Combined modality therapy of resectable high risk rectal cancer.

Aim of this phase I-II study was to evaluate the efficacy of preoperative concomitant radiochemotherapy in resectable high risk (TNM stage: II and III) rectal tumors, 64 patients entered the study: 37 had low rectal cancer, 27 mid-rectal cancer. 50 patients were clinically staged as stage III (Dukes C) and 14 as stage II (Dukes B). Treatment protocol included bolus mitomycin C at the dose of 10 mg/m2 on day 1 and 5FU continuous infusion at the daily dose of 1000 mg/m2 on day 1, 2, 3, 4. Concomitant external radiotherapy up to a dose of 3780 cGy was delivered at the daily dose of 180 cGy. Surgery was performed 4 to 5 weeks after radiation therapy (RT). Before surgery all patients were clinically restaged to evaluate the response to concomitant radiochemotherapy. Treatment compliance was 97%. Toxicity was 27% prevalently shown as bone marrow depletion and radiodermatitis. In 37 patients (61%) there was 50% reduction (partial response) of neoplastic volume. In 5 patients (8%) no neoplastic cells were evidenced in the surgical specimen on histology (complete response). The distance between the lower margin of the tumor and the internal anal orifice increased in 72% of cases. Postoperative morbidity was 28%. The incidence of anastomotic dehiscences was 8.7% over 46 anterior resections. Postoperative mortality was nil. Definitive staging evidenced 24 patients (39%) stage I or with no evidence of tumor. The incidence of local recurrence was 5% and that of distant metastasis 8%.