[The anal canal: 2 cycles of radiochemotherapy and boost brachytherapy]

From 1988 to 1996, twenty-six patients with epidermoid anal cancer were examined at the Radiotherapy Department of Università Cattolica del S. Cuore, Rome. At diagnosis, 13 patients were stage II, 11 patients were stage III, 2 patients had a small recurrence after local excision. All the patients were treated with concomitant radiochemotherapy followed by a brachytherapy boost. Treatment was carried out in two cycles 4-5 weeks apart. Chemotherapy consisted of 5FU (1,000 mg/sqm, continuous infusion over the first 4 days) and Mitomycin C (10 mg/sqm on day 1, bolus administration). Radiotherapy was administered with two AP opposed coaxial beams of the same size. The target was T and inguinal, external, internal and common iliac lymph nodes. The total dose for each cycle was 23.4 Gy, administered with conventional fractionation and a daily dose of 180 cGy. Four-six weeks after the end of cycle 2, the patients received a boost of interstitial brachytherapy. During concomitant radiochemotherapy, grade 3-4 (RTOG-EORTC scale) acute hematologic and cutaneous toxicities were observed in 15% and 4% of patients, respectively; treatment was discontinued in 4 patients. Complete response was observed in 21 patients (81%) and partial response in 5 (19%). The later underwent surgery, namely local excision in 1 patient and abdominoperineal resection in 4 patients. The median observation period of our study population was 45 months. Five-year actuarial local control of the 26 patients was 88%. Five year actuarial survival was 75% and sphincter conservation 77%. Our results confirm the data reported by Cummings of Princess Margaret Hospital, who observed low toxicity when the two cycles of concomitant radiochemotherapy are split. Randomized phase-III studies should clarify the potential role of the new radiochemotherapy combinations which should be compared with reference treatments providing repeatable results and low toxicity. Our treatment may make a reference for more innovative combinations of radiochemotherapy.