Triaging HPV-Positive Cervical Samples with p16 and Ki-67 Dual Stained Cytology within an Organized Screening Program-A Prospective Observational Study from Western Norway.

The implementation of high-risk human papillomavirus testing (hrHPV testing) as a screening method in substitute for cytology has evoked the need for more sensitive and less objective tests for the triage of HPV-positive women. In a cohort of 1763 HPV-positive women, the potential of immunocytochemical p16 and Ki-67 dual staining as compared to cytology, alone or in combination with HPV partial genotyping, was tested for triage of women attending a cervical cancer screening program. Performance was measured using sensitivity, specificity, and positive and negative predictive values. Comparisons were assessed using logistic regression models and the McNemar test. Dual staining was evaluated in a prospectively collected study cohort of 1763 HPV-screened women. For triage of CIN2+ and CIN3+, NPV and sensitivity, 91.8% and 94.2% versus 87.9% and 89.7%, respectively, were significantly higher using dual staining together with HPV 16/18 positive, as compared to cytology (p < 0.001). The specificities, however, were lower for dual staining as compared to cytology. Conclusions: Dual staining is safer for decision-making regarding HPV-positive women's need for follow-up with colposcopy and biopsy, as compared to cytology.

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.

Quality assurance of human papillomavirus (HPV) testing in the implementation of HPV primary screening in Norway: an inter-laboratory reproducibility study.

BACKGROUND: Human papillomavirus (HPV) testing as primary screening for cervical cancer is currently being implemented in Norway in a randomized controlled fashion, involving three laboratories. As part of the quality assurance programme of the implementation, an evaluation of the inter-laboratory reproducibility of the HPV test was initiated, to ensure satisfactory HPV test reliability in all three laboratories. METHODS: The HPV test used is the cobas 4800 HPV Test, detecting 14 high-risk types with individual HPV genotype results for HPV16 and HPV18. In addition to the three laboratories involved in the implementation, the Norwegian HPV reference laboratory was included as a fourth comparative laboratory. A stratified sample of 500 cervical liquid based cytology (LBC) samples was used in the evaluation, with an aim towards a high-risk HPV positivity of ~25%. Samples were collected at one laboratory, anonymized, aliquoted, and distributed to the other laboratories. RESULTS: Comparison of the test results of all four laboratories revealed a 95.6% agreement, an 86.3% positive agreement and a kappa value of 0.94 (95% CI 0.92-0.97). For negative cytology specimens, there was a 95.8% overall agreement, a 67.4% positive agreement, and a kappa value of 0.88 (95% CI 0.80-0.93). For abnormal cytology specimens, there was a 95.8% overall agreement, a 95.5% positive agreement, and a kappa value of 0.86 (95% CI 0.71-0.97). CONCLUSIONS: The study showed a high inter-laboratory reproducibility of HPV testing, implying satisfactory user performance and reliability in the laboratories involved in the implementation project. This is important knowledge and we recommend similar studies always to be performed prior to the introduction of new screening routines.