The Connection Between Cervical Cancer and Human Papillomavirus (HPV)

Medical research shows that the strongest link to cervical cancer is infection with the human papillomavirus (HPV). HPV infection is connected to 95 percent of all cervical cancer cases worldwide. But in a recent study in London, England, less than a third of respondents knew what HPV was and only a fraction more knew about the connection between HPV and cervical cancer.

The human papillomavirus family consists of over 100 different "strains," or types, of HPV. These viruses can be as non-threatening as common warts on the hands or feet, or as deadly as the virus that causes cervical cancer. Current studies are examining the connection between HPV and cervical cancer. While most women with cervical cancer have HPV, not all women with HPV will develop cervical cancer.

Some types of HPV can cause genital warts—cauliflower-like growths on the outer skin of the genitals of men or women. These are considered "low-risk" lesions and are not linked with cancer. Other types, however, have been associated with cancer of the cervix. The "oncogenic" (cancer causing) types of HPV are referred to as HPV 16 and 18 and are found in over 90 percent of cases of cervical cancer. Studies of the HPV virus have led to the discovery that the virus produces two proteins that directly affect the growth of the infected host cells.

The human papillomavirus can live in the body for many years without causing any symptoms. This is why having regular Pap smears to detect changes in the cells of the cervix is important. Pre-cancerous cells or early stage cancer can be isolated and destroyed to prevent metastasis to other parts of the body.

Further studies are evaluating the effectiveness of a vaccine to prevent cervical cancer caused by HPV-16, a specific strain of the virus found in about half of all cervical cancer cases. The vaccine boosts the antibodies against HPV-16 and appears to prevent infection by HPV-16.

New research on the HPV-16 vaccine has found that the antibodies produced by the body in response to the vaccine drop during ovulation in women not taking birth control pills. This means that for a short time during each menstrual cycle these women are open to infection. Antibody levels remain at a protective level in women using birth control pills. However, long-term use of birth control pills increases the risk of cervical cancer.

At least twenty other strains of human papillomavirus are linked to cervical cancer, however. Researchers are working on a vaccine that would provide protection against the most common of these strains and protect against non-cancer causing genital warts.

Although these vaccines would not take the place of Pap smear screening they may aid in reducing mortality from cervical cancer.