[Adjuvant radio-chemotherapy in cancer of the rectum treated with radical surgery and with high risk of recurrence. Preliminary results of a prospective study].

UNLABELLED: INTRODUCTION MATERIAL AND METHODS: From January, 1990, to December, 1995, 138 consecutive patients with radically resected stage II and III rectal and rectosigmoid cancers were treated with adjuvant radiochemotherapy. Eighty-one patients with 24 months' follow-up were assessable. Low anterior resection (LAR) was performed in 64 (79%) patients and abdominoperineal resection (APR) in 17 (21%). Twentynine (36%) stage II and 52 (64%) stage III patients entered the study. Within 45-60 days from surgery all patients received 5-Fluorouracil chemotherapy at the dose of 500 mg/m2/iv/d 1-5, every 4 weeks, for six cycles. Chemotherapy cycles 3 and 4 were administered at the same daily dose on radiotherapy days 1-3 and 29-31. Radiotherapy total dose consisted of 45 Gy/1.8 Gy/day administered in 5 weeks with 18 MV photon beam to the pelvis with the four field "box" technique. Perineal scar was encompassed only after APR. A boost dose of 5.4 Gy to the tumor bed was given in 3 fractions of 1.8 Gy. Median follow-up was 37 months (range: 24-74 months).

RESULTS AND DISCUSSION: Overall recurrent disease was reported in 28 of 81 patients (34%): local, systemic and both local and systemic relapses in 9 (11%), 14 (17%) and 5 (6%) cases, respectively. According to local extension, recurrence rates were 10% and 48% in stages II and III, respectively. Five-year overall and disease-free actuarial survivals were 64% and 61%, respectively. Median time to relapse was 15 months (range: 7-43 months). Significant prognostic factors for better tumor control were: stage (II vs III), disease site (proximal vs distal rectum), the surgical procedure (LAR vs APR), the number of involved nodes (< or = 4 vs > 4) and no extracapsular node invasion. The recommended dose of combined radiochemotherapy regimen used in this trial was generally well tolerated. The incidence of any grade > or = 3 acute toxicity (according to WHO grading) was 20% diarrhea, 6% tenesmus and 4% myelosuppression. Five (6%) patients had cronic diarrhea and other 3 (4%) radiotherapy-related severe late toxicity which required surgery.

CONCLUSIONS: This study seems to provide similar survival and recurrence notes to other radio-chemotherapy regimens published in the literature. However, a more aggressive approach is warranted in stage III patients considering the low 5-year survival recorded.