Long-term outcome after combined radiochemotherapy for anal cancer - Retrospective analysis of efficacy, prognostic factors, and toxicity

Background: This retrospective study evaluated the efficacy, prognostic factors, and toxicity of combined radiochemotherapy for anal cancer. Patients and Methods: Data of 90 patients treated with radiochemotherapy between 1990 and 2006 were analyzed. Mean follow-up was 30 months (range: 2-129 months). Endpoints were disease-specific survival, local control, freedom from metastasis, and colostomy-free survival. Tumor stage, nodal status, age, sex, tumor site, tumor resection, and radiation dose were analyzed for prognostic value. Acute toxicity was scored according to the RTOG/EORTC scale, late toxicity according to the LENT/SOMA scale. Results: Disease-specific survival was 86%, local control 79%, freedom from metastasis 92%, and colostomy-free survival 83%. Higher T category was associated with inferior prognosis for colostomy-free survival (p = 0.000), male sex for local control (p = 0.004) and disease-specific survival (p, = 0.002), and tumor site at the anal margin for local control (p = 0.03). 4 of 7 patients with recurrent anal margin tumors had human papillomavirus (HPV)-related disease. 49% of patients suffered from >= grade 3 acute toxicity. 3 patients had late toxicity of grade 3 concerning sphincter control. Conclusion: Combined radiochemotherapy for anal cancer is a highly effective therapy with pronounced acute and minor late toxicity. In the case of higher T stage, male sex, and cancer at the anal margin, treatment intensification should be considered.