Role of HPV genotyping in risk assessment among cytology diagnosis categories: Analysis of 4562 cases with cytology-HPV cotesting and follow-up biopsies

Objective Human papilloma virus (HPV) detection and genotyping are increasingly used in clinical risk assessment. We aimed to analyze HPV genotyping performance in risk stratification among cytology diagnosis categories. Methods Between January 1, 2015 and December 31, 2016, 4562 cases with cytology-HPV co-testing and biopsy follow-up were identified. HPV tests were performed on Cobas (n=3959) or Aptima (n=603) platforms. Of the biopsies, 669 demonstrated high-grade squamous intraepithelial lesions or worse. Results Pooled high-risk HPV testing had high overall sensitivity (97%) but low specificity (20%) and positive predictive value (20%) for biopsy-confirmed high-grade squamous intraepithelial lesions or worse. HPV16/18 genotyping had considerably improved specificity (81%) and positive predictve value (35%) in predicting high-grade squamous intraepithelial lesions or worse, especially in atypical squamous cells of undetermined significance and low-grade squamous intraepithelial lesion categories. Significantly more biopsy-confirmed high-grade squamous intraepithelial lesions or worse were detected by Aptima than Cobas testing, as measured by HPV16/18 (48% vs 33%, p<0.001), non-16/18 high-risk HPV (18% vs 13%, p=0.029), or all high-risk HPV genotypes (27% vs 19%, p<0.001). Aptima genotyping showed a significantly higher positive predictive value than Cobas genotyping for biopsy-confirmed high-grade squamous intraepithelial lesions or worse in the atypical squamous cells of undetermined significance category (47% vs 23%, p<0.05). Conclusions HPV genotyping was sensitive for biopsy-confirmed high-grade squamous intraepithelial lesions or worse in all cytologic categories, and is particularly valuable in risk evaluation for women with atypical squamous cells of undetermined significance and low-grade squamous intraepithelial lesions. The triaging role was greatly diminished in high-risk lesions (atypical glandular cells, atypical squamous cells, cannot exclude high-grade squamous intraepithelial lesions and high-grade squamous intraepithelial lesions) due to low specificity and positive predictive value. Aptima performance in risk management was superior to Cobas, with significantly higher positive predictive value for biopsy-confirmed high-grade squamous intraepithelial lesions or worse. Our results highlight the importance of careful data interpretation from studies using different HPV testing methods and the need to incorporate HPV E6/E7-mRNA testing into management guidelines.