Clinical value of fully automated p16/Ki-67 dual staining in the triage of HPV-positive women in the Norwegian Cervical Cancer Screening Program.

BACKGROUND

More accurate biomarkers in cervical cytology screening could reduce the number of women unnecessarily referred for biopsy. This study investigated the ability of p16/Ki-67 dual staining to predict high-grade cervical intraepithelial neoplasia (CIN) in human papillomavirus (HPV)-positive women from the Norwegian Cervical Cancer Screening Program.

METHODS

Automated p16/Ki-67 dual staining was performed on liquid-based cytology samples from 266 women who were HPV-positive at their secondary screening. At a mean of 184 days after p16/Ki-67 staining, 201 women had a valid staining result and a conclusive follow-up diagnosis (histological diagnosis or HPV-negative diagnosis with normal cytology findings). The sensitivity and specificity for predicting the follow-up diagnosis were compared for cytology, p16/Ki-67 dual staining, and their combination.

RESULTS

Sixty-seven percent of the study sample was p16/Ki-67-positive. The sensitivity of p16/Ki-67 staining for predicting CIN-2/3 was statistically significantly higher than the sensitivity of cytology (0.88 vs 0.79; P = .008), but this was not true for the prediction of CIN-3 (0.94 vs 0.88; P = .23). The specificity of cytology for predicting CIN-3 was significantly higher than the specificity of p16/Ki-67 staining (0.35 vs 0.28; P = .002), but this was not true for CIN-2/3 (0.35 vs 0.31; P = .063). For predicting CIN-2/3 and CIN-3, combination testing gave potentially better sensitivity (0.95 and 0.96, respectively) and better specificity (0.49 and 0.50, respectively).

CONCLUSIONS

In a population of HPV-positive women, p16/Ki-67 dual staining was more sensitive but less specific than cytology for predicting high-grade CIN. The advantage of using both tests in different combinations is the potential for increasing the specificity or sensitivity in comparison with both methods performed individually. Cancer Cytopathol 2017;125:283-291. © 2016 American Cancer Society.