Yutaka Hanaoka

Prognostic value of Programmed death-ligand 1 expression in patients with stage III colorectal cancer

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.

Can laparoscopic appendectomy be safely performed by surgical residents without prior experience of open appendectomy

BACKGROUND As laparoscopic surgery has become the mainstream technique for abdominal surgery, it has become difficult for surgical residents to have opportunities to perform open surgery. This study aimed to examine the appropriateness and feasibility of laparoscopic appendectomy performed by surgical trainees who had little experience with open appendectomy or laparoscopic training with animal models. METHODS We retrospectively reviewed all the records of patients who underwent appendectomy for acute appendicitis from April 2008 to December 2014. Residents were assigned to two levels of seniority: junior residents who had undergone 1-3 years of residency and senior residents who had undergone 4-6 years of residency. Patient characteristics, histopathological results, operative time, blood loss, conversion to open procedure, complications, length of hospital stay, and mortality were compared between the two groups. RESULTS During the study period, 174 patients with the clinical diagnosis of acute appendicitis underwent laparoscopic appendectomy by junior residents and 90 patients were operated on by senior residents. There were no statistical differences in the characteristics of the patients, conversion rates (0/174 vs. 1/90), median operative times (75 minutes vs. 75 minutes), complication rates (7% vs. 4%), and median lengths of hospital stay (4 days vs. 4 days). CONCLUSION Laparoscopic appendectomy can be performed safely by surgical residents who had little experience or training with animal models or open appendectomy. In this era of laparoscopic surgery, laparoscopic appendectomy represents an important opportunity for training surgical residents with little experience of open surgery.

Successful laparoscopic ligation for massive chylous ascites after rectal cancer surgery

A 53‐year‐old man was readmitted with abdominal distention 2 weeks after undergoing laparoscopic low anterior resection with para‐aortic lymphadenectomy for advanced rectal cancer (T4aN1M0, Stage IIIb). Ultrasound revealed massive ascites, and paracentesis revealed chylous fluid with a markedly elevated triglyceride level (1762 mg/dL). Despite conservative management, the fistula remained on postoperative day 120. On percutaneous lymphangiography, the chylous leakage point was clearly visualized at the para‐aortic site, and surgical intervention was planned. The abdominal cavity was carefully explored with laparoscopy, and the lymphatic leakage point was detected at the site of previous lymphadenectomy. Leakage was stopped with direct suture ligation and fibrin glue, and the patient was discharged 2 weeks later with no recurrence of the chylous fistula. Surgical intervention can be effective in select patients with a major chylous fistula that persists despite conservative therapy. When the leakage point is localized and detectable on percutaneous lymphangiography, the laparoscopic approach may be feasible.

Curative resection for locally advanced sigmoid colon cancer using neoadjuvant chemotherapy with FOLFOX plus panitumumab: A case report

Highlights • Systemic or adjuvant chemotherapy is internationally accepted as a standard treatment for patients with metastatic or postoperative colorectal cancer, respectively.• Moreover, recent studies have demonstrated that preoperative chemotherapy improves the outcome of patients with CRC with liver metastases.• However, little is known about the effect and safety of preoperative FOLFOX and panitumumab combined chemotherapy for initially unresectable, locally advanced colon cancer without distant metastases.

Prognostic significance of programmed death-ligand 1 (PD-L1) expression on tumor infiltrating immune cells (IC) in patients with stage IIIb colorectal cancer.

611 Background: Programmed death 1 (PD-1)/ PD-L1 pathway is a negative feedback mechanism that suppresses the activity of T cells. Some previous studies showed that positive PD-L1 expression on tumor cells (TC) was poor prognostic factor in patients with colorectal cancer; however, recent studies suggest that IC also play important roles to determine the prognosis in cancer patients. The aim of this study is to investigate the association of clinical and pathological features with PD-L1 expression on TC and IC. Methods: We retrospectively reviewed data of consecutive patients with stage IIIb colorectal cancer (Japanese classification of colorectal carcinoma The 8th Edition), who underwent surgery and received adjuvant chemotherapy in our institution between January 2009 and July 2012. PD-L1 expression was evaluated by immunohistochemistry (IHC) on TC and IC. Specimens were scored as IHC low (L) or high (H), if < 5% or ≥ 5% of cells were PD-L1 positive, respectively. Results: Seventy-four patients were inc...