Laparoscopic surgery facilitates administration of adjuvant chemotherapy in locally advanced colon cancer: propensity score analyses

Purpose: The aim of this study was to evaluate the impact of a laparoscopic approach on long-term oncological outcomes in curative intent surgery for pT4 colon cancer, in both overall and stratified subgroups with distinct clinical entities. Patients and methods: Patients with a pT4N0-2M0 colon cancer from four centers between 2000 and 2014 were included. Laparoscopic and open approaches were compared according to the intention-to-treat principle. Propensity scores were used to adjust for baseline differences between the groups in three manners: i) as a linear predictor in a Cox regression model, ii) to create a 1:1 matched cohort, and iii) to stratify patients into four groups with an increasing chance of receiving laparoscopy. Results: In total, 424 patients were included. After 1:1 matching, a laparoscopic approach correlated with higher rates of radical resection, lower morbidity, and a higher percentage of patients receiving adjuvant chemotherapy. This translated into better 5-year disease-free survival (52% vs 40%, HR 0.70; 95% CI 0.50–0.96) and 5-year overall survival (68% vs 57%, HR 0.66; 95% CI 0.43–0.99). These results were confirmed in the other two propensity score analyses. In the multivariable models, adjuvant chemotherapy remained independently associated with better survival, whereas surgical approach lost significance. Conclusions: In locally advanced colon cancer, an intentional laparoscopic approach in experienced hands seems to decrease morbidity and to increase the proportion of patients receiving adjuvant chemotherapy. Receiving adjuvant chemotherapy was independently associated with improved survival.