According to an article published in Cancer Epidemiology, Biomarkers and Prevention, women infected with multiple types of the human papillomavirus (HPV) have a significantly greater risk of developing cervical cancer than those infected with just one type of HPV.
The cervix is the bottom part of the uterus, or womb, and extends to the top of the vagina. Cervical cancer is the second most common type of cancer diagnosed among women around the world; however, because first-world countries have established highly effective screening programs, cervical cancer is most common in second third-world countries where routine screening is scarce or does not exist.
Human papillomaviruses consist of more than 100 different viruses. Some types of HPV cause warts on the hands or feet; others cause genital warts; and some have been linked with cancer, most notably cervical cancer. The types of HPV most commonly linked with cervical cancer are HPV 16 and HPV 18, but several other high-risk types contribute to cancer as well.
The types of HPV that cause cervical cancer or genital warts are transmitted sexually. HPV infection is extremely common and generally occurs soon after an individual becomes sexually active. Although most infections resolve on their own, some persist and can lead to precancerous or cancerous changes to the cervix, vulva, vagina, penis, and anus.
Researchers from Canada recently conducted a study to evaluate the association between infection with multiple types of HPV and cervical cancer risk among 2,462 Brazilian women. Women underwent pap smears and HPV testing.
- During four years of visits, 22% of women became infected with multiple HPV types.
- Women with multiple HPV infections were at a clearly higher risk of developing cervical cancer than those with just one type of HPV infection.
- The more types of HPV a woman was infected with, the higher the risk of cervical cancer became.
- Among women infected with multiple types of HPV, those infected with HPV-16 and HPV-58 had a particularly increased risk of developing cervical cancer.
The researchers concluded that infection with multiple types of HPV significantly increases a woman’s risk of developing cervical cancer compared to infection with just one type of HPV. Women with multiple HPV infections may benefit from closer follow-up than those who are not infected with HPV or those infected with just one type of HPV.
Reference: Trottier H, Mahmud S, Costa M, et al. Human Papillomavirus Infections with Multiple Types and Risk of Cervical Neoplasia. Journal of Epidemiology, Biomarkers and Prevention. 2006:15; 1274-1280.