Anal cancer
Definition
Anal cancer is cancer that starts in the anus. The anus is the opening at the end of your rectum. The rectum is the last part of your large intestine where solid waste from food (stool) is stored. Stool leaves your body through the anus when you have a bowel movement.
Anal cancer is fairly rare. It spreads slowly and is easy to treat before it spreads.
Causes
Anal cancer can start anywhere in the anus. Where it starts determines the kind of cancer it is.
The cause of anal cancer is unclear. However, there is a link between anal cancer and the infection. HPV is a sexually transmitted virus that has been linked to other cancers as well.
Other major risk factors include:
Symptoms
Rectal bleeding, often minor, is one of the first signs of anal cancer. Often, a person mistakenly thinks the bleeding is caused by .
Other early signs and symptoms include:
Exams and Tests
Anal cancer is often found by an anorectal examination (DARE) during a routine physical exam.
Your health care provider will ask about your health history, including sexual history, past illnesses, and your health habits. Your answers can help your provider understand your risk factors for anal cancer.
Your provider may ask for other tests. They might include:
If any tests show you have cancer, your provider will likely do more testing to "stage" the cancer. helps show how much cancer is in your body and whether it has spread.
The stage of the cancer will determine how it is treated.
Treatment
Treatment for anal cancer is based on:
In most cases, anal cancer that hasn't spread can be treated with and together. The combination of radiation and chemotherapy achieves better tumor control than the use of radiation alone.
For very small tumors, surgery alone is typically used, instead of radiation and chemotherapy.
If cancer remains after the radiation and chemotherapy, surgery is often required. This may involve removing the anus, the rectum, and part of the colon. The new end of the large intestine will then be attached to an opening (stoma) in the abdomen. This procedure is called a . Stools moving through the intestine drain through the stoma into a bag attached to the abdomen.
Support Groups
Cancer affects how you feel about yourself and your life. You can ease the stress of illness by joining a . Sharing with others who have common experiences and problems can help you feel less alone.
You can ask your provider or the staff at the cancer treatment center to refer you to a cancer support group.
Outlook (Prognosis)
Anal cancer spreads slowly. With early treatment, most people with anal cancer are cancer-free after 5 years.
Possible Complications
You may have side effects from surgery, chemotherapy, or radiation therapy.
When to Contact a Medical Professional
See your provider if you notice any of the possible symptoms of anal cancer, especially if you have any of the risk factors for it.
Prevention
Since the cause of anal cancer is unknown, it's not possible to completely prevent it. But you can take steps to lower your risk.
All adults with HIV should have the following screening test for anal cancer:
Adults with HIV should have other tests along with (HRA), rather than standard anoscopy, if they are:
If HRA is not available, people with HIV should continue to be screened using an assessment of symptoms and DARE. People with any symptoms or signs of anal cancer should have standard anoscopy, without the collection of anal specimens for diagnosis.
References
Hallemeier CL, Haddock MG. Anal carcinoma. In: Tepper JE, Foote RL, Michalski JM, eds. Gunderson & Tepper's Clinical Radiation Oncology. 5th ed. Philadelphia, PA: Elsevier; 2021:chap 59.
Clinicalinfo.hiv.gov website. Guidelines for the Prevention and Treatment of Opportunistic Infections in Adults and Adolescents With HIV. clinicalinfo.hiv.gov/en/guidelines/hiv-clinical-guidelines-adult-and-adolescent-opportunistic-infections/human?view=full. Updated July 9, 2024. Accessed August 2, 2024.
Madoff RD, Melton GB. Diseases of the rectum and anus. In: Goldman L, Cooney K, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 131.
National Cancer Institute website. Anal cancer treatment (PDQ) - health professional version. www.cancer.gov/types/anal/hp/anal-treatment-pdq. Updated January 19, 2024. Accessed August 2, 2024.
Review Date: 8/15/2022
Reviewed By: Todd Gersten, MD, Hematology/Oncology, Florida Cancer Specialists & Research Institute, Wellington, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team. Editorial update 08/15/2024.
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