A population of 1136 HPV DNA-HR positive women: expression of p16(INK4a)/Ki67 Dual-Stain Cytology and cytological diagnosis. Histological correlations and cytological follow up.

OBJECTIVE

The objectives of this study were to evaluate, in a selected HR-HPV positive population, the clinical performance of the p16/ki67 immunostaining in all the cytological diagnoses, as a reflex test of triage HPV-cytology, and assess the usefulness of p16/ki67-staining to classify CIN1 according to its risk of progression/regression in order to plan a personalized follow-up.

METHODS

Our analysis was in consecutive cases of 1136 women aged 25-64 years, asymptomatic, HR-HPV DNA HC2 tested positive in a HPV-screening program, from February to December 2011. All the women had a cervical sample, in the Thin Prep, used for cytological diagnosis and for pI6/Ki67 dual- staining. Histological correlations were 442. We studied the follow-up of two years of 387 cases, especially the biological behaviour of 316 low-grade lesions.

RESULTS

pI6/Ki67 dual-staining increases the VPP CIN2+ and NPV CIN2+, especially in atrophy/dystrophy, in ASC-US and LSIL. In follow-up of 387 cases, 71 CIN2+ and 316 CIN1, 69 CIN2+, after surgical treatment, had a negative follow up; two cases of CIN2 (p16/ki67-) without invasive treatments, had a spontaneous regression. Among the 316 CIN1, progression was observed in 10 women (4 pI6/Ki67 + and 6 pI6/Ki67 -); regression in 260 women (64 p16/Ki67 + and 196 p16/Ki67-); 46 women had a persistent LSIL (9 pI6/Ki67 + and 37 p16/Ki67-). It seems no significant differences in the biological behaviour in relation to the expression of the two biomarkers.

CONCLUSIONS

pI6/Ki67 immunostaining increases sensitivity of cytology in some diagnostic categories. After follow up of two years, a personalized and adequate treatment does not seem still possible. Further studies and trials are required to improve the management of the cervical lesions in HPV-based screening strategies.