Risk and Prevention  /   Sexual History & Human Papillomavirus (HPV)

You may wonder why your sexual history is discussed as part of your cancer risk. In a nutshell, the reason is the Human Papilloma Virus or HPV. While many women are aware that HPV is the cause of cervical cancer and dysplasia, many are not aware that HPV is a cause of cancers of the vagina, vulva, penis , anus and oral cavity (most often the tongue, tonsils, uvula, or oral cavity). While HPV is referred to as a sexually transmitted disease, you do not need to have intercourse to contract HPV or spread it to your partner. Although experts do not know all the ways HPV is spread, we do know it can be passed on during vaginal or anal penetration, oral sex (with either men or women), genital skin-to-skin sexual contact or genital touching (masturbation). While condom use may decrease areas that are exposed, it cannot prevent exposure completely since HPV can be found on the scrotum, inner thigh and vulva. Additionally, some evidence indicates that HPV may be able to travel through condoms.

Over 130 types of HPV have been identified, some infect the skin or genital area and cause warts, others infect the genital area and can lead to cancer. Those that can cause cancer are called "high risk" strains and infection with these strains typically causes no symptoms. HPV is the most common sexually transmitted disease, with over 75% of men and women infected at some time in their lives. In most cases, the body's immune system will clear the infection on it's own. However, for some, the infection will remain and may lead to cancer in the infected area. Researchers have found that smoking is one factor that makes it harder for the body to clear an HPV infection.

What sexual practices increase risk? Higher numbers of sexual partners and earlier age of first sexual encounter, both of which may increase your exposure to HPV and your chances of being infected. Studies have found that anal sex can increase the risk of anal cancers and oral sex (performed by or on either sex) can increase the risk of oral cancers. However, HPV can be spread to these areas without engaging in these practices. In fact, women with a history of cervical dysplasia should be aware that this increases their risk of anal infection with HPV. So, what can you do to decrease risk? Educate yourself about the virus, understand that all sexual activity can transmit the virus (not just intercourse) and learn more about prevention through vaccines and screening tests.

Learn more about HPV from:

• The Centers for Disease Control
• McGill University
• The American Cancer Society
• The National Cancer Institute

Men who have engaged in anal receptive intercourse can learn more about anal pap testing through the UCSF website.