Total mesorectal excision with or without preoperative chemoradiotherapy for resectable mid/low rectal cancer: a long-term analysis of a prospective, single-center, randomized trial

Background: The preliminary results of our phase II randomized trial reported comparable functional sphincter preservation rates and short-term survival outcomes between patients undergoing total mesorectal excision (TME) with or without preoperative concurrent chemoradiotherapy (CCRT). We now report the long-term results after a median follow-up of 71 months.

Methods: Between March 23, 2008 and August 2, 2012, 192 patients with T3-T4 or node-positive, resectable, mid/low rectal adenocarcinoma were randomly assigned to receive TME with or without preoperative CCRT. The following endpoints were assessed: cumulative rates of local recurrence and distant metastasis, disease-free survival (DFS), and overall survival (OS).

Results: The data of 184 eligible patients were analyzed: 94 patients in the TME group and 90 patients in the CCRT + TME group. In the whole cohort, the 5-year DFS and OS rates were 84.8% and 85.1%, respectively. The 5-year DFS rates were 85.2% in the CCRT + TME group and 84.3% in the TME group (P = 0.969), and the 5-year OS rates were 83.5% in the CCRT + TME group and 86.5% in the TME group (P = 0.719). The 5-year cumulative rates of local recurrence were 6.3% and 5.0% (P = 0.681), and the 5-year cumulative rates of distant metastasis were 15.0% and 15.7% (P = 0.881) in the CCRT + TME and TME groups, respectively. No significant improvements in 5-year DFS and OS were observed with CCRT by subgroup analyses.

Conclusions: Both treatment strategies yielded similar long-term outcomes. A selective policy towards preoperative CCRT is thus recommended for rectal cancer patients if high-quality TME surgery and enhanced chemotherapy can be performed. Trial registration ChiCTR-TRC-08000122. Registered 16 July 2008.