Nationwide audit of cervical cancer screening reveals unsatisfactory triage strategies and trends over time in incidence among cytology negative women

Regular audits are essential for monitoring and evaluation of cervical screening. We audited the Swedish cervical screening program during the transition to HPV-based screening using a registry-based cohort design. In total, 5689 consecutive, confirmed cases of invasive cervical cancer between 2012 and 2022 were retrieved from the Swedish Quality Register for Gynecological Cancer. Their screening history, screening status, invitations to cervical screening, all diagnoses in screening cytology and HPV genotypes were retrieved from the Swedish National Cervical Screening Registry. Furthermore, all cancer cases during 2018-2022 were classified according to their screening history and the age-standardized cervical cancer incidence rate stratified by screening history and calendar year was calculated among the cohort of all women in Sweden ages 29-84. Non-participation remains the main process related history with high risk of cancer (cervical cancer incidence rate, IR, among non-attenders was 33.9 95% confidence intervals, 95% CI, 28.2-39.5 per 100,000 person-years, /100,000PY, representing 31% of cases in 2022). The cervical cancer IR after negative cytology increased with calendar time (IR = 5.5 95% CI, 4.1-6.8/100,000PY in 2012 and 11.5 8.1-14.9/100,000PY in 2022) and was high after a positive HPV test followed by negative cytology triage (IR = 56.7 39.9-73.6 in 2022). In conclusion, this comprehensive audit has identified a decreasing protection by the screening test under discontinuation (cytology) and that the performance as a triage test after HPV-testing is unsatisfactory.