Survival following moderate-dose preoperative radiation therapy for carcinoma of the rectum

We performed a retrospective study of patients with carcinoma of the rectum or rectosigmoid undergoing surgical resection. Forty-two patients received adjuvant preoperative radiation therapy (4000-4500 rad). One hundred twenty patients underwent surgical resection alone. Survival of radiation patients was significantly improved over that of Surgery Only patients, even after adjusting for nontreatment factors using Cox regression. Crude 5-year survival was 63% for radiation patients (74% adjusted) compared to 46% for surgery-only patients (48% adjusted) (P less than 0.025). Radiation patients also had longer disease-free survival than surgery-only patients (P less than 0.05) and fewer recurrences (14% versus 37%; P less than 0.025). Fewer radiation patients had lymph nodes involved with tumor than surgery-only patients (20% versus 35%; P = 0.07). Although 71% of radiation patients experienced radiation reactions, these were primarily mild and transitory. We believe that preoperative radiation is an effective and safe adjunct to surgery in the treatment of rectal cancer and that its use can lead to improved survival rates.