Can anal cancer be caused by HPV spread through sex?

Answer Section

Human papillomavirus (HPV) can cause anal and rectal cancers. Although most people with HPV infections do not get cancer, HPV is the cause of most anal cancers. HPV also can cause cancer of the genitals, mouth and upper respiratory tract. It may be linked to some colon and rectal cancers, but more research is needed. HPV is a common virus that spreads through skin-to-skin sexual contact, including vaginal, oral and anal sex.

There are more than 100 types of HPV. Anal cancers usually form after long-term infection with a high-risk type of HPV, especially types 16 and 18. Receptive anal sex increases the risk of anal cancer because it may be linked to a higher chance of getting high-risk HPV. But HPV can spread to the anal area through other sexual contact, even without anal sex.

In most people, HPV causes no issues and goes away on its own. In others, the virus stays in the body and causes cell changes in the anal area that lead to cancer over time. Anal cancer caused by HPV is usually anal squamous cell carcinoma. It starts in the flat squamous cells that line the anal canal and the skin just outside the anus.

Anal cancer from HPV often grows slowly. It may not cause symptoms at first. When symptoms appear, they can include bleeding from the anus or rectum, anal pain, itching, a lump or growth, or changes in bowel habits. Because these symptoms are common in other conditions, a healthcare professional should check any symptoms that are ongoing.

Practicing safer sex can reduce the risk of HPV infection. This includes using condoms and limiting the number of sexual partners. Condoms reduce risk but do not fully prevent HPV because the virus can infect areas not covered by a condom. Fingers and sex toys also can spread HPV. So clean sex toys between uses or cover them with a new condom. Consider wearing a latex glove during vaginal or anal sex involving the fingers.

The HPV vaccine lowers the risk of HPV infection and related cancers, such as anal cancer. It works best before first sexual contact. But even if you're already sexually active or have one HPV type, the vaccine can protect against other types you do not have. Talk with your healthcare professional about the vaccine and other ways to reduce your risk.