CARCINOMA OF THE ANAL-CANAL

From 1975 to 1990 65 patients with carcinoma of the anal canal receive d radiation therapy alone or in conjunction with other modalities. Fol low-up ranged from 12 to 171 months (mean: 59 months; median: 44 month s). Actuarial disease-free survival (including salvage surgery) for T1 -3 N0 lesions was 88% +/- 7% at 10 years. This was independent of T st age (91% for T1, 88% for T2, and 100% for T3). Disease-free survival w as significantly worse for T1-3 N+ lesions (52% +/- 23% disease-free a t 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 mod erate doses of radiation (less-than-or-equal-to 5,000 cGy) in conjunct ion with infusional 5FU based chemotherapy. These were reviewed for tr eatment related factors. Among patients treated with low to moderate d ose chemoradiotherapy the local control (including salvage surgery) wa s excellent: 100% for T1 lesions and 88% +/- 6% for T2,3 lesions. Ther e 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 c hemotherapy, as opposed to 77% +/- 11% with 4,000-5,000 Gy (mean 4,600 cGy) plus chemotherapy. The most important factor for posttreatment t oxicity was the addition of pelvic surgery to chemotherapy and radioth erapy. Eighteen patients who received chemoradiotherapy either had a h istory of prior pelvic surgery (five cases) or underwent APR following chemoradiotherapy (13 cases). There were a total of nine grade 3 or 4 complications (including all five cases of small bowel obstruction) i n this group. There was a significantly lower (P = .04) incidence of c omplications in the remaining patients: 2/47 (4%). It should be noted that no patient required a colostomy for management of treatment seque lae, the interventions taken were all successful in managing complicat ions, 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 comp lications, although it may prove difficult to demonstrate an improveme nt in the excellent disease-free survival. In addition, measures shoul d be taken to reduce the volume of irradiated bowel if a patient has a history of prior pelvic surgery.