Impact of radiation dose on locoregional control and survival on squamous cell carcinoma of anal canal.

Abstract

To perform a systematic analysis of clinical data of presentation, treatment, outcome, toxicity, survival and other associated prognostic factors of the patients of anal canal who received treatment at our hospital. The medical records of 257 patients treated with radiotherapy with or without chemotherapy from the year 1985 to 2005 were studied. Median follow-up was 36months. Complete clinical response after radiotherapy was 74.4% in the whole group. The 5years overall (OAS) and disease-free (DFS) survival for the whole group was 71.5% and 61%, respectively. Patients with T1-2 tumors which received the radiation dose between 55 and 60Gy had superior locoregional control, DFS and OAS. Similarly T3-4 tumors receiving radiation dose more than 60Gy independently improved the locoregional control, DFS and OAS irrespective of the nodal status and addition of chemotherapy. Radiation dose of 56-60Gy for T1 and T2 and 65Gy for T3 and T4 tumors along with concurrent chemotherapy is required to achieve better local control, disease-free survival and overall survival, with acceptable toxicity.