Cervical cancer incidence in Denmark: Disentangling determinants of time trend

Abstract

Cervical cancer is a preventable disease. Nevertheless, stagnation has been seen in incidence rates also in countries with well-functioning healthcare. On this basis, we investigated associations between control interventions and changes in cervical cancer incidence in Denmark from 2009 to 2022. Data on human papillomavirus (HPV)-vaccination were retrieved from Staten's Serum Institute; on screening recommendations from Danish Health Authority, on screening performance from Danish Quality Database for Cervical Screening; and on cervical cancer incidence from Nordcan and Danish Cancer Register. We reported coverage with HPV vaccination (1+ dose); coverage with cervical cell samples; number of women with primary HPV tests; proportion of non-normal cell samples without timely follow-up; number of conizations; and cervical cancer incidence rates. In 2022, all women aged ≤29 had been offered childhood HPV vaccination with coverage of 80%-90%. By 2020-2022, the cervical cancer incidence rate in women aged 20-29 was 3 per 100,000; at level of disease elimination. In 2017, women aged 70+ were offered a one-time HPV screening, and by 2020-2022, the old-age peak in cervical cancer incidence had largely disappeared. From 2009 to 2022, proportion of non-normal cell samples without timely follow-up decreased from 20% to 10%, and conventional cytology was largely replaced by SurePath liquid-based cytology; these factors could explain the steady decrease in cervical cancer incidence rate. Implementation of primary HPV screening in women aged 30-59 in 2021 was reflected in a, probably temporary, increase in the 2022 cervical cancer incidence rate. In conclusion, combined interventions with childhood HPV vaccination; one-time HPV screening of elderly women; and better management of screening broke previous stagnation in cervical cancer incidence rate.

Keywords: cancer incidence rate; cervical cancer; human papillomavirus vaccination; screening time trend.