Randomized Clinical Trials in Localized Anal Cancer

Management of anal carcinoma began as abdominoperineal resection and has evolved to combined chemotherapy and radiation. Early randomized trials demonstrated superior clinical outcomes of combined modality therapy over radiotherapy alone. Subsequent trials investigated alterations in the standard backbone of radiotherapy concurrent with 5-fluorouracil and mitomycin C with intent to maintain clinical outcomes while reducing treatment-related morbidity. The addition of intensity-modulated radiotherapy to radiation planning and delivery has subsequently reduced acute toxicity and detrimental treatment breaks. Ongoing and future trials are aimed at reducing therapy in favorable patient populations to decrease morbidity while intensifying treatment in patients with negative prognostic factors.