How is anal cancer treated?

Chemo + tradiation. Usually with a surgical biopsy followed by chemotherapy and radiation therapy. In general, the prognosis is pretty good and surgery is used only for treatment failures.
Combination. Anal cancer should be treated with a combination of radiation, chemotherapy and, if needed, surgery. See the site below for more info about anal cancer. http://www.mayoclinic.org/anal-cancer/.