Anal Cancer Treatment

There are several anal cancer treatments depending on the specific type and location of the tumor. The most common type of cancer of the anal region is squamous cell carcinoma which usually arises from the cells lining the anal margin and most of the anal canal. Adenocarcinomas are less common but can arise from the perianal glands in the area. These types of tumors are more common further internal in the rectum, the final part of the large intestine. Less commonly, other pathologies such as Paget's disease, basal cell carcinoma, melanoma and others can affect the anal region.

Factors that affect the anal cancer treatment that is most appropriate include stage of the cancer (how advanced and invasive it is in the body), the type and location of the tumor. In general, three main types of treatments can be involved in the treatment of anal cancer, radiation therapy, chemotherapy and surgery.

Types of Treatments

Chemotherapy: Chemotherapy is treatment of cancer cells by medications that help kill abnormal cells. It is used most commonly in cases where the tumor is invasive and is widespread in the body or as an adjuvant treatment with other treatments. Very advanced, invasive cancers, particularly if they have metastasized, may undergo only chemotherapy and/or radiation. Surgery may only be performed in these cases to alleviate symptoms.

Surgery: Anal cancer treatment by surgical procedures is common. The specific type of surgical procedure varies considerably depending on the location, size and invasiveness of the cancer. For smaller and less invasive cancers diagnosed at early stages, a local resection can sometimes be performed. In this case, just the tumor with a small rim of normal tissue around it is directly removed surgically. This is the best tolerated procedure if it can spare the sphincter muscles of the anus, allowing the patient to continue to control their bowel movements. More advanced tumors that have invaded deeper into the wall of the anus and/or rectum often cannot undergo just a local resection such as this. Local resection is usually offered for Stage 0 tumors (carcinoma in situ) and some Stage I cancers. Radiation and/or chemotherapy treatments may accompany these, particularly for Stage I cancer.

For more invasive tumors, a larger surgical resection may be required. One of the most common types is called an abdominoperineal resection. In this major procedure, the complete anus, rectum and sometimes part of the sigmoid colon are all removed through an abdominal incision. This radical removal, necessary for very invasive and advanced cancers, clearly does not leave the anus intact and therefore the patient requires a colostomy. The colostomy is an area where the surgeon attaches the cut end of the colon to the wall of the abdomen so that feces can be caught by a disposable bag called a colostomy bag. In some tumors that are higher up in the rectum, the anus can be spared and the residual colon can be reattached to the anus either immediately or at a latter date. In these larger abdominal procedures there is usually a removal of many lymph nodes from the abdomen that may contain cancer. Generally, higher stages of cancer will require more aggressive treatments but each patient is different and the decision to perform local versus more aggressive surgical resections depends on the specifics of each case.

Other Treatments: Although the above anal cancer treatments are the most common and standard types of treatment, some other forms of treatment are offered as part of clinical trials, research to evaluate the safety and efficacy of new modes of treatment. For example, radiosensitizer medications may be used along with radiation therapy, new types of radiation delivery and chemotherapy may be evaluated. Patients who have treatment but then recur, the cancer coming back, may require further treatment or may be offered experimental therapies being tested in a clinical trial.