Preoperative chemoradiotherapy for clinically diagnosed T3N0 rectal cancer.

Abstract

This retrospective study compared the recurrence-free survival (RFS) and local recurrence rates of patients who received preoperative chemoradiotherapy (PCRT) for cT3N0 vs. those who did not. We analyzed the records of 593 patients with transrectal ultrasound (TUS) or magnetic resonance image (MRI)-staged cT3N0 mid and low locally advanced rectal cancer, including 255 who received PCRT and 338 who did not. The RFS and cumulative local recurrence rates were compared in the two groups. We also investigated the rates of pathologic complete response (pCR) and mesorectal lymph node (LN) involvement in the PCRT group. The overall pCR rate was 13.3%. Of the 338 non-PCRT patients, 125 (37.0%) had pathologically positive mesorectal LNs. Sphincter-preserving surgery was performed in 431 (72.7%) of the 593 patients, with similar rates in the two groups. However, the sphincter preservation rate in patients with low rectal cancer was higher among those who received PCRT than among those who did not (64.8 vs. 47%, P=0.002). The 5-year RFS (76.4 vs. 75.5%, P=0.92) and local recurrence (3.9 vs. 3.0%, P=0.97) rates were similar in the PCRT and non-PCRT groups. Although PCRT did not improve the RFS or local recurrence rates, it increased the chance of sphincter preservation in patients with low rectal cancer. The advantages of PCRT for patients with cT3N0 should be re-evaluated considering the limitation of pretreatment staging, oncologic benefits, and improved sphincter preservation.