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BACKGROUND: Despite growing evidence of the effectiveness of minimally invasive surgery (MIS) for primary gastric cancer, MIS for remnant gastric cancer (RGC) remains controversial due to the rarity of the disease. This study aimed to evaluate the surgical and oncological outcomes of MIS for radical resection of RGC. PATIENTS AND METHODS: Patients with RGC who underwent surgery between 2005 and 2020 at 17 institutions were included, and a propensity score matching analysis was performed to compare the short- and long-term outcomes of MIS with open surgery. RESULTS: A total of 327 patients were included in this study and 186 patients were analyzed after matching. The risk ratios for overall and severe complications were 0.76 [95% confidence interval (CI): 0.45, 1.27] and 0.65 (95% CI: 0.32, 1.29), respectively. The MIS group had significantly less blood loss [mean difference (MD), -409 mL; 95% CI: -538, -281] and a shorter hospital stay (MD, -6.5 days; 95% CI: -13.1, 0.1) than the open surgery group. The median follow-up duration of this cohort was 4.6 years, and the 3-year overall survival were 77.9% and 76.2% in the MIS and open surgery groups, respectively [hazard ratio (HR), 0.78; 95% CI: 0.45, 1.36]. The 3-year relapse-free survival were 71.9% and 62.2% in the MIS and open surgery groups, respectively (HR, 0.71; 95% CI: 0.44, 1.16). CONCLUSIONS: MIS for RGC showed favorable short- and long-term outcomes compared to open surgery. MIS is a promising option for radical surgery for RGC.

Intensive local treatment comprising total mesorectal excision (TME) with selective lateral pelvic lymph node dissection (LPND) after neoadjuvant chemoradiotherapy (CRT) for locally advanced rectal cancer (LARC) has received attention among clinicians treating rectal cancer. It remains unclear whether adjuvant chemotherapy (ACT) after intensive local treatment is beneficial for these patients. We evaluated the oncologic benefit of ACT for patients with LARC who received intensive local treatment.This international multicentre retrospective cohort study included 737 patients treated in Japan and Korea between 2010 and 2017. The effectiveness of ACT on recurrence-free survival (RFS) was evaluated using univariable and multivariable Cox proportional hazards models, with subgroup analyses to identify subpopulations potentially benefiting from ACT.The median follow-up was 49 months; the 5-year RFS and local recurrence rates for the entire cohort were 72.1% and 4.9%, respectively; 514 patients (69.7%) received adjuvant chemotherapy, without an oncologic benefit (hazard ratio, 1.14; 95% confidence interval [CI]: 0.79-1.68) demonstrated in the multivariable Cox regression analysis. In subgroup analyses, the distributions of the 95% CI in patients aged ≥70 years and those with ypStage 0 tended to place a disproportionate emphasis that favoured the non-ACT treatment strategy.Despite achieving good local control with intensive local treatment strategy, the effectiveness of ACT for the LARC patients with CRT followed by TME with selective LPND was not proved. Elderly patients and those with ypStage0 may not receive benefit from ACT after CRT and TME ± LPND.

Identifying lateral pelvic lymph node (LPN) metastasis in low rectal cancer is crucial before treatment. Several risk factors and prediction models for LPN metastasis have been reported. However, there is no useful tool to accurately predict LPN metastasis. Therefore, we aimed to construct a nomogram for predicting LPN metastasis in rectal cancer.We analyzed the risk factors for potential LPN metastasis by logistic regression analysis in 705 patients who underwent primary resection of low rectal cancer. We included patients at 49 institutes of the Japan Society of Laparoscopic Colorectal Surgery between June 2010 and February 2012. Clinicopathological factors and magnetic resonance imaging findings were evaluated. The nomogram performance was assessed using the c-index and calibration plots, and the nomogram was validated using an external cohort.In the univariable logistic regression analysis, age, sex, carcinoembryonic antigen, tumor location, clinical T stage, tumor size, circumferential resection margin (CRM), extramural vascular invasion (EMVI), and the short and long axes of LPN and perirectal lymph node (PRLN) were nominated as risk factors for potential LPN metastasis. We identified a combination of the short axis of LPN, tumor location, EMVI, and short axis of PRLN as optimal for predicting potential LPN metastasis and developed a nomogram using these factors. This model had a c-index of 0.74 and was moderately calibrated and well-validated.This is the first study to construct a well-validated nomogram for predicting potential LPN metastasis in rectal cancer, and its performance was high.

Routine placement of a feeding jejunostomy tube (FJT) following esophagectomy remains controversial due to the risk of complications including small bowel obstruction (SBO). This study aimed to evaluate FJT placement following esophagectomy.This retrospective cohort study included consecutive 229 patients undergoing thoracoscopic esophagectomy between January 2010 and June 2020. Short-term outcomes, postoperative nutritional status, incidence of SBO, and long-term outcomes were compared between patients according to FJT placement.The total operative duration was significantly longer in the FJT group compared to the no FJT group (P 0.0001); however, no differences in overall or severe postoperative morbidity were observed. Body weight loss at discharge was significantly attenuated in patients with FJT (5% vs 7%, P = 0.001). Serum cholinesterase levels were significantly higher in patients with FJT (P = 0.002), while no difference was observed in serum albumin levels. At 6-month follow-up, no statistically significant differences were observed in serological markers or percentage body weight. The incidence of SBO was significantly higher in the FJT group (P = 0.006). The 5-year incidence of SBO was 12%. Patients in the FJT group had higher progression-free and overall survival compared to patients in the no FJT group (P = 0.041 and P = 0.033, respectively). A similar trend toward better survival in the FJT group was observed after propensity score matching.Routine placement of FJT significantly improves postoperative nutritional status and may contribute to improved long-term survival but is associated with increased long-term risk of SBO.

[Background] Elective laparoscopic surgery is now widely accepted in the treatment of abdominal diseases because of its minimal invasiveness and rapid postoperative recovery. It is also used in the emergency setting for the diagnosis and treatment of acute diffuse peritonitis regardless of the causative disease. However, the value of laparoscopy in acute diffuse peritonitis remains unclear. In this study we aimed to show trends in the use of laparoscopy over time and compare the real-world performance of laparoscopic surgery with that of open surgery for acute diffuse peritonitis due to gastrointestinal perforation. [Methods] We extracted data from the National Clinical Database, a nationwide surgery registration system in Japan, for patients with a diagnosis of acute diffuse peritonitis due to gastroduodenal or colorectal perforation between 2016 and 2019. Trends in the use of laparoscopy over time were identified. Patient characteristics, laboratory findings, surgical findings, and postoperative complications were compared between laparoscopic surgery and open surgery. [Results] Patients in poor condition and those with abnormal laboratory findings tended to undergo open surgery. Anesthesia time and operating time were longer for laparoscopic surgery in patients with gastroduodenal perforation but shorter in those with colorectal perforation. Fewer complications occurred in patients who underwent laparoscopic surgery. The number of institutions where laparoscopic surgery was performed and the proportion of the use of laparoscopy at each institution increased over time. [Conclusion] The use of laparoscopy is becoming common in surgery for acute diffuse peritonitis due to gastrointestinal perforation. This approach may be a useful option for acute diffuse peritonitis.

Patients at risk of recurrence after curative surgery for rectal cancer usually receive adjuvant chemotherapy. Postoperative recovery after low anterior resection (LAR) for rectal cancer can be improved by placement of a diverting stoma to reduce anastomotic leakage. However, it remains unclear how a diverting stoma affects administration of adjuvant chemotherapy in these patients. We identified Japanese patients with rectal cancer who underwent LAR in 2014 and received adjuvant chemotherapy within 12 months of surgery in the National Database of Health Insurance Claims and Specific Health Checkups of Japan. Doses of five types of chemotherapy administered (tegafur/uracil, tegafur/gimeracil/oteracil potassium, capecitabine, 5-fluorouracil, and oxaliplatin) were assessed according to the presence or absence of diverting stoma and the timing of stoma closure. There was no significant difference in the cumulative doses of chemotherapy administered in the 12 months after LAR between patients with and without diverting stoma, but more doses were administered in the early postoperative period (0–2 months after LAR) in patients without diverting stoma. Also, more doses of chemotherapy, regardless of type, were administered in the late closure group (7–12 months after LAR) than in the early closure (≤ 6 months) and no closure groups. Presence of a diverting stoma did not influence the dose of adjuvant chemotherapy administered within 12 months after LAR but could have delayed the start of adjuvant chemotherapy. Patients with late closure of a diverting stoma received more doses of adjuvant chemotherapy administered over 12 months.

ASO Visual Abstract

We started robot-assisted minimally invasive esophagectomy (RAMIE) in 2012 using da Vinci S. After the reimbursement in the national insurance system in 2018, RAMIE has been indicated as an institutional standard surgery simply depending on the da Vinci availability. Our early series of 45 RAMIEs showed significantly less postoperative morbidity (p = 0.03) mainly due to less pulmonary complication (p = 0.006) compared to conventional minimally invasive esophagectomy using propensity score matching (Ann Surg Oncol. 2020). This study aims to retrospectively evaluate the feasibility of RAMIE and to demonstrate our standardized RAMIE with updated data. Our surgical technique is as follows. A patient is placed in a prone position with both lung ventilation with 8-10 mmHg artificial pneumothorax. In the upper mediastinum, the thoracic duct is usually preserved unless there is tumor invasion. Then, the tracheoesophageal arteries flowing into the visceral sheath over the recurrent laryngeal nerve (RLN) are divided first and RLN is isolated laterally. Then, the lymphatic tissue is dissected from the trachea. This procedure is identical on both sides of RLN nodal dissection. By January 2022, 89 RAMIEs (S: 6 cases and Xi: 83 cases) were performed. Thoracic operation time was 348 min and console time was 296 min. Intraoperative blood loss was 80 g and the number of harvested thoracic nodes is 23. There was no conversion from RAMIE to MIE nor to open procedure. Overall severe postoperative morbidity (Clavien-Dindo Grade 3 or higher) was 17% (15/89) and clinically relevant postoperative recurrent laryngeal nerve palsy (Clavien-Dindo Grade 2 or higher) was 10% (9/89). There was no postoperative mortality. RAMIE was safe and feasible.

Aim Randomized controlled trials (RCT) are the gold standard in surgical research, and case‐matched studies, such as studies with propensity score matching, are expected to serve as an alternative to RCT. Both study designs have been used to investigate the potential superiority of laparoscopic surgery to open surgery for rectal cancer, but it remains unclear whether there are any differences in the findings obtained using these study designs. We aimed to examine similarities and differences between findings from different study designs regarding laparoscopic surgery for rectal cancer. Methods Systematic review and meta‐analyses. A comprehensive literature search was conducted using PubMed, Scopus, and Cochrane. RCT, case‐matched studies, and cohort studies comparing laparoscopic low anterior resection and open low anterior resection for rectal cancer were included. In total, 8 short‐term outcomes and 3 long‐term outcomes were assessed. Meta‐analysis was conducted stratified by study design using a random‐effects model. Results Thirty‐five studies were included in this review. Findings did not differ between RCT and case‐matched studies for most outcomes. However, the estimated treatment effect was largest in cohort studies, intermediate in case‐matched studies, and smallest in RCT for overall postoperative complications and 3‐year local recurrence. Conclusion Findings from case‐matched studies were similar to those from RCT in laparoscopic low anterior resection for rectal cancer. However, findings from case‐matched studies were sometimes intermediate between those of RCT and unadjusted cohort studies, and case‐matched studies and cohort studies have a potential to overestimate the treatment effect compared with RCT., This article reports on similarities and differences in findings of randomized controlled trials (RCTs), case‐matched studies, and cohort studies, as revealed by meta‐analyses of previously published studies on laparoscopic low anterior resection (LAR) for rectal cancer. Results of case‐matched studies were often similar to those of RCTs in terms of outcomes of laparoscopic LAR for rectal cancer. However, case‐matched studies occasionally overestimate the effects of interventions compared to RCTs.

Data regarding risk factors for recurrence in stage I colorectal cancer patients are limited. The aim of this study was to clarify the existence of a high-recurrence-risk population among stage I colorectal cancer patients.This analysis included 7,539 stage I colorectal cancer patients treated between 1997 and 2012 at 24 leading hospitals in Japan. Risk factors for time to recurrence were evaluated using a Cox proportional hazards model, and a high-risk group for recurrence was identified. Prognostic outcomes of high-risk stage I colorectal cancer patients were compared with those of low-risk stage I and stage II patients.Multivariable analyses identified left-sided location (hazard ratio [HR]: 1.65, 95% confidence interval [CI]: 1.09-2.58), T2 tumors (HR: 1.80, 95% CI: 1.21-2.66), and lymphatic invasion (HR: 1.55, 95% CI: 1.05-2.28) as risk factors for recurrence in stage I colon cancer, and patients with these three risk factors were classified as high risk. For stage I rectal cancer, patients with poor differentiation (HR: 2.86, 95% CI: 1.21-5.69), T2 tumors (HR: 1.53, 95% CI: 1.07-2.23), and venous invasion (HR: 1.51, 95% CI: 1.08-2.13) were identified as high risk. The Kaplan-Meier analysis of cumulative recurrence rate and recurrence-free survival revealed that the high-risk stage I colorectal cancer patients have poorer clinical outcomes than the low-risk patients.Although stage I colorectal cancer patients generally have a favorable prognosis after curative surgery, poorer prognosis was observed in high-risk stage I colorectal cancer patients than in low-risk patients.

The present article reviews the theory of data privacy and confidentiality in statistics and computer science, to modernize the theory of anonymization. This effort results in the mathematical definitions of identity disclosure and attribute disclosure applicable to even synthetic data. Also differential privacy is clarified as a method to bound the accuracy of population inference. This bound is derived by the Hammersley-Chapman-Robbins inequality, and it leads to the intuitive selection of the privacy budget $$\epsilon$$ of differential privacy.

There is no standard chemotherapy available for unresectable or metastatic small bowel adenocarcinoma (SBA) because of its rarity. This systematic review aims to assess the efficacy and safety of chemotherapy for patients with unresectable or metastatic SBA. In accordance with the PRISMA statements, literature search was conducted using PubMed, Scopus, and the Cochrane Central Register of Controlled Trials. The included studies were prospective randomized, nonrandomized, or observational studies. Risk of bias was assessed the ROBINS-I tool. Seven prospective single-arm Phase II studies were included in this review. Six of them were assessed as having a moderate risk of bias and one as having a serious risk of bias. A meta-analysis was not performed, because the studies were single-arm. Systemic chemotherapy based on fluoropyrimidine regimens achieved favorable outcomes with acceptable adverse effects as a first therapy; however, the regimens differed in each study. The object response rate was 18–50%, and the disease control rate was 29–87%. With 5-fluorouracil, adriamycin, and mitomycin-C regimen, one treatment-related death occurred. A second line of therapy including chemotherapy with nab-paclitaxel also showed favorable efficacy. The object response rate was 20%, and the disease control rate was 50%. Systemic chemotherapy based on fluoropyrimidine regimens was mainly used for unresectable or metastatic SBA. While it may achieve favorable outcomes with acceptable adverse effects, further evidence is needed.

Many systematic reviews have been published to evaluate the clinical benefits of robotic surgery for gastric cancer. However, these reviews have investigated various outcomes and differ considerably in quality. In this overview, we summarize the findings and quality of these reviews. A comprehensive literature search was conducted using PubMed, Scopus, and the Cochrane Central Register of Controlled Trials to identify systematic reviews and meta-analyses that compared robotic surgery with laparoscopic surgery for gastric cancer. We summarized the results of the meta-analyses and evaluated the quality of the reviews using the AMSTAR-2 tool. The literature search identified 14 eligible reviews. The reviews showed that estimated blood loss was significantly less and time to resumption of oral intake was significantly shorter in patients who underwent robotic surgery than in those who underwent laparoscopic surgery. However, no significant differences in other outcomes were found between the two types of surgery. The quality of the included reviews was judged to be critically low. In conclusion, the available evidence, albeit of critically low quality, suggests that robotic surgery decreases estimated blood loss and shortens the time to resumption of oral intake in patients with gastric cancer. There is currently no high-quality evidence that robotic surgery has clinical benefits for gastric cancer patients.

The supraclavicular lymph nodes (SCLNs) have been regarded as regional nodes for esophageal squamous cell carcinoma (ESCC) in Japan and eastern Asian countries, whereas their involvement has been regarded as distant metastasis in Western countries. The importance of thorough dissection of the lymphatic chain along the recurrent laryngeal nerve, including the cervical paraesophageal nodes, has become well understood; therefore, the contemporary clinical question is whether prophylactic SCLN dissection (SLND) in addition to cervical paraesophageal node dissection is beneficial for patients with ESCC. We analyzed studies comparing esophagectomy with SLND vs. esophagectomy without SLND, in both of which cervical paraesophageal node dissection had been completed, based on a comprehensive literature search of the PubMed, Scopus, and Cochrane databases. Our meta-analysis focused on two long-term outcomes: 3-year and 5-year overall survival (OS) rates; and three short-term outcomes: pneumonia, recurrent nerve palsy, and anastomotic leakage. Four studies, with a collective total of 1584 patients were included in the review. No significant differences were found between esophagectomy with SLND vs. esophagectomy without SLND in the meta-analysis of both long-term (3-year and 5-year OS; risk ratio 1.09, 95% CI 0.94-1.26, P = 0.28, and risk ratio 1.14, 95% CI 0.96-1.35, P = 0.15, respectively) and short-term outcomes. Based on our analysis, no clear data support prophylactic SLND on the cervical paraesophageal node dissection.

357 Background: Remnant gastric cancer (RGC) is defined as a cancer arising in the remnant stomach after initial gastrectomy, regardless of the previous disease or surgical procedure. Despite growing evidence of the effectiveness of minimally invasive surgery (MIS) for primary gastric cancer, MIS for RGC remains controversial due to the rarity of the disease. This study aimed to evaluate the surgical and oncological outcomes of MIS for radical resection of RGC. Methods: We collected the data of patients with RGC who underwent surgery with curative intent between 2005 and 2020 from 17 institutions in Japan, and performed a propensity score (PS) matching analysis to compare the short- and long-term outcomes of MIS with open surgery. Results: A total of 327 patients were included in this study and 186 patients were analyzed after matching. The risk ratios for overall and severe complications were 0.76 (95% confidence interval [CI]: 0.45–1.27) and 0.65 (95% CI: 0.32–1.29), respectively. The MIS group had significantly less blood loss (50 ml vs. 361 ml, P

This is a protocol for a Cochrane Review (intervention). The objectives are as follows: To evaluate the efficacy and safety of splenectomy in people undergoing total gastrectomy for gastric cancer.

This is a protocol for a Cochrane Review (intervention). The objectives are as follows: To compare the efficacy and safety the anterior and posterior mediastinal reconstruction routes after esophagectomy in patients with esophageal cancer.

Background Gastric cancer is the fifth most common cancer diagnosed worldwide. Due to improved early detection rates of gastric cancer and technological advances in treatments, a significant improvement in survival rates has been achieved in people with cancer undergoing gastrectomy. Subsequently, there has been increasing emphasis on postgastrectomy syndrome (e.g. fullness, delayed emptying, and cold sweat, amongst others) and quality of life postsurgery. However, it is uncertain which types of reconstruction result in better outcomes postsurgery. Objectives To assess the evidence on health-related quality of life and safety outcomes of Roux-en-Y and Billroth-I reconstructions after distal gastrectomy for people with gastric cancer. Search methods We searched the Cochrane Library and the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase on 4 May 2021. We checked the reference lists of the included studies and contacted manufacturers and professionals in the field. There were no language restrictions. Selection criteria Randomised controlled trials (RCTs) allocating participants to Roux-en-Y reconstruction or Billroth-I reconstruction after distal gastrectomy for gastric cancer. Data collection and analysis Two review authors independently screened studies identified by the search for eligibility and extracted data. The primary outcomes were health-related quality of life after surgery and incidence of anastomotic leakage. The secondary outcomes included body weight loss, incidence of bile reflux, length of hospital stay, and overall morbidity. We used a random-effects model to conduct meta-analyses. We assessed risk of bias of the included studies in accordance with the Cochrane Handbook for Systematic Reviews of Interventions, and the certainty of the evidence using the GRADE approach. Main results We included eight RCTs (942 participants) in the review. One study included both cancer patients and benign disease patients such as stomach ulcers. Two studies compared Roux-en-Y, Billroth-I, and Billroth-II reconstructions, whilst the other studies compared Roux-en-Y and Billroth-I directly. For the primary outcomes, the evidence suggests that there may be little to no difference in health-related quality of life between Roux-en-Y and Billroth-I reconstruction (standardised mean difference 0.04, 95% confidence interval (CI) -0.11 to 0.18; I² = 0%; 6 studies; 695 participants; low-certainty evidence due to study limitations and imprecision). The evidence for the effect of Roux-en-Y versus Billroth-I reconstruction on the incidence of anastomotic leakage is very uncertain (risk ratio (RR) 0.63, 95% CI 0.16 to 2.53; I² = 0%; 5 studies; 711 participants; very low-certainty evidence). The incidence of anastomotic leakage was 0.6% and 1.4% in the Roux-en-Y and Billroth-I groups, respectively. For the secondary outcomes, the evidence suggests that Billroth-I reconstruction may result in little to no difference in loss of body weight compared to Roux-en-Y reconstruction (mean difference (MD) 0.41, 95% CI -0.77 to 1.59; I² = 0%; 4 studies; 541 participants; low-certainty evidence). Roux-en-Y reconstruction probably reduces the incidence of bile reflux compared to Billroth-I reconstruction (RR 0.40, 95% CI 0.25 to 0.63; I² = 22%; 4 studies; 399 participants; moderate-certainty evidence). Billroth-I reconstruction may shorten postoperative hospital stay, but the evidence for this outcome is very uncertain (MD 0.96, 95% CI 0.16 to 1.76; I² = 56%; 7 studies; 894 participants; very low-certainty evidence). Billroth-I reconstruction may reduce postoperative overall morbidity compared to Roux-en-Y reconstruction (RR 1.47, 95% CI 1.02 to 2.11; I² = 0%; 7 studies; 891 participants; low-certainty evidence). Authors' conclusions The evidence suggests that there is little to no difference between Roux-en-Y and Billroth-I reconstruction for the outcome health-related quality of life. The evidence for the effect of Roux-en-Y versus Billroth-I reconstruction on the incidence of anastomotic leakage is very uncertain as the incidence of this outcome was low. Although the certainty of evidence was low, we found some possibly clinically meaningful differences between Roux-en-Y and Billroth-I reconstruction for short-term outcomes. Roux-en-Y reconstruction probably reduces the incidence of bile reflux into the remnant stomach compared to Billroth-I reconstruction. Billroth-I reconstruction may shorten postoperative hospital stay compared to Roux-en-Y reconstruction, but the evidence is very uncertain. Billroth-I reconstruction may reduce postoperative overall morbidity compared to Roux-en-Y reconstruction. Future trials should include long-term follow-up of health-related quality of life and body weight loss.

Background Accurate preoperative determination of tumor depth is a major concern in colorectal cancer. Assessment of tumor depth can influence the treatment strategy for colorectal cancer, but there is currently no universal diagnostic standard. This review sought to evaluate the diagnostic performance of computed tomography (CT) colonography for tumor infiltration depth in colorectal cancer. Methods The PubMed, Scopus, and Cochrane Central Register of Controlled Trials databases were searched to identify studies that compared the tumor depth using CT colonography with that determined using pathological assessment. Relevant data were extracted from the eligible studies by two review authors working independently. Any disagreement was resolved by discussion. The quality of the studies was assessed using the QUADAS-2 tool. The diagnostic performance of CT colonography for tumor depth in colorectal cancer was evaluated by meta-analysis using sensitivity and specificity values and diagnostic odds ratios. Results The systematic literature search identified 16 eligible studies. The pooled sensitivity and specificity values and diagnostic odds ratios were 97.8% (95% confidence interval [CI] 88.1–99.6), 76.4% (95% CI 59.9–87.5), and 142.6 (95% CI 20.0–1071.0) for T2 invasion, 97.7% (95% CI 92.1–99.3), 83.5% (95% CI 75.9–89.0), and 212.1 (95% CI 50.6–888.1) for T3 invasion, and 84.9% (95% CI 61.7–95.1), 97.5% (95% CI 93.2–99.1), and 219.5 (95% CI 37.8–1273.6) for T4 invasion, respectively. Conclusions CT colonography was found to have high diagnostic performance and was useful for determining tumor depth in colorectal cancer.

Laparoscopic surgery for colorectal cancer has spread globally. The usefulness of laparoscopic surgery for elderly patients was initially indicated by comparison with open surgery. However, whether the procedure is safe for elderly as well as non-elderly patients with colorectal cancer remains unclear. In this review, patients aged ≥ 75 were defined as elderly. We conducted literature searches using PubMed, Scopus, and the Cochrane Central Register of Clinical Trials. Two authors independently reviewed resultant articles to identify relevant observational studies. Data synthesis was performed with a random-effects model. Heterogeneity was investigated by using forest plots and I2 statistics. Risk of bias of included studies was assessed by the Risk of Bias Assessment Tool for Nonrandomized Studies. Publication bias was assessed by funnel plots. Twenty-two studies were included. The incidence of overall complications was slightly higher in elderly patients than in non-elderly patients, with statistical significance (risk ratio (RR) 1.20, 95% confidence interval (CI) 1.08–1.34). There was no difference between them in the incidence of anastomotic leakage (RR 1.24, 95% CI 0.86–1.80) and mortality (risk difference 0.00, 95% CI − 0.01 to 0.01). Laparoscopic surgery for colorectal cancer is mostly safe for elderly patients as well as non-elderly patients. Preoperative comorbidities or poor physical capacity should be cared for in the elderly.

Objectives Prevention of and early treatment for noncommunicable diseases such as hypertension, hyperglycemia, and dyslipidemia are important, as these diseases are asymptomatic in early stages but can lead to critical conditions such as macro‐ and microvascular disorders later on. While screening is conducted worldwide, low rates of hospital visits after screening is a common issue. We aimed to investigate the effect of reminder letters on the consultation behavior of screened participants. Methods We used administrative claims data from a database managed by JMDC Inc for participants of health checkups in 2014, 2015, 2016, and 2017, who belonged to a health insurance society. Reminder letters were sent regularly 6 months after checkups to improve participant consultation behavior. Participants who screened positive for hypertension, hyperglycemia, and dyslipidemia, and who were not taking medication for any of these diseases at the time of health checkups, were included in the analyses. Results A total of 1739 participants in 2014, 1693 in 2015, 2002 in 2016, and 2144 in 2017 were included in the analysis for hypertension. The cumulative proportion of hospital visits gradually increased over the course of 12 months after checkups in all years. After 2015, spikes, albeit very small ones, were observed at 6 months after checkups in accordance with the timing of reminder letters. Similar trends were observed for hyperglycemia and dyslipidemia. Conclusions Sending reminder letters is a potentially effective approach to increase hospital visits, but further improvements (ie, multiple reminders) may be necessary to affect enhancements in participant consultation behavior.

Although the effect of the early detection of colorectal cancer (CRC) on medical costs needs to be clarified, there are few reports on the actual medical costs of CRC patients in Japan. We aimed to identify medical costs according to CRC stage, using health insurance claims. This observational study included CRC patients who had received specific treatment for CRC, which was defined by the procedure code and the claim computer processing system code associated with the treatment of CRC. CRC patients who underwent endoscopic or radical surgical treatment were defined as the curable group and those with palliative treatment, including palliative chemotherapy, as the non-curable group. Total medical costs and medical costs of specific treatments for CRC for 3 years were measured using the claims held by Hachioji City from May 2014 to July 2019. This study included 442 patients in the curable group, including 267 patients who underwent endoscopic treatment, and 175 patients who underwent radical surgical treatment, and 161 patients in the non-curable group. The mean (standard deviation) total medical costs in the curable and non-curable groups were 2,130 (2,494) and 8,279 (5,600) thousand Japanese Yen (JPY), respectively. The mean (standard deviation) medical costs for the specific treatment of CRC in the curable and non-curable groups were 408 (352) and 3,685 (3,479) thousand JPY, respectively. We clarified the actual medical costs of CRC in curable and non-curable groups. These results suggest the effect of early detection of CRC in reducing medical costs.

Background and objectives This prospective study aimed to identify long-term changes in sexual function of men with rectal cancer from point of diagnosis to 24 months postoperatively. Methods Male patients undergoing laparoscopic rectal cancer surgery were prospectively enrolled. International Index of Erectile Function (IIEF) Questionnaire scores were collected at diagnosis; first follow-up; and 6, 12, and 24 months postoperatively. Missing values were managed via multiple imputations using the propensity score method. Paired t tests were applied to examine changes in IIEF scores over time. Results This study analyzed 115 patients. For erectile function, there were no significant changes in scores from the point of diagnosis to first treatment (9.4 vs. 9.8 as mean scores; p = .227). Scores deteriorated postoperatively and recovered until 12 months post-surgery, but did not improve significantly from 12 months to 24 months post-surgery (8.7 vs. 8.2 as mean scores; p = .440). This pattern of change was observed in all other domains: orgasmic function, sexual desire, orgasmic satisfaction, and overall satisfaction. Conclusions Sexual function was not influenced by a rectal cancer diagnosis. Sexual function deteriorated following surgery and recovered until 12 months post-surgery; however, it did not significantly improve from 12 months to 24 months postoperatively.

Objective Additional surgery is considered for patients at high risk for lymph node metastasis (LNM) after local resection for early rectal cancer. Several factors are considered as indications for additional surgery, although there are currently no definitive criteria. This study aimed to clarify the need for additional surgery based on the number of risk factors for LNM and to evaluate the significance of submucosal invasion on recurrence. Methods Patients with early rectal cancer harboring risk factors for LNM who underwent local resection between March 2005 and December 2016 were retrospectively analyzed. Associations among the number of risk factors, prognosis, and additional treatment after local resection were investigated. Results A total of 29 eligible patients were classified into the surgery (n = 10), chemoradiotherapy (n = 7), and no-additional-treatment (NAT, n = 12) groups. Among the 29 patients, 15 patients (52%) with only one risk factor did not relapse. The NAT group harbored fewer risk factors for LNM, and 8 of the 12 patients (67%) had only deep submucosal invasion. Local recurrence occurred in one patient in the chemoradiotherapy group. The estimated 5-year overall survival rates were 88.9%, 75.0%, and 81.5% in the surgery, chemoradiotherapy, and NAT groups, respectively. There were no disease-specific deaths in the overall cohort. Conclusions In the present study, no recurrence occurred in patients who did not receive additional surgery with deep submucosal invasion as the only risk factor. A multicenter investigation is necessary to confirm the safety of nonsurgical options.

Background Emergency gastrointestinal surgery, although rare, is known for its high mortality and morbidity. However, the risks of emergency surgery for gastrointestinal cancer have not been investigated in depth. This study aimed to investigate the impact of emergency surgery on mortality and morbidity in patients with gastrointestinal cancers and to identify associated risk factors. Methods We extracted data from the National Clinical Database, a nationwide surgery registration system in Japan, for patients with gastrointestinal cancer who underwent esophageal resection, total gastrectomy, distal gastrectomy, right hemicolectomy, or low anterior resection between 2012 and 2017. The impacts of emergency surgery on 30‐day mortality and incidence of overall postoperative complications were compared with those of non‐emergency surgery. Risk factors for mortality and overall postoperative complications were then sought in patients who underwent emergency surgery. Results Thirty‐day mortality and incidence of overall postoperative complications were significantly higher in emergency surgeries for gastric, colon, and rectal cancers than in non‐emergency surgeries (odds ratios 4.86‐6.98 and 1.68‐2.18, respectively; all P, This article shows the impact of emergency surgery on mortality and morbidity in patients with gastrointestinal cancers and associated risk factors by using a nationwide registry in Japan. Our findings are expected to serve as a reference for postoperative management.

Aluminum potassium sulfate and tannic acid (ALTA) injection is a new sclerosing therapy for internal hemorrhoids that has been gaining widespread use. However, there have been few reports about rectal cancer after ALTA injection. We performed laparoscopic surgery for three patients who had underwent ALTA therapy 6 months or 1 year earlier: (i) a 51-year-old man with neuroendocrine tumor; (ii) a 44-year-old woman with rectal cancer; and (iii) 77-year-old man with rectal cancer. All three patients had sclerosis of the resected rectal wall stump, making transection of the rectum difficult. Histological examination of the specimens also showed an inflammatory reaction and/or fibrosis of the resection stump. Although laparoscopic low anterior resection was planned for all three patients, we had to construct a diverting stoma for two patients and could not perform sphincter-preserving surgery for the other. We must be well prepared for laparoscopic rectal surgeries after ALTA therapy, and these cases suggest sigmoidoscopy before ALTA therapy should be recommended.

Accurate diagnosis of lateral lymph node metastasis is a major concern in rectal cancer. Metastasis is not only a poor prognostic factor, but it can also affect decisions about treatment options, such as preoperative chemoradiotherapy and lateral lymph node dissection. The purpose of this review was to assess the diagnostic performance of magnetic resonance imaging and computed tomography for lateral lymph node metastasis in rectal cancer. A literature search was systematically performed using PubMed, Scopus, and the Cochrane Central Register of Controlled Trials. All studies in which preoperative magnetic resonance imaging or computed tomography findings involving the lateral lymph nodes were compared with pathologic findings were included. Two authors independently assessed the literature and extracted the data, and any disagreement was resolved by discussion. Pooled sensitivity, specificity, and diagnostic odds ratios were estimated using hierarchical summary receiver-operating characteristic curve analysis. The methodologic quality of the included studies was assessed using the QUADAS-2 tool. Nine studies were included in the meta-analysis of magnetic resonance imaging. The pooled sensitivity, specificity, and diagnostic odds ratio for magnetic resonance imaging were 0.72 [95% confidence interval (CI) 0.66–0.78], 0.80 (95% CI 0.73–0.85), and 10.2 (95% CI 6.4–16.3), respectively. Pooled analyses were not conducted for computed tomography because of the small number of studies (only three could be identified) and the wide range in diagnostic performance between these studies. Magnetic resonance imaging was useful to diagnose lateral lymph node metastasis in rectal cancer, especially due to high specificity.

Background Postoperative paralytic ileus can be a difficult complication for both surgeons and patients. Causes and treatments have been discussed for more than two centuries, but have not yet been fully resolved. Daikenchuto (TJ-100, DKT) is a traditional Japanese herbal medicine. Recently, some beneficial mechanisms of DKT to relieve paralytic ileus have been reported. DKT can suppress inflammation, increase intestinal blood flow, and accelerate bowel movements. Therefore, we have designed a randomized controlled trial to investigate the effects of DKT on postoperative gastrointestinal symptoms following laparoscopic colectomy in patients with left-sided colon cancer at a single institution. Methods/design As primary endpoints, the following outcomes will be evaluated: (i) grade of abdominal pain determined using the numeric rating scale (NRS), (ii) grade of abdominal distention determined using the NRS, and (iii) quality of life determined using the Gastrointestinal Quality Life Index (GIQLI). As secondary endpoints, the following will be evaluated: (i) postoperative nutritional status (Onodera’s Prognostic Nutritional Index (PNI) and the Controlling Nutritional Status score (CONUT score)), (ii) duration to initial flatus, (iii) duration to initial defecation, (iv) bowel gas volume, (v) character of stool (Bristol Stool Form Scale), (vi) defecation frequency per day, (vii) postoperative complications (Clavien-Dindo classification), (viii) length of postoperative hospital stay, and (ix) metabolites in the stool and blood. This trial is an open-label study, and needs to include 40 patients (20 patients per group) and is expected to span 2 years. Discussion To our knowledge, this is the first randomized controlled trial to investigate the effects of DKT on postoperative subjective outcomes (i.e., postoperative quality of life) following laparoscopic colectomy as primary endpoints. Exploratory metabolomics analysis of metabolites in stool and blood will be conducted in this trial, which previously has only been performed in a few human studies. The study aims to guide a future full-scale pragmatic randomized trial to assess the overall effectiveness of DKT to improve the postoperative quality of life following laparoscopic colectomy. Trial registration UMIN-CTR (Japan), UMIN000023318. Registered on 25 July 2016. Electronic supplementary material The online version of this article (doi:10.1186/s13063-017-2307-7) contains supplementary material, which is available to authorized users.