Laparoscopic approach for T4 colon cancer can be associated with poor prognosis in right-sided T4b tumours.

INTRODUCTION: Although recent studies have demonstrated the safety of laparoscopic surgery in T4 colon cancer, some patients could have poor prognosis. In this study, we aimed to analyse the risk factors affecting oncologic outcome of laparoscopic surgery. MATERIALS AND METHODS: Among the 1033 T4 colon cancer patients collected from a multicentre database (2004-2017), 584 patients (458 T4a and 126 T4b) underwent laparoscopic approach for radical surgery. Risk factors associated with 3-year disease-free survival (DFS) and overall survival (OS) were evaluated through multivariate analysis. In addition, subgroups were classified using a combination of risk factors, and the survival rate was evaluated. RESULTS: During this period, 188 (32.2%) had recurrence, and 151 (25.9%) died. In the multivariate analysis for oncologic outcome, elevated carcinoembryonic antigen level (hazard ratio [HR] 1.37) and absence of adjuvant chemotherapy (HR 1.60) were associated with poor DFS. T4b (HR 1.56, 1.46), right-sided location (HR 1.52, 1.42), and open conversion (HR 2.70, 2.12) were independently associated with both poor DFS and OS. When four subgroups were analysed through the combination of tumour location and T stage, the DFS and OS rates were significantly lower in patients with right-sided T4b cancer than in other groups (log-rank p < 0.001). CONCLUSION: Right-sided T4b colon cancer for laparoscopic surgery may lead to poor oncologic outcome. This approach could be a caution in suspected cases preoperatively.