Evidence of latent HPV infection in older Danish women with a previous history of cervical dysplasia.

INTRODUCTION: Understanding whether human papillomavirus (HPV) may establish latency in the uterine cervix is important. A better understanding of HPV natural history is useful for clinical counseling of women attending screening and to accurately inform health prevention strategies such as screening and HPV vaccination. We evaluated the extent of latent HPV infections in older women with a history of abnormal cytology. MATERIAL AND METHODS: We conducted a cross-sectional study in Aarhus, Denmark, from March 2013 through April 2015. Women were enrolled if they underwent cervical amputation or total hysterectomy because of benign disease. Prior to surgery, women completed a questionnaire and a cervical smear was collected for HPV testing and morphological assessment. For evaluation of latency (i.e., no evidence of active HPV infection, but HPV detected in the tissue), we selected women with a history of abnormal cervical cytology or histology, as these women were considered at increased risk of harboring a latent infection. Cervical tissue underwent extensive HPV testing using the SPF10-DEIA-LipA25 assay. RESULTS: Of 103 women enrolled, 26 were included in this analysis. Median age was 55 years (interquartile range [IQR] 52-65), and most women were postmenopausal and parous. The median number of sexual partners over the lifetime was six (IQR 3-10), and 85% reported no recent new sexual partner. Five women (19.2%) had evidence of active infection at the time of surgery, and 19 underwent latency evaluation. Of these, a latent infection was detected in 11 (57.9%), with HPV16 being the most prevalent type (50%). Nearly 80% (n = 14) of the 18 women with a history of previous low-grade or high-grade cytology with no treatment had an active or latent HPV infection, with latent infections predominating. HPV was detected in two of the six women with a history of high-grade cytology and subsequent excisional treatment, both as latent infections. CONCLUSIONS: HPV can be detected in cervical tissue specimens without any evidence of an active HPV infection, indicative of a latent, immunologically controlled infection. Modeling studies should consider including a latent state in their model when estimating the appropriate age to stop screening and when evaluating the impact of HPV vaccination.

Implementation of p16/Ki67 dual stain cytology in a Danish routine screening laboratory: Importance of adequate training and experience.

BACKGROUND: Immunocytochemical staining with p16/Ki67 has been suggested as a promising triage biomarker in cervical cancer screening. As dual staining is a subjective method, proper training may be required to ensure safe implementation in routine laboratories and reduce risk of misclassification. We determined concordance between novice evaluators and an expert, stratified by number of slides reviewed at three reading points. METHODS: The study was conducted at the Department of Pathology, Randers, Denmark. Women were eligible if they were aged ≥45, had been enrolled in one of two ongoing clinical studies, and had a dual stain slide available. Dual staining was performed using the CINtec plus assay. Slides were randomly selected from three reading points at which novice evaluators had reviewed <30, ~300, and ≥500 dual stain slides respectively. Level of concordance was estimated using Cohen's Kappa, κ. RESULTS: Of 600 eligible slides, 50 slides were selected for review as recommended by the manufacturer. Median age was 68 years (range: 58-74). Overall concordance was good (κ = 0.68, 95% confidence interval [CI]: 0.60-0.76), with an overall agreement of 84% (95% CI: 70.9%-92.8%). Concordance improved with increasing number of slides reviewed at a given reading point, from a moderate concordance (κ = 0.47, 95% CI: 0.05-0.90) after reviewing <30 slides to a good concordance (κ = 0.66, 95% CI: 0.20-0.88) and a very good concordance (κ = 0.88, 95% CI: 0.66-1.00) after reviewing ~300 and ≥500 slides, respectively. CONCLUSIONS: When interpreting dual stain slides from older women, concordance increased slightly as novice evaluators received more training and experience. Although further evaluation is warranted, these findings indicate that a significant amount of training and experience of novice evaluators may be needed to ensure accurate dual stain interpretation in this age group. Future studies should accurately describe training and experience of evaluators to enable a better comparison of concordance and diagnostic accuracy across studies. TRIAL REGISTRATION: NCT04114968 and NCT04298957.