Cervical cancer is caused by persistent infection with high-risk human papillomavirus (hrHPV). In 2008, Harald zur Hausen, a German virologist, won the Nobel Prize in Physiology and Medicine for establishing the link between high-risk genital HPV infection and cervical cancer. Among the fifteen identified high-risk HPV types, HPV16 and HPV18, are associated with about 70% of cervical cancers . The remaining 30% are caused by other high-risk HPV types. HPV transmission is mainly by sexual contact and hence many women become infected within a few years after sexual debut. Accordingly, the main risk factors for HPV infection are defined by sexual (risk) behavior, including life time number of sexual partners and the acquisition of new male partners. HPV prevalence is also high among persons with an immune disorder, such as HIV. Up to 80% of women will at some point in their life have an HPV infection. The majority of infections clears spontaneously and only 5 to 10 percent becomes persistent. These persistent infections may progress to cancer which takes at least 12 years.
Figure: Natural history of cervical cancer
