Human papillomavirus testing for primary screening of cervical cancer precursors

Our objective was to determine whether the addition of human papillomavirus (HPV) testing to screening cytology improves the detection of cervical cancer precursors. Women of ages 18-69 years underwent conventional Pap cytology and HPV DNA testing in a multicenter study in Newfoundland, Canada. Those with positive cytology and/or HPV and a random sample of those with dual negative results were referred for colposcopy. The study enrolled 2098 women. The relative sensitivity of HPV testing was significantly higher than cytology for all-grade squamous intraepithelial lesions [SILs; 73%; 95% confidence interval (CI), 62-82] and high grade SILs (HSILs; 90%; 95% CI, 74-97) but had lower relative specificity (62% for all-grade SILs and 51% for HSILs) than most cytological cutpoints. The rate of combined correct results for all-grade lesions was higher for HPV testing (68.8%) than for any cytological cutpoint (equivocal, 52.3%; LSILs, 51.6%; HSILs, 44.5%). The combination of HPV and an LSIL cutpoint had a negative predictive value of 68% (95% CI, 52-80) for all SILs and 100% (95% CI, 91-100) for HSILs, while referring for colposcopy only 12% of the women. We concluded that HPV testing in conjunction with cytology improved the screening efficacy of cytology alone and may allow for a more effective and safe primary screening program with increased screening intervals.