Age-specific detection of high risk HPV DNA in cytologically normal, computer-imaged ThinPrep Pap samples

Abstract

Objective: Recent cervical cancer screening guidelines for women over age 30 seek to improve the sensitivity of cytology by incorporating high-risk (HR) human papillomavirus (HPV) DNA testing into the screening algorithm, a recommendation based largely on data that utilized the conventional Pap smear and were not stratified by patient age. Data on the rate of HR HPV among women over age 30 undergoing liquid-based Pap test screening are limited. The objective of this study was to determine the rate of HR HPV DNA positivity in women ages 30 and over with a cytologically negative liquid-based Pap test result.

Methods: Consecutive residual ThinPrep Pap samples from women with a cytologically negative result following computer-assisted screening were tested for HR HPV using the Hybrid Capture 2 (HC2) method. All HC2-positive samples were additionally tested with the Linear Array (LA) HPV Genotyping Test.

Results: 1000 cytologically negative specimens from women aged 30 to 45 years (38.9+/-4.7 years) were evaluated. The overall HC2 HR HPV positivity rate in this age group was 3.9% (confidence interval 2.8-5.3%). When stratified by age group, the rate was inversely proportional to age (ages 30-35: 6.7%; 36-40: 3.0%; 41-45: 2.6%) and lower than most previous reports (1-17%). Some of the cases that were positive for HR HPV by HC2 were negative by LA, or showed only low-risk virus.

Conclusions: The HR HPV rates in women ages 30-45 with a cytologically negative, computer-imaged ThinPrep test result are low. If these findings are confirmed in future studies, the added benefit of HPV testing to liquid-based cytology for women ages 30 and over should be critically evaluated.