Impact of changes to cervical screening guidelines on age and interval at which women are tested: Population-based study

Association between HPV vaccination and cervical screening policy changes and cervical cancer incidence and grade-3 cervical intraepithelial neoplasia incidence in England, 2006-2020: a population-based trends analysis

Background

Monitoring trends in diseases after the implementation of new public health interventions or policy changes is crucial for public health planning and surveillance. In this study we look at variations in rates of cervical cancer and grade-3 cervical intraepithelial neoplasia (CIN3) incidence between 2006 and 2020 in England and relate them to predictions based on the changes in HPV vaccination and cervical screening policy.

Methods

Using population-based registry data, we estimated incidence rates and their 95% confidence intervals for cervical cancer and CIN3 by age group and by either year of diagnosis or 1-year birth cohort. Trends were compared over time and across birth cohorts by calculating relative changes with respect to reference time points. We also tested if trends in women offered HPV vaccination were significantly different across outcomes (cervical cancer and CIN3) and age groups. To do this, we used Poisson regression with adjustments for interval censoring, overdispersion and correlation between observations.

Findings

There were 5558 cancers and 164,682 cases of CIN3 from 53.4 million women-years of observation in the age group 20-29.99 years. We found no evidence of increased cervical cancer rates over the age of 26 in cohorts not offered cervical screening until age 24.5 or 25 years. Substantial and increasing reductions in CIN3s and cervical cancers were observed in the cohorts offered HPV vaccination and were consistent with an 80% (95% CI: 72.9%-87.1%) decrease in cervical neoplasia in the routine vaccination group.

Interpretation

Plots against different time scales (e.g., calendar year and date of birth) may provide important insights that could otherwise be missed. Our findings are consistent with a sustained high effectiveness of the HPV immunization programme as the catch-up vaccination cohorts age.

Funding

Cancer Research UK.

Managing an extension of screening intervals: Avoiding boom and bust in health care workloads

Extending screening intervals in ongoing cancer screening programmes can lead to challenging year-on-year variations in the number of screening tests. We explored how such variation could be diminished with a managed transition to the extended interval. We defined three extension scenarios: immediate extension for the entire target population; stepped transition by birth cohort; and gradual transition by reducing the number of available screening appointments. These were compared to a situation in which the interval remains unchanged in a demographic model covering a 15-year period. The model was populated with observed parameters from England, a real-world setting recommending cervical screening with 3-year intervals at age 25-49 and 5-year intervals at age 50-64. Informed by typical changes currently considered by several European programmes including the programme in England, we explored the effect on screening test numbers of an extension of the 3-year interval to 5 years for women younger than 50. All three extension scenarios resulted in similar cumulative numbers of screening tests, which were about 30% lower compared to a situation in which the interval would remain unchanged. However, the year-on-year variation in the number of screening tests varied between the scenarios. This variation was around 4-fold for the immediate scenario. In the stepped scenario, the yearly numbers could differ by around 20%, whereas in the gradual scenario they were virtually constant. A managed interval extension, transitioning different groups of the target population at different times, can substantially reduce the yearly variation in screening workload without increasing the total number of screening tests in the long term.

Non-speculum clinician-taken samples for human papillomavirus testing: a cross-sectional study in older women

BACKGROUND

Cervical cancer incidence and mortality are high in women aged ≥65 years, despite the disease being preventable by screening. Speculum-based screening can become more uncomfortable after the menopause.

AIM

To examine test performance and acceptability of human papillomavirus (HPV) testing on clinician-collected vaginal samples without a speculum (non-speculum).

DESIGN AND SETTING

Cross-sectional study in 11 GP practices and four colposcopy clinics in London, UK, between August 2017 and January 2019.

METHOD

Non-speculum and conventional (speculum) samples were collected from women aged ≥50 years attending for a colposcopy (following a speculum HPV-positive screening result) or women aged ≥35 years (with confirmed cervical intraepithelial neoplasia (CIN) 2+), and women aged 50-64 years attending routine screening. Sensitivity to CIN2+ was assessed among women with confirmed CIN2+ (colposcopy). Specificity to HPV relative to speculum sampling and overall concordance was assessed among women with negative cytology (routine screening).

RESULTS

The sensitivity of non-speculum sampling for detecting CIN2+ was 83.3% (95% confidence interval [CI] = 60.8 to 94.2) (n = 15/18). There was complete concordance among women with positive CIN2+ who had a speculum sample ≤91 days prior to the non-speculum sample (n = 12). Among 204 women with negative cytology, the specificity to HPV was 96.4% (95% CI = 92.7 to 98.5), with 96.6% concordant results (κ 72.4%). Seventy-one percent (n = 120/170) of women preferred a non-speculum sample for their next screen.

CONCLUSION

HPV testing on non-speculum clinician-taken samples is a viable approach that warrants further exploration in larger studies. Overall test performance was broadly comparable with that of self-sampling.