Management of low-grade cervical cytology in young women. Cohort study from Denmark

OBJECTIVE

Cytology findings of atypical squamous cells of unknown significance (ASCUS) or low-grade squamous intraepithelial lesion (LSIL) are common among women under 30, but evidence on best management strategy is insufficient. We therefore investigated how different management strategies used in Denmark influenced biopsy rates and detection of cervical intraepithelial neoplasia (CIN).

METHODS

Register-based cohort study including Danish women aged less than 30 years and born 1980-95, with ASCUS/LSIL as their first abnormal cervical cytology in 2008-16. Rates and relative risks (RR) of biopsy and detection of CIN3+, CIN2 and < CIN2 during two years follow-up were compared between women referred directly to colposcopy after ASCUS/LSIL or undergoing additional testing, including mRNA or DNA test for high risk HPV or repeat cytology.

RESULTS

19,946 women with ASCUS and 19,825 with LSIL were included in the study of whom 92% had adequate information about follow-up. Among women referred directly to biopsy, CIN3+ was detected among 21%, CIN2 in 17%, while 62% had < CIN2. Repeating cytology after 6 months reduced the biopsy rate to 44% of which 53% had < CIN2. Biopsy rates with HPV test were 67% for DNA test, 77% with 14-type mRNA test and 58% with 5-type mRNA test. The detection of CIN3+ was somewhat higher, between 13% and 14% for the three HPV tests vs. 11% with repeat cytology. However, the detection of < CIN2 (not indicating treatment) also increased with RR 2.11 (95% CI 2.01-2.21) for 14-type mRNA test, 1.35 (95% CI 1.29-1.41) for 5-type mRNA test, and 1.86 (95% CI 1.76-1.97) with HPV DNA test.

CONCLUSIONS

The choice of management strategy influences both the detection rate for severe lesions (CIN3+) and the proportion of women followed up for potentially insignificant findings.

High-grade cervical lesions after vaccination against human papillomavirus: A Danish cohort study

Introduction

It is pertinent to evaluate the impact of vaccination against human papillomavirus (HPV) in real life. The aim of the study was to evaluate the real‐life impact of HPV vaccination in the first birth cohort of Danish women offered free HPV vaccination as girls and invited to screening at the age of 23 years.

Material and methods

Women born in 1993 were offered free HPV vaccination at the age of 15 years but women born in 1983 have never been offered free HPV vaccination. We followed these two birth cohorts for 10 years from the age of 15 to after their first invitation to screening, and compared the risk of high‐grade cervical intraepithelial neoplasia (CIN). Data were obtained from Danish national health registers.

Results

Vaccination coverage was 91% in the 1993 birth cohort and <0.1% in the 1983 cohort. Screening coverage was close to 80% in both cohorts. CIN2+ was detected in 4% of the 15 748 screened women born in 1983 and in 3% of the 19 951 screened women born in 1993. The risk of high‐grade CIN was reduced by about 30% in the 1993 cohort compared with the 1983 cohort; for CIN2+ relative risk 0.74 (95% CI 0.66‐0.82) and for CIN3+ relative risk 0.68 (95% CI 0.58‐0.79).

Conclusions

This study investigated the real‐life impact of quadrivalent HPV vaccination by comparing a cohort of women offered HPV vaccination with a cohort of women not offered HPV vaccination. The observed decrease in the detection of high‐grade cervical lesions following HPV vaccination is in line with results from the randomized trials and has important implications for future cervical screening of HPV vaccinated cohorts.

Impact of HPV vaccination on outcome of cervical cytology screening in Denmark-A register-based cohort study

4vHPV vaccination has been tested in randomized controlled trials under almost ideal conditions, and studies of real-life use have compared outcome between vaccinated and unvaccinated women from the same birth cohort and mostly before screening age. Here we present the first-to our knowledge-evaluation of the impact of the 4vHPV vaccination in real life without selection bias in the reported data. The study has been carried out by comparing the results after first cervical screening between an HPV-vaccinated and an unvaccinated birth cohort, consisting of women born in Denmark in 1993 and 1983, respectively. Cytology data covering an 8-year period, from the age of 15 (age of HPV-vaccination) to age 23 (age of invitation to first cervical screening), were retrieved from the Danish National Pathology Register. Abnormal cytology, defined as atypical squamous cell of undetermined significance and worse (ASCUS+) was detected in 9.4% of women born in 1993 as compared with 9.0% of women born in 1983; RR = 1.04 (95% CI 0.96-1.12), p = .29. Detection of high-grade squamous intraepithelial lesion (HSIL) was statistically significantly lower in the 1993 than in the 1983 cohort, RR = 0.6 (95% CI 0.5-0.7), p < .0001, while the opposite pattern was seen for ASCUS RR = 1.4 (95% CI 1.2-1.6), p < .0001. The decrease in HSIL means that more women can be spared referral for colposcopy and biopsy. The increase of ASCUS could be explained by transition from conventional to liquid-based cytology, but this observation requires further monitoring.

Danish method study on cervical screening in women offered HPV vaccination as girls (Trial23): a study protocol

INTRODUCTION

The first birth cohorts of women offered human papillomavirus (HPV) vaccination as girls are now entering cervical screening. However, there is no international consensus on how to screen HPV vaccinated women. These women are better protected against cervical cancer and could therefore be offered less intensive screening. Primary HPV testing is more sensitive than cytology, allowing for a longer screening interval. The aim of Trial23 is to investigate if primary HPV testing with cytology triage of HPV positive samples is a reasonable screening scheme for women offered HPV vaccination as girls.

METHODS

Trial23 is a method study embedded in the existing cervical screening programme in four out of five Danish regions. Without affecting the screening programme, women born in 1994 are randomised to present screening with liquid-based cytology every third year (present programme arm) or present screening plus an HPV test (HPV arm). The study started 1 February 2017 and will run over three screening rounds corresponding to 7-8 years.

ANALYSES

The primary endpoint is cervical intraepithelial neoplasia grade 3 or above. The trial is undertaken as a non-inferiority study including intention-to-treat and per-protocol analyses. The potential effect of primary HPV screening with a 6-year interval will be calculated from the observed data.

ETHICS AND DISSEMINATION

The study protocol has been submitted to the ethical committee and deemed a method study. All women are screened according to routine guidelines. The study will contribute new evidence on the future screening of HPV vaccinated birth cohorts of women. All results will be published in open-access journal.

TRIAL REGISTRATION

NCT03049553; Pre-results.

Burden of HPV-caused cancers in Denmark and the potential effect of HPV-vaccination

BACKGROUND

Denmark is one of the countries where Human papillomavirus (HPV)-vaccination at present includes only girls. However, the burden of HPV-related cancer in men is increasing, which would argue for gender-neutral vaccination. The aim of this study was to examine the burden of HPV-caused cancers in women and men, and to evaluate the potential of HPV-vaccination in cancer control.

METHODS

Data were retrieved from the literature on population prevalence of high risk (HR) HPV, on HR HPV-prevalence and genotypes in HPV-related cancers, and on number of cytology samples in cervical screening. Data on annual biopsies and conisations were retrieved from the Danish National Health Service Register and the Danish National Patient Register. Incidences of HPV-related cancers in Denmark were extracted from NORDCAN. Number of HPV-caused cancers was calculated from number of HPV-related cancers and the proportion known to be caused by high-risk (HR) HPV.

RESULTS

In cross-sectional surveys in Denmark, one fifth of women and almost one third of men were found to be positive for HR HPV. Per year, 548 HPV-caused cancer cases were diagnosed in women and 234 in men, and twice as many cancers in women as in men were preventable with HPV vaccination. However, including screening prevented cervical cancers, the burden of cancers caused by HPV-infection would be 1300-2000 in women as compared to 234 in men.

CONCLUSION

Taking screening prevented cervical cancers into account, the cancer control potential of HPV-vaccination is considerably higher in women than in men. HPV-vaccination could reduce the burden of screening on women and on health care resources.