[Use of molecular tests of human papilloma virus (HPV) as screening test for cervix cancer: a review]

Abstract

Infection from some types of human papillomavirus has been recognised as carcinogenic for the uterine cervix. With reliable techniques (PCR and Hybrid Capture II) "high risk" HPV types are found in a very high proportion of women with invasive cancer and high-grade pre-invasive lesions. On the other hand prevalence is low in cytologically normal women, except in young women, who seem to have a high frequency of transient infections in the years following the beginning of sexual activity. Some studies found a role of the presence and persistence of "high-risk" HPV types in the progression of low-grade pre-invasive lesions vs. high-grade rather then vs. spontaneous regression. For these reasons HPV testing has been suggested as a possible tool for primary screening. A few studies suggest that it could allow increasing sensitivity, although problems of extrapolability of results exist. It must, however, be considered that traditional cytological screening is already very protective and that simply adding a further test would lead to an unfavourable cost-benefit ratio. An appealing possibility is applying HPV testing with long intervals between screening rounds. This would reduce the burden for women and plausibly allow reaching higher coverage at each round. A key element is the duration of infection before progression to pre-invasive lesion. A long duration would allow selecting women at low risk of developing a lesion for years (those HPV-negative), who could have long-interval test, and others (those HPV-positive) at high risk, to be followed more strictly. Published data from longitudinal studies are limited and don't allow an adequately precise estimate. Therefore the use of HPV testing for primary screening is very promising but to the moment must be considered as a research object.