Human papillomavirus DNA detection in ThinPrep Pap test vials is independent of cytologic sampling of the transformation zone

Abstract

Objective Sampling of the transformation zone (TZ) and endocervical cells (EC) has been widely regarded as a quality indicator in cervical screening programs; however, the significance of a TZ/EC sample (TZ/ECS) in promoting disease detection remains a matter of controversy. Because little data are available on the relationship between TZ/EC sampling and HPV DNA test results, we examined whether or not there is a measurable association between high-risk human papillomavirus (hrHPV) DNA test results and TZ/EC sampling in several thousand women screened in a large academic women's hospital laboratory. Methods 9035 ThinPrep Pap tests (TPPT) reported as negative, LSIL, or HSIL and which also had Hybrid capture 2 (HC2) hrHPV DNA testing over an 18 month period between July 1, 2005 and December 31, 2006 were documented. 8415 negative, 526 LSIL, and 84 HSIL TPPT were included in the study. The age of patients, the presence or absence of a TZ/ECS, and hrHPV DNA test results were noted from CoPath data files. Patients were stratified into 10 year age groups for data analysis. Results An identical 2.8% of Pap negative patients were hrHPV DNA positive in both the 6709 cytology negative patients with a TZ/ECS and the 1706 cytology negative patients without a TZ/ECS. Neither were statistically significant differences noted for hrHPV DNA prevalence in patients with SIL Pap test results from women with and without a TZ/ECS. Conclusions HC2 hrHPV DNA detection in TPPT vials is independent of cytologic sampling of the transformation zone. hrHPV DNA results provide for the first time an available objective basis for risk assessment of patients with no TZ/ECS. The observation that hrHPV DNA test status is independent of presence or absence of a TZ/ECS is consistent with longitudinal studies of Pap negative women with no TZ/ECS which have not found increased disease on follow-up.