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