Risk of high-grade cervical intra-epithelial neoplasia based on cytology and high-risk HPV testing at baseline and at 6-months.

Adding a test for high-risk human papillomavirus (hrHPV) to cytological screening enhances the detection of high-grade cervical intraepithelial neoplasia (>or=CIN2), but data are required that enable long-term evaluation of screening. We investigated the >or=CIN2 risk for women participating in population-based screening as a function of hrHPV and cytology testing results at baseline and at 6 months. We included 2,193 women aged 30-60 years participating in a population-based screening trial who received colposcopy or a repeat testing advice at baseline. The main endpoint was histologically confirmed >or=CIN2 diagnosed within 36 months. hrHPV testing was more sensitive than cytology for >or=CIN2 (relative sensitivity 1.4, 95%CI: 1.3-1.5; absolute sensitivity 94.1 and 68.0%, respectively). The 18-month >or=CIN2 risks in women with a hrHPV-positive smear and in women with abnormal cytology were similar (relative risk 0.9, 95%CI: 0.8-1.1). Women with HPV16 and/or HPV18 had a higher >or=CIN2 risk than other hrHPV-positive women irrespective of the cytological grade. Repeat testing showed that both cytological regression and viral clearance were strongly associated with a decrease in >or=CIN2 risk. Notably, women who had a double negative repeat test at 6 months had a >or=CIN2 risk of only 0.2% (95%CI: 0.0-1.1) and hrHPV-negative women with baseline borderline or mild dyskaryosis and normal cytology at 6 months had a >or=CIN2 risk of 0% (95%CI: 0.0-0.8). Using hrHPV and/or cytology testing, risk of >or=CIN2 can be assessed more accurately by repeat testing than single visit testing. Hence, when hrHPV testing is implemented, patient management with repeat testing is a promising strategy to control the number of referrals for colposcopy.