Minimally Invasive Surgery for Rectal Adenocarcinoma Shows Promising Outcomes Compared to Laparotomy, a National Cancer Database Observational Analysis

Purpose/Background: The surgical approach to adenocarcinoma of the rectum remains a controversial topic. Although current data focus on the noninferiority of minimally invasive surgery (MIS) for rectal cancer compared with laparotomy, conclusions are drawn from smaller sample sizes and may be underpowered. Methods/Interventions: The National Cancer Database (NCDB) from 2010 to 2014 was reviewed for all cases of invasive adenocarcinoma of the rectum (SEER Histology Codes 8140) who underwent surgical resection for malignancy. Groups were separated based on laparotomy or an MIS approach and stratified by NCDB Analytic Stage. Multivariate Cox regression analysis was used to evaluate for survival after diagnosis of adenocarcinoma of the rectum. Results/Outcomes: The inclusion criteria identified 29,199 cases of adenocarcinoma of the rectum managed surgically. After controlling for differences in the cohorts, survival after diagnosis and definitive surgical treatment for adenocarcinoma of the rectum is improved when an MIS approach was used (adjusted hazard ratio [HR]=0.82, 95% confidence interval [CI]=0.77-0.88, P<.001). The protective effect of an MIS approach applied to Stages I, II, III, and IV adenocarcinoma of the rectum. The protective effect of a minimally invasive surgical approach applies to Stages I, II, III, and IV adenocarcinoma of the rectum. The rate of negative circumferential margins (86.2% versus 83.5%, P<.001), proximal and distal margins (94.7% versus 92.1%, P<.001), and lymph node yield >12 (73.2% versus 70.1%, P<.001) was higher in the minimally invasive group compared with laparotomy. The intraoperative conversion rate from MIS to laparotomy was 13.9%. Conclusion/Discussion: Minimally invasive resection for adenocarcinoma of the rectum shows promising survival benefit compared with open surgery after adjusting for measured confounds.