Prognostic value of HPV E6/E7 mRNA assay in women with negative colposcopy or CIN1 histology result: a follow-up study

Abstract

Pap test, and especially HPV DNA test, identify a large group of women who do not have any clinically relevant lesions, i.e., CIN2+ (Cervical Intraepithelial Neoplasia grade 2 or worse), but who are at greater risk of getting lesions in the future. The follow up of these women needs new biomarkers with prognostic value. The objective of this study is to evaluate the prognostic value of E6/E7 mRNA over-expression assay (PreTect HPV-Proofer, Norchip) for 5 HR-HPV types (16, 18, 31, 33, and 45) for progression to CIN2+ after a negative colposcopy. This prospective study, conducted at four Italian centres, enrolled 673 women with either a negative colposcopy or a negative or CIN1 histology. The clinical end-point was histological confirmation of CIN2+. Women were classified at baseline according to mRNA results and managed according to local colposcopy protocols. At least one conclusive follow-up test was obtained for 347 women (25 months average lapse since recruitment, range 5-74). Only seven CIN2+ were detected during follow up, three among the 82 women positive for mRNA at baseline, two among the 250 negative (Fisher exact test, p = 0.02), and two among the 12 with an invalid test. Absolute CIN2+ risk was 6.7/1,000 person/years in the whole cohort. The absolute CIN2+ risk was 18.4/1,000 person/years and 3.6/1,000 person/years in mRNA-positive and mRNA-negative women, respectively. In conclusion, E6/E7 mRNA over-expression appears to be a good candidate as a prognostic biomarker to manage HR-HPV DNA-positive women with negative colposcopy or histology, particularly in order to decrease follow-up intensity in those who are negative.