P08-06SIGNIFICANTLY HIGHER RISK FOR HIGH-GRADE CERVICAL LESIONS IN FOLLOW-UP BIOPSY ASSOCIATED WITH POSITIVE APTIMA HPV TESTS THAN COBAS TESTS

08. HPV testing
Y. Ge 1, P. Christensen 1, E. Luna 2, D. Armylagos 2, J. Xu 3, M. Schwartz 4, D. Mody 1.
1Houston Methodist Hospital and Weill Medical College of Cornell University (United States), 2BioReference Laboratories (United States), 3Center for Biostatistics, Houston Methodist Hospital Research Institute (United States), 4Houston Methodist Hospital (United States)

Background / Objectives

HPV tests and genotyping have been used in clinical risk assessment. The purpose of this study was to analyze the performance of two common HPV testing platforms in risk evaluation for high-grade cervical lesions (HSIL+, including CIN2 and above).


Methods

Between January 1 and December 31, 2016, 4732 Pap tests with biopsy confirmation were analyzed along with HPV tests performed on Cobas (Cobas 4800 system, Roche Molecular Diagnostics, Pleasanton, CA) or Aptima (Hologic/Gen-Probe, San Diego, CA) platforms. 


Results

There were 4105 and 627 Pap samples tested on Cobas and Aptima platforms, respectively. Both platforms were highly sensitive for biopsy-confirmed HSIL+ lesions (98% and 96% for Cobas and Aptima, respectively, p=0.51). However, Cobas HPV testing showed significantly higher positive rates for diagnosis of benign (86% vs. 56%) and LSIL (90.5% vs. 66.4%) on biopsy as compared to Aptima. As a result, Aptima HPV testing had a significantly higher specificity for HSIL+ than Cobas (38% vs. 12%, p<0.0001). Overall, performance of Aptima platform was superior to Cobas in detecting biopsy-confirmed HSIL+ due to providing significantly higher positive predictive value (25% vs. 16%, p<0.0001) and overall accuracy (48% vs. 24%, p<0.0001). Aptima hrHPV genotyping also demonstrated a significantly higher specificity for HSIL+ on biopsy than Cobas genotyping measured by either HPV 16/18/or45 (87% vs 73%, p<0.0001) or non-16/18/or45 (51% vs. 39%, p<0.0001) with comparable sensitivity (50% vs. 52%, p=0.68 and 47% vs. 46%, p=0.92, respectively). 


Conclusion

Despite Aptima and Cobas platforms offer comparably high sensitive tests for high-grade lesions, Aptima HPV test and genotyping demonstrated significantly higher specificity and positive predictive value than Cobas testing for biopsy-confirmed HSIL+ lesions. The considerable difference may be related to the significant increase in E6/E7 expression following HPV DNA integration in HSIL+ lesions. The significantly higher specificity and overall accuracy of Aptima test and genotyping for HSIL+ lesions may be useful in clinical risk management by identifying high-risk populations.


References