Precancerous cervical lesions and HPV genotypes identified in previously unsatisfactory cervical smear tests after inexpensive glacial acetic acid processing

Abstract

Objective To determine the effectiveness of using glacial acetic acid (GAA) to convert unsatisfactory bloody ThinPrep (TP) cervical smear test to satisfactory, and identify associated missed diagnoses and high-risk HPV (hrHPV) genotypes. Methods In a retrospective descriptive cross-sectional analysis, all TP tests performed in Mississippi, USA, 2012–2016, were evaluated for unsatisfactory results owing to blood. Tests that were converted to satisfactory by GAA treatment, and corresponding anomalies and HPV genotypes were identified. Results Among 106 384 TP tests, there were 1460 (1.37%) unsatisfactory results, of which 1442 (98.77%) were converted to satisfactory after GAA treatment. Laboratory preprocessing with GAA increased costs minimally. Precancerous lesions were detected in 166 (11.51%) of 1442 GAA-treated samples, of which 12 (7.2%) were high-grade lesions, 110 (66.3%) were atypical squamous cells of undetermined significance, and 63 (57.3%) tested positive for hrHPV. Of 60 genotyped samples, 39 (65%) had non-HPV16 and non-HPV18. Including mixed infections, 48 (80%) contained less-common hrHPV types, reflecting an unexpected distribution in bloody specimens. Conclusions GAA pretreatment of bloody TP tests would reduce the incidence of unsatisfactory results and missed high-grade lesions, and prevent the cost of repeat tests and delayed treatment. Clinicians without access to GAA should consider HPV testing.