High risk of colostomy with primary radiotherapy for anal cancer.

Background: Radiotherapy (RT) has become the primary treatment of choice for anal cancer in an effort to avoid colostomy. The current role of surgery appears generally to be underestimated, since diverting colostomy or abdominoperineal resection still often seems to be necessary for complications and local treatment failure after RT.

Methods: The data of 83 patients primarily treated by RT with curative intent throughout a 20-year period in our institute were analyzed regarding the need for colostomy.

Results: Totally, 28 patients (34%) required creation of a colostomy after primary RT for local failure or treatment-related complications during a mean follow-up period of 39 months. The 3-year actuarial colostomy-free rate was 59% (mean 85 +/- 9 months). Early stage disease, low T-score and absence of infiltration in adjacent organs were associated with a reduced need for colostomy in univariate analysis. In multivariate analysis only T-score was an independent variable in predicting prolonged colostomy-free interval. In this study, no statistically significant differences were noted for gender, age, nodal status, total radiation dose, radiation boost and concurrent chemotherapy.

Conclusions: In approximately one-third of the patients treated by anal sphincter saving management with curative aimed primary RT, the creation of a colostomy appeared to be necessary for RT complications and local treatment failure. Therefore, patients should be well informed regarding the considerable risk of need for colostomy after RT for anal cancer.