Risk of peritoneal recurrence following laparoscopic versus open surgery for stage II/III colorectal cancer: An integrated analysis of three Phase III randomized controlled trials (JCOG2310AS2).

[INTRODUCTION] The risk of peritoneal recurrence following LAP remains unclear because of inconsistent data and a limited number of recurrence events. The objective of this study is to evaluate whether laparoscopic surgery (LAP) is a potential risk factor for peritoneal recurrence following curative surgery for stage II/III colorectal cancer (CRC).

[MATERIALS AND METHODS] Data from three Phase III trials were extracted from an ancillary research database (JCOG2310A). Patients with pStage II/III CRC who underwent curative surgery were identified and included in this study. The frequency of peritoneal recurrence was compared between the LAP and open surgery (OP) groups. Multivariable analysis was performed to adjust for covariates between the groups. The primary outcome was the cumulative incidence of peritoneal recurrence. The secondary outcome was the cumulative incidence in high-risk subgroups identified by multivariable analysis.

[RESULTS] Data for 3061 eligible patients were included (OP group, n = 1734; LAP group, n = 1327). During a median follow-up of 6.2 years, the 5-year cumulative incidence of peritoneal recurrence was 2.8 % (95 % CI 2.1-3.6) in the OP group and 2.9 % (95 % CI 2.1-3.9) in the LAP group (adjusted HR 1.086, 95 % CI 0.683-1.727). Multivariable analysis identified pT4, pStage III, an ECOG performance status of 1, and a right-sided tumor as risk factors for peritoneal recurrence. There was no significant difference in the peritoneal recurrence rate between OP and LAP in these subgroups.

[CONCLUSION] This integrated analysis found that LAP was not a risk factor for peritoneal recurrence following curative surgery for stage II/III CRC.