Neoplastic changes of the cervical epithelium – Genesis of cervical cancer – Role of HPV
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Nearly 95% of cervical cancers are associated with persistent cervical infection with HPV. The natural history of cervical cancer spans a period of years (ranging from 5 to 20 years), starting with HPV infection leading to the development of a precancerous lesion and finally progressing to invasive cancer. HPV is a very common sexually transmitted virus that infects the lower genital tracts of both women and men. It can infect other mucosal surfaces (e.g. that of the anal canal) and the skin (the skin over the vulva, scrotum, penis, and perineum). Most men and women are infected with HPV shortly after they become sexually active. HPV may be transmitted by hand-to-genital contact, and penetrative sexual intercourse is not necessary for its propagation.
In most women (and men), HPV infection is transient and is cleared by the body’s immune response. In a small proportion of women, the body will not be able to clear the HPV infection and the woman will have a persistent infection. Persistent HPV infection is associated with cervical cancer as well as other cancer types, such as vulvar and vaginal cancers in women, penile cancer in men, and anal and oropharyngeal (throat) cancers in both sexes. More details about HPV are available on the next page.