Carcinoma of the anal canal

From 1975 to 1990 65 patients with carcinoma of the anal canal received radiation therapy alone or in conjunction with other modalities. Follow-up ranged from 12 to 171 months (mean: 59 months; median: 44 months). Actuarial disease-free survival (including salvage surgery) for T1-3 N0 lesions was 88% +/- 7% at 10 years. This was independent of T stage (91% for T1, 88% for T2, and 100% for T3). Disease-free survival was significantly worse for T1-3 N+ lesions (52% +/- 23% disease-free at 10 years, P = .025) and T4 lesions (0/8 disease free by 21 months, P < .001). Of the 57 patients with T1-3 lesions, 46 received low to moderate doses of radiation (< or = 5,000 cGy) in conjunction with infusional 5FU based chemotherapy. These were reviewed for treatment related factors. Among patients treated with low to moderate dose chemoradiotherapy the local control (including salvage surgery) was excellent: 100% for T1 lesions and 88% +/- 6% for T2, 3 lesions. There was a suggestion that increasing the dose of radiation to the tumor may reduce the need for surgery for T2, 3 lesions. For T2, 3 lesions the local control excluding surgery was 63% +/- 12% with 3,000 cGy plus chemotherapy, as opposed to 77% +/- 11% with 4,000-5,000 Gy (mean 4,600 cGy) plus chemotherapy. The most important factor for posttreatment toxicity was the addition of pelvic surgery to chemotherapy and radiotherapy. Eighteen patients who received chemoradiotherapy either had a history of prior pelvic surgery (five cases) or underwent APR following chemotherapy (13 cases). There were a total of nine grade 3 or 4 complications (including all five cases of small bowel obstruction) in this group. There was a significantly lower (P = .04) incidence of complications in the remaining patients: 2/47 (4%). It should be noted that no patient required a colostomy for management of treatment sequelae, the interventions taken were all successful in managing complications, and no complication was fatal. Nonetheless these results suggest that, for some T3 and T2 lesions, measures which reduce the need for salvage surgery might improve overall quality of life by reducing complications, although it may prove difficult to demonstrate an improvement in the excellent disease-free survival. In addition, measures should be taken to reduce the volume of irradiated bowel if a patient has a history of prior pelvic surgery.