High-risk HPV type-specific clearance rates in cervical screening

We assessed clearance rates of 14 high-risk human papillomavirus (hrHPV) types in hrHPV-positive women with normal cytology and borderline/mild dyskaryosis (BMD) in a population-based cervical screening cohort of 44,102 women. The 6-month hrHPV type-specific clearance rates, that is, clearance of the same type as detected at baseline, in women with normal and BMD smears were 43% (95% confidence interval (CI) 39-47) and 29% (95% CI 24-34), respectively. Corresponding 18-month clearance rates were markedly higher, namely 65% (95% CI 60-69) and 41% (95% CI 36-47), respectively. The lowest clearance rates in women with normal cytology were observed for HPV16, HPV18, HPV31, and HPV33. Significantly reduced 18-month clearance rates at a significance level of 1% were observed for HPV16 (49%, 95% CI 41-59) and HPV31 (50%, 95% CI 39-63) in women with normal cytology, and for HPV16 (19%, 95% CI 12-29) in women with BMD. Among women who did not clear hrHPV, women with HPV16 persistence displayed an increased detection rate of >or=CIN3 (normal P<0.0001; BMD, P=0.005). The type-specific differences in clearance rates indicate the potential value of hrHPV genotyping in screening programs. Our data support close surveillance (i.e. referral directly, or within 6 months) of women with HPV16 and are inconclusive for surveillance of women with HPV18, HPV31, and HPV33. For the other hrHPV-positive women, it seems advisable to adopt a conservative management with a long waiting period, as hrHPV clearance is markedly higher after 18 months than after 6 months and the risk for >or=CIN3 is low.