HPV infection: How does it cause cervical cancer?

How does HPV cause cervical cancer?

- No name given / Virginia

Answer

Human papillomavirus (HPV), a sexually transmitted infection, is the most common cause of cervical cancer. When a woman is exposed to HPV, her immune system usually prevents the virus from doing any harm.

But in a small number of women, the virus survives for years and eventually converts some cells on the surface of the cervix into cancer cells. These changes happen very slowly.

At first, the cells only show signs of a viral infection. Later, the cells become precancerous. Doctors refer to this as cervical intraepithelial neoplasia. In time, it progresses to invasive cervical cancer.

It's not clear why some women are more likely to develop cervical cancer. Some types of HPV are more aggressive than others and that plays a role. Cigarette smoking increases the risk of both precancerous changes and cancer of the cervix. The best way to prevent sexually transmitted infections is to have fewer sexual partners and to always use condoms.

The HPV vaccine (Gardisil), which was approved by the Food and Drug Administration in June 2006, is another way to protect against HPV infection. The vaccine protects against the main types of HPV that cause cervical cancer. Although the vaccine is most effective if given to girls before they become sexually active, the vaccine may also benefit women who are already infected with one or more types HPV by protecting them against the HPV types they don't have.

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