Clinical validation of high risk HPV DNA testing versus ThinPrep cytology for primary cervical cancer screening

Objective(s)To compare the validity of the high risk HPV DNA testing using the hybrid capture II technique (HC-II) to ThinPrep cytology for primary cervical cancer screening.DesignCross sectional pilot study.SettingDepartment of Obstetrics and Gynecology, Taiba Hospital, Sabah Al Salem, Kuwait.MethodsConsecutive 1923 cervical smear samples were taken for ThinPrep cytological screening and hr-HPV DNA testing using HC-II assay. Histological diagnoses were obtained from a total of 426 women who had positive results on screening and a group of women with negative screening and suspicious cervix underwent colposcopy and directed biopsies, and those with cervical precancerous lesions or cancer received appropriate treatment.Main outcome measuresSensitivity, specificity, positive predictive value and negative predictive value of screening methods.ResultsHPV was found positive in 15.5% of cases. 19/22 cases (86.4.1%) with a biopsy diagnosis of CIN2+ had a HC-II positive test. For CIN3, HC-II was positive in all cases (100%). Assuming a similar specificity level, the relative sensitivity of the HC-II test was higher when histologically confirmed high grade lesions (CIN2+ or CIN3+) were observed. HC-II test had the best sensitivity when defining cases as CIN2+ or CIN3+ (98.7% and 100%, respectively). When using the ASCUS+ cytological cutoff, the differences in CIN2+ and CIN3+ sensitivity between HC-II test and ThinPrep cytology were statistically not significant. Specificity of the ThinPrep cytology for any low and high grade histological lesions was clearly >95% when cytological diagnosis LSIL+ cutoff was used and nearly 100% when HSIL+ cutoff was used. All these specificity estimates were high compared with HC-II test. The specificity of the ThinPrep cytology decreased with about 10% when ASCUS+ was the cutoff. At cutoff ASCUS+, specificity of HC-II was comparable or only slightly lower than with ThinPrep ASCUS+ cytology with no statistically significant differences.ConclusionsThinPrep smears and hr-HPV DNA detection by HC-II performed very well with regard to identifying high grade lesions. HPV DNA testing is a promising new technology for cervical cancer prevention and can be used for primary screening in conjunction with cervical cytology for women aged 30 years and older.