Efficacy of reflex HPV16/18 genotyping in predicting CIN3/VAIN3 in women with HPV+/Pap- results.

Introduction: Genotyping for human papillomavirus (HPV) types 16/18 has been recommended for women with HPV+/Pap- co-testing results on cervical cancer screening. In this study, we evaluated the efficacy of reflex HPV16/18 genotyping for predicting high-grade cervical and vaginal intraepithelial neoplasia (CIN3/VAIN3) in women who underwent a HPV16/18 genotyping test following HPV+/Pap- co-testing results.

Materials And Methods: We retrospectively reviewed records of 175 women who underwent reflex HPV16/18 genotyping after HPV+/Pap- co-testing results at our institution from 2011 to 2013. The HPV16/18 genotyping results using the Cervista HPV16/18 assay were correlated with follow-up data (ie, 107 biopsy and 68 Pap test) to assess the risk of CIN3/VAIN3.

Results: In 175 women (median age: 51 years), HPV16 and/or 18 were detected in 47 women (26.9%): 36 with HPV16, 9 with HPV18, and 2 with HPV16 and 18. The cumulative incidence of CIN3/VAIN3 was 4.6-fold higher in women with a positive HPV16/18 genotyping result (10.6%) than in women with a negative HPV16/18 result (2.3%) with a statistically significant difference (P = 0.015). The predictive value of reflex HPV16/18 genotyping for CIN3/VAIN3 was 63% (5 out of 8).

Conclusions: A positive reflex HPV16/18 genotyping result predicts a significantly higher risk of CIN3/VAIN3 than a negative reflex 16/18 HPV result, supporting the need for an immediate colposcopy evaluation in these patients. For women with a negative reflex HPV16/18 genotyping result, an annual HPV/Pap cytology co-testing is a reasonable follow-up to predict non-16/18 HPV-associated CIN3/VAIN3.