The principal objectives of treatment are cure and the preservation of function of the anus and rectum. Surgery, radiotherapy and chemotherapy are all used to treat anal cancer.
The prognosis depends on the size and location of the tumor . The outlook is more favorable if the tumor is small (less than 5 cm/2 in.), if there is no lymph node involvement or extension to local organs and if the primary tumor arises in the anal margin rather than the anal canal.
Options by Size of Tumor The choice of conservative surgery or radiotherapy (with or without chemotherapy) for anal or perianal cancer depends on the size of the tumor, local invasion and/or lymph node involvement. Radical surgery (an abdominal-perineal resection) may be required for larger or more extensive cancers, and will result in a loss of anal function, a colostomy , and urinary and sexual malfunction. It is reserved for larger or residual cancers.
• Small tumors—those that are less than 2 cm (1 in.)—can be treated with local excision or radiotherapy alone.
• Tumors 2 to 5 cm (1 to 2 in.) are best treated by chemotherapy plus radiotherapy, leaving surgery for "salvage"
therapy. Some physicians prefer just radiotherapy for small tumors (up to about 3 cm/1 1/4 in.), but most
oncologists today use combined chemotherapy and radiotherapy.
• Tumors larger than 5 cm (2 in.) are treated by chemotherapy and radiotherapy. Surgery is used for residual
