Which of the following is the treatment of choice in the management of carcinoma of the anal canal?

A combination of chemotherapy and radiotherapy, so-called chemo radiation (Nigro) is the preferred initial therapy for all anal canal tumours. In such patients a combination of 5 flourouracil and mitomycin is given for approximately 1 week and chemotherapy is followed by radiotherapy, given over 3-7 weeks. Ref: Bailey and Love's Sho Practice of Surgery, 24th Edition, Pages 1269-71.