Human papillomavirus screening and cervical cancer prevention

Infection with one of several types of human papillomavirus (HPV) appears to be a necessary first step in the development of invasive cervical cancer. We cannot currently treat HPV infections; thus, the role of HPV testing is to identify women with precancerous lesions that can be removed and, in so doing, prevent progression to invasive carcinoma. Although HPV testing may help to identify women at risk of cervical cancer who might be missed by other screening tests, it is inherently nonspecific at identifying those who would otherwise develop cervical cancer. In order to avoid overtreatment of women with minor lesions with little potential for progression, HPV testing needs to be repeated or combined with Pap smears. Protocols for HPV screening have yet to be properly evaluated. Here we consider several possible applications of HPV testing in the prevention of cervical cancer. The most immediate role is as a secondary test in women with minor cytological abnormalities. Appropriate use of HPV testing as a primary screening tool depends on the setting. In a developed country without an organized screening program, HPV testing might be used in addition to Pap smears in women age 35 and over to increase sensitivity. Within an organized screening program, HPV testing might be used in combination with Pap testing, but with extended screening intervals so as to obtain the maximum advantage to women without unduly increasing costs. Where resources are strictly limited, an attractive option would be to perform visual inspection of the cervix after application of dilute acetic acid using a low threshold for referral, and to test for HPV only on those with abnormal looking lesions.