Anal Cancer Prevention and Risk Factors

Understanding what causes anal cancer—and knowing your own risk factors—is an important step toward finding cancer earlier or preventing it altogether. Some risk factors, like age, can’t be changed. But others can. Healthy habits, vaccination, and regular checkups can all help lower your risk.

What are the risk factors for anal cancer?

Experts don’t know exactly what causes anal cancer in every person, but most cases are linked to certain types of human papillomavirus (HPV). Other factors—like other infections, health conditions, and lifestyle habits—can also raise your risk.

HPV (Human Papillomavirus) 

Most anal cancers are thought to be caused by human papillomavirus (HPV), a common sexually transmitted infection.  HPV usually causes no symptoms, and, in most people, goes away on its own. While HPV infection is strongly linked to anal cancer, most people with HPV will never develop cancer. 

There are more than 150 types of HPV, but HPV-16 is the one most often linked to anal cancer. That’s why the HPV vaccine is such an important tool for prevention. 

HIV (Human Immunodeficiency Virus) 

People with HIV, the virus that causes AIDS, have a higher risk of developing anal cancer. HIV weakens the body’s immune system, making it harder to clear HPV infections and fight off abnormal cell growth. People living with HIV may also benefit from regular screening for precancerous anal lesions (HSIL), which can be treated before they develop into cancer.  

Certain types of sexual activity 

Having multiple sexual partners increases your likelihood of being exposed to both HPV and HIV, which increases your risk of anal cancer. Anal intercourse is a known risk factor for both men and women, since it increases the chance of getting infected by HPV. 

Smoking 

Smoking can increase your risk for many cancers, including anal cancer. Tobacco can damage DNA and weaken the immune system’s ability to clear HPV infections. Quitting smoking can significantly lower your risk. 

Lower immunity 

People with weakened immune systems – such as those with AIDS or people taking immunosuppressive medications after organ transplantation – are at a higher risk for anal cancer. A weakened immune system may make it more difficult to fight HPV infection and prevent the growth of abnormal cells.  

Sex and age

Anal cancer is more common in women than in men overall, and the risk increases with age. Most cases are diagnosed in people over 50.  Even though anal cancer is still rare, knowing these patterns can help you stay aware and take steps for prevention.

How to protect yourself from anal cancer

Most people don’t need routine screening for anal cancer, but there are things you can do to lower your risk and take care of your health. 

• Get the HPV vaccine. HPV is the leading cause of anal cancer. The HPV vaccine is the most important way to protect yourself against anal cancer and other cancers. Vaccination is recommended for children and adults between the ages of 9 and 26, and in some cases, up to age 45. 
• Practice safe sex. Use condoms to help reduce the risk of HPV and other sexually transmitted infections. While condoms don’t offer full protection, they can significantly lower the chance of infection. 
• Quit smoking. Smoking increases the risk of anal and other cancers. Stopping smoking can greatly improve your overall health and lower your cancer risk. Learn more about Tobacco Cessation Services 

While routine screening is not recommended for most people, if you are at a higher risk – such as living with HIV, having a history of HPV-related cancers, or taking immunosuppressive medications – talk to your healthcare provider about whether you should be monitored more closely or undergo screening. Screening can detect precancerous anal lesions, called high-grade squamous intraepithelial lesions (HSIL), before they become cancer. Research has shown that treating these lesions significantly reduces the risk of developing anal cancer in people living with HIV.