Knowledge of the HPV status biases cytotechnologists' interpretation of Pap tests originally diagnosed as negative for intraepithelial lesion or malignancy

Abstract

BACKGROUND: Because of cervical cancer screening recommendations and forthcoming first-line human papillomavirus (HPV) screening, many Papanicolaou (Pap) tests will be performed in patients with known concurrent HPV results. This study was designed to evaluate whether knowledge of the HPV status affects cytotechnologists' interpretation of Pap tests. METHODS: A retrospective search of cervical screening Pap tests with known concurrent HPV results provided 250 ThinPrep Pap tests, which were chosen to reflect an atypical rate similar to the rate of the Cleveland Clinic's normal practice. Fifty percent of negative for intraepithelial lesion or malignancy (NILM) and atypical squamous cells of undetermined significance (ASCUS) cases were from patients with positive HPV results. Slides were re-evaluated twice by 8 cytotechnologists blinded to the diagnosis and study purpose. The HPV status was provided for 50% of the cases in the first phase; after a washout period, knowledge of the HPV status for each case was reversed in the second phase. Follow-up information was collected from the medical record. RESULTS: In both phases, there was a significant bias for HPV-positive NILM cases to be upgraded to ASCUS or worse when the HPV-positive status was provided (P