[Preoperative chemoradiotherapy for adenocarcinoma of the rectum: current outcomes and perspectives]

Preoperative chemoradiotherapy reduces local recurrence in patients with locally advanced adenocarcinoma of the rectum. We treated 157 patients with combination therapy consisting of preoperative radiation with 20 Gy and intraoperative electron beam radiation with 15 Gy, and treated 147 patients with preoperative radiation of a total dose of 45 Gy and concomitant chemotherapy with oral UFT or TS-1. These 304 patients were named RT group. We compared the outcomes of RT group with those of 112 patients treated with surgery alone including lateral pelvic lymph nodes dissection (S group). Both DFS and OS were significantly better in RT group than S group (p = 0.0002, p = 0.002). Local failure rate was 17% in S group and 2% in RT group (p < 0.0001). Patients with downstaging or good histologic response after CRT revealed significantly better DFS and OS. However, patients without downstaging or histologic response revealed worse prognosis. Appropriate adjuvant chemotherapy is needed for these patients.