An observational study of patho-oncological outcomes of various surgical methods in total mesorectal excision for rectal cancer: a single center analysis

BACKGROUND: Total mesorectal excision (TME) with or without neoadjuvant concurrent chemoradiotherapy (CCRT) is the treatment for rectal cancer (RC). Recently, the use of conventional laparoscopic surgery (LS) or robotic-assisted surgery (RS) has been on a steady increase cases. However, various oncological outcomes from different surgical approaches are still under investigation. METHODS: This is a retrospective observational study comprising 300 consecutive RC patients who underwent various techniques of TME (RS, n = 88; LS, n = 37; Open surgery, n = 175) at a single center of real world data to compare the pathological and oncological outcomes, with a median follow-up of 48 months. RESULTS: Upon multivariate analysis, histologic grade (P = 0.016), and stage (P < 0.001) were the independent factors of circumferential resection margin (CRM) involvement. The Kaplan-Meier survival analysis determined RS, early pathologic stage, negative CRM involvement, and pathologic complete response to be significantly associated with better overall survival (OS) and disease-free survival (DFS) (all P < 0.05). Multivariable analyses observed the surgical method (P = 0.037), histologic grade (P = 0.006), and CRM involvement (P = 0.043) were the independent factors of DFS, whereas histologic grade (P = 0.011) and pathologic stage (P = 0.022) were the independent prognostic variables of OS. CONCLUSIONS: This study determined that RS TME is feasible because it has less CRM involvement and better oncological outcomes than the alternatives have. The significant factors influencing CRM and prognosis depended on the histologic grade, tumor depth, and pre-operative CCRT. RS might be an acceptable option owing to the favorable oncological outcomes for patients with RC undergoing TME.