Anal Cancer Risk Factors

Risk Factors and Prevention

A risk factor is anything that increases a person’s chance of developing cancer. Some risk factors can be controlled, such as smoking, and some cannot be controlled, such as age and family history. Although risk factors can influence the development of cancer, most do not directly cause cancer. Some people with several risk factors never develop cancer, while others with no known risk factors do. However, knowing your risk factors and communicating them to your doctor may help you make more informed lifestyle and health-care choices.

The following factors may raise a person’s risk of developing anal cancer:

Human papillomavirus (HPV) infection. Research indicates that infection with this virus is a risk factor for anal cancer. HPV is most commonly passed from person to person during sexual activity. There are different types, or strains, of HPV, and some strains are more strongly associated with certain types of cancer. Learn more about HPV and cancer.

Age. Most people diagnosed with anal cancer are between age 50 and 80. Frequent anal irritation. Frequent anal redness, swelling, and soreness may increase the risk of developing anal cancer.

Anal fistula. An anal fistula is an abnormal tunnel between the anal canal and the outer skin of the anus that often drains pus or liquid, which can soil or stain clothing. An anal fistula may irritate the outer tissues or cause discomfort. An anal fistula may increase the risk of developing anal cancer.

Cigarette smoking. Cigarettes can cause harm throughout the body, because chemicals from cigarettes can enter the bloodstream and affect nearly every organ and tissue in the body. Smokers are about eight times more likely to develop anal cancer than nonsmokers.

Lowered immunity. People with diseases or conditions affecting the immune system, such as HIV or organ transplantation, and people who take immunosuppressive drugs that make the immune system less able to fight disease, are more likely to develop anal cancer.

Prevention

Even though some people who have no risk factors develop anal cancer, there are ways to prevent or reduce your risk of developing anal cancer.

• Avoid anal sexual intercourse, which carries an increased risk of HPV and HIV infection.
• Limit the number of sex partners, because having many partners increases the risk of HPV and HIV infection.
• Use a condom. However, even though condoms can protect against HIV, they cannot fully protect against HPV.
• Stop smoking.

Anal cancer screening. Anal cytology is a test being developed that doctors can use for people who don’t have symptoms of anal cancer but do have a high risk of contracting a sexually transmitted disease (STD) such as HPV and HIV. The test is similar to a Pap test, which looks for cervical cancer, except this test looks for anal cancer.

The doctor can swab the anal lining and look at the cells on the swab under a microscope to find early cellular changes that might lead to cancer or may diagnose cancer from this swab. Some doctors are advocating the routine use of this test for men who have HIV and who have sex with men and for other people who are at high risk for developing anal cancer.