Results of the treatment of squamous carcinoma of the anal canal

From February 1962 to April 1995, eighty-one patients with epidermoid carcinoma of the anal canal were treated at Taipei Veterans General Hospital (Taipei VGH). Forty-nine of these patients were treated by abdominoperineal resection (APR), 22 patients by combined chemoradiation therapy (CRT), while 10 patients received radiation therapy only (RT). The crude four-year survival rate for the different treatment groups was: APR, 59%; CRT, 59%; RT 15% (p=0.029). Cause-specific survival rate at three and five years were: 69%, 60% in APR; 65%, 53% in CRT; 57% (3yr) in RT group (p=0.54). In stage IIIb patients, the five-year cause-specific survival was 27% in APR and 37% in CRT. The study revealed that the survival rate is significantly influenced by local tumor (T) status and the degree of tumor cell differentiation (p=0.05). The local recurrence rate and extrapelvic recurrence rate were 20%, 20% in APR; 31.6%, 26.3% in CRT. It seemed that the higher recurrent rate in CRT was because those were more advanced cases. In CRT group, the complete remission rate at the end of treatment was 86.3 (19/22). The eventual colostomy rate was 32% (7/22); the major factor causing colostomy is local tumor control. These results suggest that CRT is at least as effective as APR and can also avoid the necessity of colostomy for most patients.