Long-term results of "selective sandwich" adjunctive radiotherapy for cancer of the rectum.

A total of 132 patients with adenocarcinoma of the rectum were treated in a program of "selective sandwich" adjunctive radiation therapy and have been followed for a minimum period of 5 years. All patients were given a single dose of preoperative radiation, 500 cGy, either on the day of or the day before surgery. At surgery, 12 patients with metastatic disease were treated palliatively. The remaining 120 patients underwent radical curative surgery. Patients were then staged histopathologically according to the Astler-Coller modification of Dukes' staging: 34 patients with stage A or B1 disease were followed with no further treatment; 54 patients with stage B2 or C cancer received a planned course of high-dose postoperative radiation (4,500 cGy in 5 weeks); 32 patients with stage B2 and C cancer received no further treatment. Radiation therapy was well tolerated with few long-term side effects. None of the patients receiving low-dose preoperative radiation alone had any complications. Two patients (4%) treated with the combined pre- and postoperative radiation experienced major small bowel complications. Local recurrence was observed in 11 of 32 patients (34%) with stage B2 and C disease receiving low-dose preoperative radiation alone, as compared to 5 of 54 patients (9%) of the combined pre- and postoperative radiation group. The absolute 5-year survival in these two groups is 54% and 72%, respectively. With follow-up now exceeding 5 years, the survival of patients treated with the planned approach of combined pre- and postoperative radiation continues to remain appreciably better than for patients receiving low-dose preoperative radiation alone.