Radiation treatment of epidermoid cancer of the anus

The purpose of this study was to evaluate our treatment results of anal cancer.

During the years 1985-1990, 82 patients with invasive epidermoid and cancer were referred to the Department of Oncology at Södersjukhuset. In 76 cases irradiation was used in the primary therapy, and in 43 cases bleomycin was administered concurrently. Fifteen of these tumors were situated in the perianus and 61 in the anal canal. Probability of survival, recurrence, and preservation of anal sphincter was analyzed according to Kaplan-Meier. Cox multivariate analysis was used in studying potential determinants of risk for treatment failure.

Tumor-specific survival at 5 years was 71% for both anal canal and perianal cancer. Analyses with regard to cancer of the anal canal indicated that T4 tumors had significantly worse prognosis than those in stages T1-3. Overall survival was 73% and 79% at 5 years for T1 and T2 tumors and 73% and 18% at 4 years for T3 and T4 tumors. Corresponding figures for tumor specific survival were 79%, 79%, 82%, and 31%. Eighty-five percent of patients with T1 tumors, had a preserved anal sphincter after 4 years. For T2 and T3 tumors the corresponding figures were 62% and 60%. Also the multivariate analyses showed stage T4 to be a strong negative prognostic determinant. There was no firm evidence of a positive effect of bleomycin on the treatment results, but it increased the acute radiation toxicity.

Primary radiotherapy of anal cancer yielded a high probability of survival, but in many cases sphincter amputation have been necessary. The role of bleomycin appears questionable.