A multicenter, propensity score-matched cohort study about short-term and long-term outcomes after laparoscopic versus open surgery for locally advanced rectal cancer.

PURPOSE: This study evaluated the results of laparoscopic surgery (LAP) compared to open surgery (OP) for locally advanced mid-to-lower rectal cancer. METHODS: From February 2008 to December 2014, we collected patient data with clinical stage II/III mid-to-lower rectal cancer who underwent resection with LAP or OP at 13 institutions associated with the Yokohama Clinical Oncology Group (YCOG). The short-term outcomes and long-term prognoses associated with LAP and OP were analyzed after adjusting for the patients' backgrounds using propensity score matching. RESULTS: Among 1091 eligible cases, a propensity score matching with six covariates-age, sex, body mass index, American Society of Anesthesiologists physical status category, tumor location, and clinical stage-extracted 237 cases each for the LAP and OP groups, respectively. After matching, there were no differences in background factors between the two groups except for the presence or absence of preoperative treatment. Operative time was significantly longer in the LAP group than that in the OP group (p < 0.001), while the amount of bleeding and the length of postoperative hospital stay were significantly lower in the LAP group than that in the OP group (p < 0.001 and p = 0.001, respectively). There were no significant differences between groups in the incidence of postoperative complications. The 3-year overall survival and relapse-free survival rates were 90.5% and 88.6% and 78.3% and 71.6% in the LAP and OP groups, respectively, which did not differ significantly. CONCLUSIONS: The short-term outcomes and long-term prognoses of LAP in this cohort study indicated that LAP could be a therapeutic option for locally advanced rectal cancer. TRIAL REGISTRATION: UMIN000040406.