Long-term oncologic outcomes after laparoscopic vs. open colon cancer resection: a high-quality population-based analysis in a Southern German district

BACKGROUND: Over 20 years after the introduction of laparoscopic surgery for colon cancer, many surgeons still prefer the open approach. Whereas randomized controlled trials (RCTs) have proven the oncologic safety of laparoscopy, long-term data depicting daily clinical routine are scarce. METHODS: This population-based cohort study compares 5-year overall, relative, and recurrence-free survival rates after laparoscopic and open colon carcinoma surgery. Data derive from an independent German cancer registry encompassing all tumor patients within a political district of 1.1 million inhabitants. The final analysis included 2669 patients with major elective resection of primary non-metastatic colonic adenocarcinoma between January 1, 2004 and December 31, 2013. Survival rates were compared using Kaplan–Meier analyses, relative survival models, and multivariate Cox regression. Sensitivity analysis quantified selection bias. RESULTS: The proportion of laparoscopic procedures increased from 9.7 to 25.8% in 2011 and dropped again to 15.8% at the end of observation period. Laparoscopy patients were younger, had a lower tumor stage, and were more likely to receive postoperative chemotherapy. Overall, relative, and recurrence-free survival was significantly superior or equivalent in Kaplan–Meier analysis (5-year overall survival rate open vs. laparoscopic: 69.0 vs. 80.2%, p < 0.001). The superiority of laparoscopy mostly remained stable after adjusting for confounders, although significance was only reached in T1-3 patients without lymph node metastases (overall survival: hazard ratio (HR) 0.654; 95% confidence interval (CI) 0.446–0.958; p = 0.029). CONCLUSION: Laparoscopy is a safe and promising alternative to the open approach in daily clinic practice. These favorable outcomes require future confirmation by high-quality studies outside the setting of RTCs.