Defining the Role of Minimally Invasive Proctectomy for Locally Advanced Rectal Adenocarcinoma

Objective: National examination of open proctectomy (OP), laparoscopic proctectomy (LP), and robotic proctectomy (RP) in pathological outcomes and overall survival (OS). Background: Surgical management for rectal adenocarcinoma is evolving towards utilization of LP and RP. However, the oncological impacts of a minimally invasive approach to rectal cancer have yet to be defined. Methods: Retrospective review of the National Cancer Database identified patients with nonmetastatic locally advanced rectal adenocarcinoma from 2010 to 2014, who underwent neoadjuvant chemoradiation, surgical resection, and adjuvant therapy. Cases were stratified by surgical approach. Multivariate analysis was used to compare pathological outcomes. Cox proportional-hazard modeling and Kaplan-Meier analyses were used to estimate long-term OS. Results: Of 6313 cases identified, 53.8% underwent OP, 31.8% underwent LP, and 14.3% underwent RP. Higher-volume academic/research and comprehensive community centers combined to perform 80% of laparoscopic cases and 83% of robotic cases. In an intent-to-treat model, multivariate analysis demonstrated superior circumferential margin negativity rates with LP compared with OP (odds ratio 1.34, 95% confidence interval 1.02-1.77, P = 0.036). Cox proportional-hazard modeling demonstrated a lower death hazard ratio for LP compared with OP (hazard ratio 0.81, 95% confidence interval 0.67-0.99, P = 0.037). Kaplan-Meier analysis demonstrated a 5year OS of 81% in LP compared with 78% in RP and 76% in OP (P = 0.0198). Conclusion: In the hands of experienced colorectal specialists treating selected patients, LP may be a valuable operative technique that is associated with oncological benefits. Further exploration of pathological outcomes and long-term survival by means of prospective randomized trials may offer more definitive conclusions regarding comparisons of open and minimally invasive technique.