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Anal Cancer Screening, Prevention and Treatment

How is anal cancer treated?

Treatment for most cases of invasive anal cancer is very effective. There are 3 basic types of treatment used for anal cancer:

  • Surgery – an operation to remove the cancer
  • Radiation Therapy – high-dose x-rays to kill cancer cells, and
  • Chemotherapy – giving drugs to kill cancer cells.

Combination therapy including radiation therapy and chemotherapy is now considered the standard treatment for most anal cancers.

What is anal cancer?

Anal cancer arises from the cells around the anal opening or within the anal canal. Although several other types of cancer may occur in this area, squamous cell cancers are the most common. Cells that are becoming malignant but have not invaded below the epithelial surface are “pre-cancerous” and are called “carcinoma-in-situ”.

What are possible risk factors?

  • Anal warts – Infection with the human papilloma virus (HPV) which causes condyloma (warts) increases the chance of developing anal cancer.
  • Anal sex – Persons who participate in anal sex are at an increased risk.
  • Smoking – Harmful chemicals from smoking increase the risk of most cancers including anal cancer.
  • Immunosuppression – People with weakened immune systems, such as transplant patients who must take drugs to suppress their immune systems and patients with HIV (human immunodeficiency virus) infection, are at higher risk.
  • Chronic local inflammation – People with long-standing anal fistulas or open wounds are at a slightly higher risk.
  • Pelvic radiation – People who have had pelvic radiation therapy for rectal, prostate, bladder or cervical cancer are at an increased risk.

How can I reduce my risk to get anal cancer?

Reduce your risk by getting regular checkups, anal pap smears and High Resolution Anoscopy (HRA)

What is High resolution Anoscopy?

High resolution Anoscopy or HRA is a procedure that allows for examination and evaluation of the anal canal.

Using a small thin round tube called an anoscope, the anal canal is examined with a high resolution magnifying instrument called a colposcope. Application of a mild acidic liquid onto the anal canal facilitates evaluation of abnormal tissue such as anal dysplasia. If indicated, a biopsy can be obtained. A digital rectal examination is also done at the time of the procedure.

Pre-cancerous lesions (high grade intraepithelial neoplasia, AIN 2 or AIN 3) or carcinoma-in-situ can be treated with Infrared Photocoagulation in the office so that they do not become invasive cancer, which is more involved to treat. The procedure is performed in the office and generally lasts about 15 minutes. It is usually very well tolerated with mild if any discomfort. Significant risks such as bleeding or infection are extremely rare.

Note should be taken that high resolution anoscopy is very different from colonoscopy or flexible sigmoidoscopy, neither of which can adequately exam the anal canal for the problems being detected by HRA. No bowel prep is needed for this examination.

This service is available at RCRS.

What are the symptoms of anal cancer?

  • Bleeding from the rectum or anus
  • Pain or the feeling of a lump or mass at the anal opening
  • Persistent or recurrent itching
  • Change in bowel habits (having more or fewer bowel movements) or increased straining during a bowel movement
  • Narrowing of the stools
  • Discharge (mucous or pus) from the anus
  • Swollen lymph nodes (glands) in the anal or groin areas

If you have any of these symptoms, see your doctor or a colorectal surgeon.

How is anal cancer diagnosed?

Anal cancer is diagnosed with a digital (finger) exam of the rectum and anus, performance of an anoscopy or as needed with the aid of an endoscopic exam (e.g. flexible sigmoidoscopy). If anal cancer is suspected based on your doctor’s exam, a biopsy will be performed to confirm the diagnosis. If the diagnosis of cancer is confirmed, additional tests to determine the extent of the cancer may be recommended.

Conclusion

Anal cancers are tumors arising from the skin or mucosa of the anal canal. As with most cancers, early detection is associated with excellent survival. Screening, including HRA, can help to prevent anal cancers. Most anal cancers are well treated with combination chemotherapy and radiation alone. Surgery is often reserved for advanced cancers or anal cancers that have not responded to chemo- and radiation therapy.