Long-term Outcomes of Laparoscopic Versus Open D3 Dissection for Stage II/III Colon Cancer: Results of Propensity Score Analyses

Background: Non-inferiority of the laparoscopic approach for stage II/III colon cancer has not been clearly established. This study aimed to evaluate the long-term outcomes of laparoscopic versus open D3 surgery.

Methods: Subjects were 1230 consecutive patients with stage II/III colon cancer, who were referred to the National Cancer Center Hospital from 2004 to 2013. Open surgery was performed in 821 (67%) patients, and laparoscopic surgery was performed in 409 (33%). Propensity score analyses with overall survival as the primary endpoint were performed in three different propensity score methods.

Results: Regression adjustment using the propensity score as a linear predictor in the model showed similar overall survival between laparoscopic and open surgeries [hazard ratio (HR), 0.98 (95% CI [0.64-1.46]; p = 0.916)]. Stratification analysis of the entire cohort revealed that, among five strata, only the highest stratum (clinical T2/T3, clinical N0/N1, tumor size <6 cm, and body mass index (BMI) < 28) had an HR of <1 (0.37). In the other four strata, open surgery was favored as reflected by HRs of >1 (1.13-1.26). The propensity score-matched cohort (365 matched pairs), from which patients with advanced disease and high BMI were excluded, yielded an HR of 0.93 (95% CI [0.57-1.52]; p = 0.772).

Conclusions: Laparoscopic surgery appeared to be a safe and reasonable option for patients with stage II/III colon cancer in general. Patients with high BMI, clinical N2 and T4 disease, and tumor size ≥6 cm might require prudent selection of surgical approach.