The programmed death‐1/programmed death‐ligand 1 (PD‐L1) pathway is a negative feedback pathway that suppresses the activity of T cells. Previous studies reported that high PD‐L1 expression on tumor cells (TC) was associated with poor survival in patients with colorectal cancer; however, the prognostic evaluation of these studies was limited because they included patients at various disease stages. The purpose of the present study was to evaluate the relationship between PD‐L1 status in the immune microenvironment and the clinicopathological features of stage III colorectal cancer. Two hundred and thirty‐five patients were included in the analysis. PD‐L1 expression on TC and tumor‐infiltrating mononuclear cells (TIMC) was evaluated by immunohistochemistry. The median follow‐up of thisi study was 52.9 months. A total of 8.1% of stage III colorectal cancer showed high PD‐L1 expression on TC and 15.3% showed high PD‐L1 expression on TIMC. Patients with high PD‐L1 expression on TC had significantly shorter disease‐free survival (DFS) than patients with low expression (hazard ratio [HR] 2.36; 95% confidence interval [CI], 1.21–4.62; P = 0.012). In addition, patients with high PD‐L1 expression on TIMC were associated with longer DFS than patients with low expression (HR 0.40; 95% CI, 0.16–0.98; P = 0.046). These findings suggest that PD‐L1 expression status may be a new predictor of recurrence for stage III colorectal cancer patients and highlight the necessity of evaluating PD‐L1 expression on TC and TIMC separately in the tumor microenvironment.

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Objectives: Colonic diverticular disease is widespread in Western countries and its associated with aging. In Japan, diverticulitis and colovesical fistula are also occurring more frequently. Colonic resection for diverticula-related fistulas is frequently technically demanding because of associated acute or chronic inflammation. We evaluated the safety and efficacy of a standardized laparoscopic procedure. Methods: Data from 39 consecutive patients who had undergone laparoscopic surgery for colovesical fistula between October 2006 and August 2017 were retrospectively reviewed. Results: The patients' median age was 60 years and comprised 35 men and four women. Sigmoidectomy was performed in 33 patients, Hartmann's procedure in four, and anterior resection in two. The median operative time was 203 minutes and estimated blood loss 15 mL. There were no intraoperative complications or conversion to open surgery. No patients required bladder repair; three had minor postoperative complications, and none had recurrent diverticulitis or fistula at a mean follow-up of 5.1 years. Conclusions: The magnified vision and minimal invasiveness make a laparoscopic approach the ideal means of managing colovesical fistula. To our knowledge, this is the largest study of colovesical fistula managed by a standardized laparoscopic procedure.

Background There is a lack of large studies focusing on the prognostic significance of lateral lymph node (LLN) metastasis following LLN dissection (LLND) in rectal cancer. The aim of this study was to evaluate the prognostic impact of LLN metastases on survival of patients with advanced low rectal cancer. Methods Consecutive patients with locally advanced, but not metastatic, extraperitoneal rectal cancer treated with neoadjuvant (chemo)radiotherapy plus total mesorectal excision between 2004 and 2015 were included in the study. LLND was performed when pretreatment imaging documented enlarged LLNs (7 mm or greater in size). Localization of nodal metastases and long‐term outcomes were analysed. Kaplan–Meier analysis was used to compare the survival of patients with ypN0 disease with that of patients with mesorectal ypN+/LLN− status and patients with positive LLNs. The Cox proportional hazards model was used to evaluate predictors of disease‐free survival (DFS) and local recurrence. Results A total of 613 patients were included in the study; LLND was performed in 212 patients (34·6 per cent) and 57 (9·3 per cent) had LLN metastasis. Patients with LLN metastasis had improved DFS and local recurrence cumulative incidence rates compared with patients with mesorectal ypN2+/LLN− disease (DFS: P = 0·014; local recurrence: P = 0·006). Although the DFS rate of patients with LLN metastasis was worse than that of patients with ypN0 disease (P < 0·001), the cumulative incidence of local recurrence was similar (P = 0·491). In multivariable analysis, residual LLN metastasis was not an independent predictor of worse DFS or local recurrence. Conclusion LLN metastasis is not an independent predictor of local recurrence or survival. Survival of patients presenting with LLN metastasis after (chemo)radiotherapy was intermediate between that of patients with ypN0 status and those with mesorectal ypN2 positivity.

Background: Ischemic colitis can occur after colectomy and is sometimes difficult to treat. We report 4 cases of refractory, delayed onset, regional congestive colitis occurring on the anal side of the anastomosis after laparoscopic left hemicolectomy. Case presentation: A total of 191 patients underwent surgery for left colon cancer (transverse, descending, and sigmoid colon cancer) at our hospital from January 2012 to December 2017. During the procedures, the left colic artery (LCA) or sigmoid colic artery (SA) was dissected, the superior rectal artery (SRA) was preserved, and the inferior mesenteric vein (IMV) was dissected at the inferior margin of the pancreas. Congestive ischemic colitis due to venous return dysfunction occurred in 4 cases (2.1%), 5 to 34 months postoperatively. The patients had diarrhea and blood in the stool. On computed tomography (CT), the patients exhibited continuous intestinal edema and high-density adipose tissue from the anastomosis site to the rectum. Contrast enhancement showed dilation of the vasa recti and arteries from the inferior mesenteric artery (IMA) to the SRA. Three patients improved with long-term intestinal rest; in 1 case, the stenosis did not improve and required colorectal resection. Conclusion: Diagnoses were easy in these cases, but treatment was prolonged and surgery was necessary in 1 case. While this condition is rare, caution is warranted as it is difficult to treat.