Treatment of anal cancer
Up until 20 years ago, treatment for anal cancer was resection by radical surgery which led to a permanent colostomy. However, anal cancer is a cancer type that is sensitive to radiation. With radiation therapy, the sphincter muscle can be preserved, and colostomy can be avoided in up to 80 % of patients. Radiation therapy with or without chemotherapy has given better survival results, and therefore replaced surgery as primary treatment in the 1980s.
Radiation therapy combined with chemotherapy (5-fluorouracil and mitomycin C) is the primary choice of treatment providing better response, better local control and better colostomy-free survival than radiation therapy alone. However, hematologic toxicity can be significant. The treatment is also given for palliative purposes to patients with advanced disease to reduce local side effects in the pelvis.
Surgery as primary treatment is performed today for limited indications such as resection of small (< 1 cm) perianal, high and moderately differentiated tumors that can be removed without involvement of the sphincter muscle. For a marginal resection (< 5 mm), a reexcision should be performed. More extensive surgery is indicated if, after chemoradiation as primary treatment, there is still remaining tumor, or remaining tumor does not disappear after 2-3 months observation time. A rectum amputation is then often necessary and may cure the disease. Rectal amputation is reserved for persistent disease after chemoradiation or for local recurrence.
Metastases are treated with chemotherapy, possibly followed by surgery.
The treatment of giant condyloma is primarily surgery in contrast to perianal cancer as chemoradiation does not appear to have any substantial effect. Radiochemotherapy is given in some advanced cases. Experience is based on reported case statistics. Local podophyllin treatment may be effective treatment for condyloma acuminatum, but has no effect on giant cell condyloma.