Prognostic and diagnostic validity of p16/Ki-67, HPV E6/E7 mRNA, and HPV DNA in women with ASCUS: A follow-up study

Abstract

Background: We evaluated the prognostic and diagnostic ability of p16/Ki-67 immunocytochemistry, HPV E6/E7 mRNA testing and HPV DNA assay in triaging ASCUS to find a way to manage cervical lesions more effectively. Methods: We conducted a prospective study through follow-up. The detection methods of the three factors: p16/Ki-67 immunocytochemistry conducted by using the CINtec® Plus Kit, E6/E7 mRNA testing by QuantiVirus®HPV E6/E7 mRNA assay and DNA by Hybrid Capture 2 assay. Results: One hundred three women with ASCUS satisfied requirements and completed the entire follow-up process. All CIN2+ occurred in women who were mRNA positive at baseline, none in mRNA negative. 100% (6/6) patients with CIN2+ were HPV DNA assay positive, 100% (6/6) were HPV E6/E7 mRNA testing positive and 50.0% (3/6) were p16/Ki-67 immunocytochemistry positive. The risk ratio of E6/E7 mRNA test was 57.306 (95% CI 0.077-42,400.545). For endpoint of CIN2+, the sensitivity between HPV DNA assay and HPV E6/E7 mRNA testing is no statistical difference, but statistical difference exists between HPV E6/E7 mRNA testing vs. p16/Ki-67 immunocytochemistry (χ 2 = 5.718, P = 0.023) and HPV DNA assay vs. p16/Ki-67 immunocytochemistry (χ 2 = 5.718, P = 0.023). The specificity of E6/E7 mRNA testing, p16/Ki-67 and DNA assay in triaging ASCUS was 44.33, 75.26 and 11.34% respectively and is all statistical difference (χ 2 = 26.277, P < 0.001(HPV DNA assay vs. HPV E6/E7 mRNA testing), χ 2 = 19.297, P < 0.001(HPV E6/E7 mRNA testing vs. p16/Ki-67 immunocytochemistry), χ 2 = 80.707, P < 0.001(HPV DNA assay vs. p16/Ki-67 immunocytochemistry). The expression level of 2097.09 copies/ml was the optimal cut-off value for HPV E6/E7 mRNA testing to diagnose CIN2+, the sensitivity and specificity was 61.1 and 68.2%. Conclusions: High expression of HPV E6/E7 mRNA could be a good candidate as a diagnostic biomarker to triage ASCUS superseding HPV DNA. p16/Ki-67 immunocytochemistry is suggested to be a good tool to triage ASCUS, but it reduced the sensitivity of diagnosis when improves the diagnostic specificity.