected before starting chemotherapy. qPCR was performed to detect long‐ and short‐fragment LINE‐1. A plasma HELP (HpaII tiny fragment Enrichment by Ligation‐mediated PCR) assay to determine the concentration of HpaII small fragments was performed using ligation‐mediated PCR and HpaII was quantified as the HpaII:MspI ratio to detect methylation levels of cfDNA. Results: Overall survival (OS) of patients with low methylation levels before starting treatment was significantly worse than that of patients with high methylation levels (P = 0.006). In the 90 patients who underwent curative surgery, recurrence‐free survival (RFS) and OS of patients with low methylation levels before surgery were worse than those with high methylation levels (P=0.08 and P = 0.11, respectively). RFS and OS of patients with high concentrations of long‐fragment LINE‐1 after surgery were significantly worse than those with low concentrations of long‐fragment LINE‐1 (P = 0.009, P = 0.04). Conclusions: Pre‐surgical low methylation levels of LINE‐1 are a negative prognostic factor. Post‐surgical high concentrations of long‐fragment LINE‐1 indicate MRD and a high risk of recurrence. [ABSTRACT FROM AUTHOR]

The incidence of rare neuroendocrine tumors (NET) is rapidly increasing. Neuroendocrine carcinoma (NEC) is a NET with poorly differentiated histological features, high proliferative properties and associated poor prognoses. As these carcinomas are so rare and, thus, affect only a small number of patients allowing for few cell lines to be derived from patient biopsies, the histological, immunohistochemical, and clinical characteristics associated with colorectal NEC and NEC in other organs have yet to be clearly defined. Herein, we describe the establishment of a novel NEC cell line (SS‐2) derived from a tumor resection of the ascending colon from a 59‐year‐old Japanese woman. The histological, electron microscopic and immunohistochemical features of chromogranin A (CgA) as well as confirmation of synaptophysin positivity in this tumor were typical of those commonly observed in surgically resected colorectal NEC. Further, the Ki‐67 labeling index of the resected tumor was >20% and, thus, the tumor was diagnosed as an NEC of the ascending colon. The SS‐2 cell line maintained characteristic features to those of the resected tumor, which were further retained following implantation into subcutaneous tissues of nude mice. Additionally, when SS‐2 cells were seeded into ultra‐low attachment plates, they formed spheres that expressed higher levels of the cancer stem cell (CSC) marker CD133 compared to SS‐2 cells cultured under adherent conditions. SS‐2 cells may, therefore, contribute to the current knowledge on midgut NEC biological function while providing a novel platform for examining the effects of colorectal NEC drugs, including CSC. [ABSTRACT FROM AUTHOR]

We recruited 56 colorectal cancer patients and compared the mutational spectrum of tumor tissue DNA, circulating cell‐free DNA (ccfDNA) and circulating tumor cell (CTC) DNA (ctcDNA) to evaluate the potential of liquid biopsy to detect heterogeneity of cancer. Tumor tissue DNA, ccfDNA, and ctcDNA were extracted from each patient and analyzed using next‐generation sequencing (NGS) and digital PCR. To maximize yields of CTC, three antibodies were used in the capture process. From 34 untreated patients, 53 mutations were detected in tumor tissue DNA using NGS. Forty‐seven mutations were detected in ccfDNA, including 20 not detected in tissues. Sixteen mutations were detected in ctcDNA, including five not detected in tissues. In 12 patients (35.3%), mutations not found in tumor tissues were detected by liquid biopsy: nine (26.5%) in ccfDNA only and three (8.8%) in ctcDNA only. Combination analysis of the two liquid biopsy samples increased the sensitivity to detect heterogeneity. From 22 stage IV patients with RAS mutations in their primary tumors, RAS mutations were detected in 14 (63.6%) ccfDNA and in eight (36.4%) ctcDNA using digital PCR. Mutations not detected in primary tumors can be identified in ccfDNA and in ctcDNA, indicating the potential of liquid biopsy in complementing gene analysis. Combination analysis improves sensitivity. Sensitivity to detect cancer‐specific mutations is higher in ccfDNA compared with ctcDNA. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: Laparoscopic transabdominal preperitoneal repair (TAPP) is widely accepted in elective inguinal hernioplasty. However, given the scarcity of data, the feasibility and safety of TAPP in strangulated hernia cases have not yet been determined. Methods: We retrospectively evaluated the data from a consecutive series of 33 patients who had undergone surgery for acute strangulated inguinal hernia associated with suspected visceral ischemic damage by either TAPP (TAPP group, n = 11) or conventional open hernioplasty via the anterior approach (anterior group, n = 22). Results: The TAPP group had a significant longer surgical duration than the anterior group (147 vs 84 min) and relatively less blood loss. Incision and enlargement of the hernial orifice, which enables easy reduction of the strangulated organ, was performed in the last 7 of 11 cases in the TAPP group. The morbidity was lower in the TAPP group, but the difference was not statistically significant (18% vs 23%). The TAPP group had a significantly shorter postoperative hospital stay than the anterior group (7 vs 10 days). Conclusion: For surgeons with sufficient knowledge of the anatomy and expertise in reducing the strangulated organ, TAPP for strangulated inguinal hernia is at least comparable to open hernioplasty via the anterior approach in short‐term outcomes. [ABSTRACT FROM AUTHOR]

The genetic risk factors for anastomotic recurrence (AR) after curative surgery for colorectal cancer (CRC) are unclear. The present study is a single-center retrospective observational study that aimed to elucidate the association between the KRAS G13D mutation and AR in CRC. The present study included 21 patients with AR and 67 patients with non-anastomotic local recurrence (NALR) following curative surgery for CRC between January 2005 and December 2019. KRAS G13D mutation status was examined by droplet digital polymerase chain reaction. Data of clinicopathological findings and oncological outcomes were analyzed and compared between the AR group and the matched NALR group. The prevalence of the KRAS G13D mutation was significantly higher in the AR group (AR vs. NALR, 33.3 vs. 4.8%; P=0.047). Comparing the KRAS G13D mutation-positive and KRAS G13D mutation-negative patients in the AR group, there was no significant difference in the time from initial surgery to AR or resection rate of AR; however, all patients with KRAS G13D mutation who underwent resection of AR had subsequent recurrence within 2 years after resection, and overall survival was poor (3-year survival rate: Positive vs. negative, 68.6 vs. 90.9%; P=0.02). The prevalence of the KRAS G13D mutation was significantly higher in patients with AR, and KRAS G13D-mutant patients with AR had a poorer prognosis than those that were negative for the KRAS G13D mutation. In conclusion, postoperative surveillance and treatment strategies should be considered with attention to the possibility of AR and subsequent recurrence in KRAS G13D-mutant patients. [ABSTRACT FROM AUTHOR]

Angiogenesis is regulated by interactions between vascular endothelial growth factors (VEGFs) and VEGF receptors. VEGF-A, VEGF-D, placental growth factor (PlGF) and plasminogen activator inhibitor-1 (PAI-1) have tumor angiogenic activity. VEGF-A and PAI-1 levels in the blood may impact the activity of bevacizumab, and VEGF-D levels may similarly diminish the efficacy of ramucirumab. However, the dynamics of these angiogenic biomarkers for anti-VEGF therapy have not been well established; therefore, they were evaluated in this retrospective study, which included two cohorts. Cohort 1 included patients who were treated with cytotoxic agents and bevacizumab as first-line chemotherapy, and Cohort 2 comprised patients who were treated with cytotoxic agents and anti-VEGF drugs (bevacizumab, ramucirumab or aflibercept) as second-line chemotherapy. VEGF-A, VEGF-D, PlGF and PAI-1 levels were measured before starting chemotherapy and were re-assessed every 1–2 months until disease progression. Bevacizumab had reduced benefit as a first-line chemotherapeutant in patients with very low or very high levels of VEGF-A. Bevacizumab increased VEGF-A and PlGF levels, but not VEGF-D or PAI-1. Anti-VEGF drugs offered the greatest benefit to patients with high PAI-1 before first- and second-line chemotherapy. PAI-1 levels were not affected by anti-VEGF drugs. Since ramucirumab increased VEGF-D, it offered less benefit to patients with high VEGF-D in second-line chemotherapy. Conversely, aflibercept offered greater benefits to patients with high VEGF-D, without increasing VEGF-D. These biomarkers may be useful for the prediction of drug efficacy and may predict resistance to anti-VEGF drugs. [ABSTRACT FROM AUTHOR]

Objectives: To explore the predictive performance on the need for surgical intervention in patients with adhesive small bowel obstruction (ASBO) using machine-learning (ML) algorithms and investigate the optimal timing for transition to surgery., Methods: One hundred and six patients with ASBO who initially underwent long transnasal intestinal tube (LT) decompression were enrolled in this retrospective study. Traditional logistic regression analysis and ML algorithms were used to evaluate the risk of need for surgical intervention., Results: Non-operative management (NOM) by LT decompression failed in 28 patients (26%). Multivariate logistic regression analysis identified a drainage volume ≥665 ml via LT on day 1, interval between ASBO diagnosis and LT intubation, and small bowel dilatation at 48 h after LT intubation to be independent predictors of transition to surgery (odds ratios 7.10, 1.42, and 19.81, respectively; 95% confidence intervals 1.63-30.94, 1.00-2.02, and 3.04-129.10; P -values 0.009, 0.047, and 0.002). The random forest algorithm showed the best predictive performance of five ML algorithms tested, with an area under the curve of 0.889, accuracy of 0.864, and precision of 0.667 in the test set. 97.4% of patients without transition to surgery (n=78) had passes of first flatus until three days., Conclusions: This is the first study to demonstrate that ML algorithm can predict the need for surgery in patients with ASBO. The guideline recommended period for initial NOM of 72 h seems to be reasonable. These findings can be used to develop a framework for earlier clinical decision-making in these patients., Competing Interests: Conflicts of Interest There are no conflicts of interest., (Copyright © 2024 The Japan Society of Coloproctology.)

A peritoneal loose body (PLB) is tissue completely separated from other intraperitoneal organs. It is rare and usually found incidentally during laparotomy, examination, or autopsy. PLBs are usually located free in the peritoneal cavity and not in the extraperitoneal space. They are thought to originate when epiploic appendices are released into the abdominal cavity after ischemic necrosis. We report a case of a giant PLB outside the peritoneal cavity, adjacent to the rectovesical excavation, that was identified preoperatively inan asymptomatic 83-year-old man undergoing evaluation for cholecystolithiasis. Computed tomography revealed a mass with well-defined margins in the rectovesical excavation. The mass (diameter, 60 mm) consisted of a calcified core and peripheral soft tissue and did not appear to invade adjacent organs. Although there were no symptoms or tumor growth over time, we scheduled a laparoscopic extraction for definitive diagnosis. On laparoscopic exploration, a white ovoid mass was found in the rectovesical excavation; there was no invasion of adjacent organs. We diagnosed a giant PLB. Postoperative recovery was uneventful. Most PLBs are asymptomatic and do not require surgery, except when symptoms are present, when the PLB is large, or when malignancy is suspected. PLB is rarely extraperitoneal and is usually freely mobile; however, in our patient, it was fixed and outside the abdominal cavity, near the rectovesical fossa. Although it could not be diagnosed preoperatively as being extraperitoneal, imaging findings were typical of PLB; thus, it was possible to remove the mass laparoscopically without bowel resection.

Surgical site infections (SSIs) remain one of the most common serious surgical complications and are the second most frequent healthcare-associated infection. Patients with SSIs have a significantly increased postoperative length of hospital stay, hospital expenses, and mortality risk compared with patients without SSIs. The prevention of SSI requires the integration of a range of perioperative measures, and approximately 50% of SSIs are preventable through the implementation of evidence-based preventative strategies. Several international guidelines for SSI prevention are currently available worldwide. However, there is an urgent need for SSI prevention guidelines specific to Japan because of the differences in the healthcare systems of Japan versus western countries. In 2018, the Japan Society for Surgical Infection published SSI prevention guidelines for gastroenterological surgery. Although evidence-based SSI prevention guidelines are now available, it is important to consider the appropriateness of these guidelines depending on the actual conditions in each facility. A systemic inflammatory host response is a hallmark of bacterial infection, including SSI. Therefore, blood inflammatory markers are potentially useful in SSI diagnosis, outcome prediction, and termination of therapeutic intervention. In this review, we describe the current guideline-based perioperative management strategies for SSI prevention, focusing on gastroenterological surgery and the supplemental utility of blood inflammatory markers.

Kyphosis complicates abdominal surgery. Here, we report a case of rectal cancer in a patient with kyphosis who underwent successful laparoscopic surgery after a preoperative simulation. An 81-year-old woman with rectal cancer was admitted to our department, and laparoscopic surgery was planned. Physical examination revealed severe kyphosis. To ensure successful laparoscopic surgery, we conducted a detailed preoperative simulation, including three-dimensional CT simulations of port arrangement and anatomy, simulation of body position, selection of surgical instruments, and preoperative discussion with the anesthesiologist. We planned to insert the first port in the umbilical region for pneumoperitoneum and the camera port in the ventral region under pneumoperitoneum. We planned to insert the ports on the right side of the patient's body from the caudal regions, after considering the location of the inferior mesenteric artery and the limitations in degrees and space attributable to the costal arch and promontorium. Beach chair position was planned. We used a fan-shaped retractor and sponge retractor to remove the small intestine from the surgical view. In preoperative discussions with the anesthesiologist, we decided to maintain pneumoperitoneum pressure at less than 8 mm Hg during the operation, to safeguard respiratory function. Lower anterior resection with D2 lymph node dissection was performed, without intraoperative complications. At 2 years postoperatively, the patient was healthy with no signs of recurrence. Laparoscopic surgery appears to be a suitable choice for patients with kyphosis. We believe that preoperative simulation will result in successful outcomes.

Small-intestinal metastasis from lung cancer, although relatively rare, often causes intestinal obstruction, gastrointestinal perforation, and gastrointestinal bleeding, making it an oncological emergency. Many patients have undergone emergency surgery for treatment of rapid progression of an intestinal metastatic lesion; however, information on changes in such metastases is lacking. We analyzed data from 4 patients with small-intestinal metastases from lung cancer who were treated during a 10-year period (January 2011 to December 2020) and for whom data on change in tumor diameter were available. The average rate of growth in tumor volume was 1.48-fold (range, 1.31- to 1.78-fold) during a median observation period of 22 (4-39) days, a rapid increase. Histopathological analysis showed that, in patients with a high degree of primary tumor atypia, rapid tumor growth may be caused by intratumoral hemorrhage, which was the reason for the rapid increase in tumor volume.

Background: Anorectal melanoma is a rare disease with a poor prognosis. Symptoms are often nonspecific, which complicates preoperative diagnosis. Here, we describe the establishment of MELS, a new anorectal melanoma cell line derived from resection of a rectal tumor in a 40-year-old Japanese man., Methods: Histological, electron microscopic, and immunohistochemical features of S-100, HMB-45, Melan-A, and NSE positivity of the tumor were typical of surgically resected anorectal melanoma., Results: MELS cells are round or oval and have sharp thorn-like protrusions on some or all cell membranes. The cells form irregular attached colonies with numerous floating cells in two-dimensional culture. Transmission electron microscopy revealed that some MELS cells have cytoplasmic melanosomes. Immunocytochemically, MELS cells and surgical tissues had the same staining pattern. MELS cells had lower growth rates than Caco-2 (a colon adenocarcinoma cell line) and A375 (a cutaneous melanoma cell line) cells. Oxaliplatin and irinotecan were more effective in MELS cells than in Caco-2 and A375 cells., Conclusions: No previous report provided detailed clinical information on an anorectal melanoma cell line. Thus, MELS cells should improve our understanding of the biological characteristics of anorectal melanoma and provide a novel platform for examining the effects of therapies for anorectal melanoma.

Background: PIK3CA is associated with tumor progression, and the prevalence of PIK3CA mutation is high in breast cancer. Liquid biopsy offers convenient, noninvasive, and real-time insight into genetic alteration. In this study, we used liquid biopsy to detect PIK3CA mutations in patients with breast cancer., Methods: We recruited patients with histologically confirmed breast cancer and distant metastases between April 2020 and September 2020. Circulating DNA was extracted from plasma (ctDNA) and exosomes (exoDNA). PIK3CA mutations (exons 9 and 20) were analyzed by droplet digital PCR., Results: Of the 52 patients recruited, 16 had PIK3CA mutations in tumor tissue or blood: 9 had exon 9 mutations (E542K and E545K) and 8 had exon 20 mutations (H1047 L and H1047R). In 8 (15%) of the 52 patients, PIK3CA mutations were detected by liquid biopsies using ctDNA in 5 (9%), exoDNA in 6 (11%), and both ctDNA and exoDNA in 3 (6%). Of the 8 patients with PIK3CA mutations detected by liquid biopsies, 3 had no PIK3CA mutations in the primary tumors., Conclusions: PIK3CA mutations can be detected by liquid biopsy even in patients with no PIK3CA mutations in their primary tumors; thus, combination analysis using tissue and liquid biopsies can provide clinically useful information for patients with breast cancer.