Anal Cancer

Signs and Symptoms

Anal cancer is an uncommon cancer that develops in the last part of the rectum near the skin.

Common signs and symptoms of anal cancer include:

• A change in bowel habits
• Diarrhea, constipation or feeling that the bowel does not empty completely
• Blood, either bright red or very dark in the stool
• Stools that are narrower than usual
• General abdominal discomfort, such as frequent gas pains, bloating, fullness or cramps
• Weight loss with no known reason
• Constant tiredness

Diagnosis

To help find the cause of symptoms, your doctor will evaluate your medical history. Your doctor will perform a physical exam and may recommend one or more of the following diagnostic tests:

• Sigmoidoscopy to see inside the rectum and the lower colon and remove polyps or other abnormal tissue for examination under a microscope
• Colonoscopy to see inside the rectum and the entire colon and remove polyps or other abnormal tissue for examination under a microscope
• Polypectomy to remove a polyp during a sigmoidoscopy or colonoscopy
• Biopsy to remove tissue sample for examination by a pathologist to make a diagnosis

If the diagnosis is cancer, your doctor needs to learn the stage or extent of disease. Staging is a careful attempt to find out whether the cancer has spread and if so, to what parts of the body. More tests may be performed to help determine the stage. Knowing the stage of the disease helps your doctor plan treatment. Listed below are descriptions of the various stages of colorectal cancer:

• Stage 0: The cancer is very early. It is found only in the innermost lining of the rectum.
• Stage I: The cancer involves more of the inner wall of the rectum.
• Stage II: The cancer has spread outside the rectum to nearby tissue, but not to the lymph nodes. (Lymph nodes are small, bean-shaped structures that are part of the body's immune system.)
• Stage III: The cancer has spread to nearby lymph nodes, but not to other parts of the body.
• Stage IV: The cancer has spread to other parts of the body. Anal cancer tends to spread to the liver, lungs or abdominal cavity.
• Recurrent: Recurrent cancer means the cancer has come back after treatment. The disease may recur in the pelvis or in another part of the body.

Treatment

Surgery
The optimal management of anal cancer may not require surgery after the biopsy is performed. While a surgeon may be able to take out the cancer from the anus using a variety of methods, the preferred treatment may be chemotherapy and radiation.

Radiation therapy
Radiation therapy uses X-rays or other high-energy rays to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body, or external radiation therapy, or from putting materials that produce radiation, or radioisotopes, through thin plastic tubes in the area where the cancer cells are found, called internal radiation therapy. Radiation can be used alone or in addition to other treatments.

Chemotherapy
Chemotherapy uses drugs to kill cancer cells. Chemotherapy may be taken by pill, or it may be put into the body by a needle in a vein or muscle. Chemotherapy is called a systemic treatment because the drugs enter the bloodstream, travel through the body, and can kill cancer cells throughout the body. Some chemotherapy drugs can also make cancer cells more sensitive to radiation therapy. Radiation therapy and chemotherapy can be used together to shrink tumors and make surgery unnecessary. When only limited or no surgery is required, the sphincter muscle can often be saved.