Chemotherapy and Radiation for Anal Cancer
- Introduction to Anal Cancer
- Risk Factors & Screening
- Staging of Anal Cancer
- Anal Cancer Surgery
- References
Chemotherapy and Radiation
Chemotherapy and radiation is now the gold standard of treatment of anal cancer and results in resolution of the cancer in >80% of cases. Prior to the 1970’s surgery involved removing the distal rectum, anus and sphincter muscles, but the recurrence risk was almost 50%. Dr. Norman Nigro is credited for using chemotherapy (5 Fluorouracil and Mitomycin C) together with radiation to vastly enhance the results of the surgical approach. Eventually he found that such treatment led to complete tumor resolution within the surgical specimens in most cases and discovered that patients that refused surgery were cured and did not recur.[1] Now it is standard to see cure of anal cancer with the Nigro protocol and surgery is reserved for only those cancers which do not resolve post treatment or recurrent tumors after initially seeing complete resolution.
Because of the toxicity of the Mitomycin C which is given as part of the standard protocol, researchers have tried other chemotherapeutic agents, but nothing is superior. Cisplatin has been used in place of Mitomycin and does seem to work as well with less toxicity. It is more commonly used for patients who are deemed too frail to withstand the Mitomycin C.[2]
The treatment of chemotherapy and radiation are given concurrently because they enhance the others effects. The total treatment lasts roughly 6 weeks and is usually managed by a medical oncologist and radiation oncologist. Once complete a colorectal surgeon is typically someone who examines you to ensure complete resolution of the tumor, and periodic exams thereafter to make sure it does not return. Sometimes those exams are done with the patient anesthetized so that biopsies can be obtained. Most importantly, the majority of patients are cured and do not need a colostomy.
References
[1] Nigro ND, Vaitkevicius VK. Combined therapy for cancer of the anal canal: A preliminary report. Dis Colon and Rectum 17:354-56, 1974
[2] Ajani JA, Winter KA, Gunderson LL. Fluorouracil, mitomycin, radiotherapy vs. fluorouracil, cisplatin radiotherapy for carcinoma of the anal prednisone canal. JAMA 299: 1914-21, 2008
