Propensity Score Analysis in the Comparison of Long-Term Outcomes for Locally Advanced Colon Cancer Between Laparoscopic Colectomy and Open Colectomy

Abstract

Objective: It is difficult to conduct a randomised control trial in a single institution because of the small number of cases. The current study was conducted to investigate if there is any difference in long-term outcome between laparoscopic surgery (LAC) and open surgery (OC) using propensity-score matching analysis based on prognostic factors.

Materials: Two hundred and sixteen patients with locally-advanced colon cancer who underwent surgery with curative intent at our department between 2002 and 2010 were enrolled in the current study.

Methods: Propensity score matching analysis and Inverse Probability Weighting (IPW) estimator were used to adjust for differences in the clinicopathological severity between LAC and OC.

Results: Before propensity score matching analysis recurrence-free survival in LAC was statistically better than that in OC (Hazard ratio= 0.59, 95% CI 0.35-0.98, p=0.04), and no statistically significant difference was recognized for cancer-specific survival (Hazard ratio=0.63, 95% CI 0.27-1.37, p=0.25). After propensity score matching analysis there were no statistically significant differences for recurrence-free (Hazard ratio=0.91, 95% CI 0.41-2.01, p=0.81) or cancer-specific survival (Hazard ratio=1.38, 95% CI 0.41-4.82, p=0.59). In addition, the IPW estimator revealed that the difference for recurrence-free survival was not significant between the two groups.

Conclusion: The one-to-one pair propensity score matching successfully balanced the clinicopathological factors between LAC and OC. The propensity score matching analysis demonstrated no significant difference between LAC and OC.