STAGE-TO-STAGE COMPARISON OF PREOPERATIVE AND POSTOPERATIVE CHEMORADIOTHERAPY FOR T3 MID OR DISTAL RECTAL CANCER

Abstract

Purpose: To investigate, in a comparative analysis, the prognostic implications of postchemoradiotherapy (post-CRT) pathologic stage (ypStage) vs. postoperative pathologic stage (pStage) in rectal cancer. Methods and Materials: Between May 2001 and December 2006, 487 patients with T3 mid or distal rectal cancer were analyzed retrospectively. Concurrent CRT was administered preoperatively (n = 364, 74.7%) or postoperatively (n = 123, 25.3%). The radiation dose was 50.4 Gy in 28 fractions. All patients underwent a total mesorectal excision and received adjuvant chemotherapy. Disease-free survival (DES) was estimated using the Kaplan-Meier method. Differences in DFS, stratified by ypStage and pStage, were compared using the log rank test. Results: For surviving patients, the median follow-up period was 68 months (range, 12-105 months). The 5-year local recurrence-free survival rate was not different, at 95.3% and 92.1% in preoperative and postoperative CRT groups, respectively (p = 0.402), but the 5-year distant metastasis-free survival rate was significantly different, at 81.6% (preoperative CRT) vs. 65.4% (postoperative CRT; p = 0.001). The 5-year DFS rate of 78.8% in the preoperative CRT group was significantly better than the 63.0% rate in the postoperative CRT group (p = 0.002). Post-CRT pathologic Stage 0-I occurred in 42.6% (155 of 364) of the patients with preoperative CRT. The 5 year DFS rates were 90.2% (ypStage 0-I), 83.5% (ypStage II), 77.3% (pStage H), 58.6% (ypStage HI), and 54.7% (pStage III). The DES rate of ypStage 0-I was significantly better than that of ypStage H or pStage II. Post-CRT pathologic Stage H and III had similar DFS, compared with pStage II and III, respectively. Conclusions: Disease-free survival predicted by each ypStage was similar to that predicted by the respective pStage. Improved DFS with preoperative vs. postoperative CRT was associated with the ypStage 0 I group that showed a similarly favorable outcome to pStage I rectal cancer. (C) 2012 Elsevier Inc.