Human papillomavirus in cervical screening and vaccination.

Recent decades have witnessed a reduction in the incidence of cervical cancer in countries where screening programmes have achieved broad coverage. The recognized importance of high-risk HPV (human papillomavirus) infection in the aetiology of cervical cancer may introduce a role for HPV DNA testing in cervical screening programmes. Positive HPV DNA tests indicate women at risk of cervical cancer with greater sensitivity, but reduced specificity, compared with exfoliative cytology. Combining HPV testing with cytology may be useful in the triage of minor cytological abnormalities into those requiring referral to colposcopy (HPV positive) compared with those who can be safely managed by cytological surveillance (HPV negative). With its high sensitivity and high-negative-predictive value, HPV testing may also be useful for predicting treatment failure, since residual disease is very unlikely in the event of a negative HPV test. Ultimately, prevention is better than cure, and the advent of HPV prophylactic vaccines may obviate the need for population-based cervical screening programmes in the future. A multivalent vaccine administered to adolescents prior to the onset of sexual activity and boosted at regular intervals throughout their sexually active life may provide protection against type-specific HPV infection, malignant precursors and invasive cervical disease. Several large randomized placebo-controlled trials have been conducted with promising results. For those generations of women already exposed to high-risk HPV infection, therapeutic vaccines may offer advantages over conventional treatment, although much work still needs to be done.