Impact of social disparities and screening attendance on cervical cancer incidence among Danish women, 1987-2016.

Background: For cervical cancer (CC), the implementation of preventive strategies has the potential to make CC occurrence and death largely avoidable. To better understand the factors possibly responsible for the barriers to HPV vaccination and screening, we aimed to examine possible differences in biological and social parameters as well as screening adherence between women with and women without a prior CC diagnosis and according to disease stage. Methods: : Through the Danish Cancer Registry (DCR), women diagnosed with CC in Denmark between 1987 and 2016 were included. These were age- and residence-matched in a 1:5 ratio with controls from the general female population. The study population was sub grouped into a low-stage subpopulation with women with early-stage CC and matched controls and a high-stage subpopulation with women with late-stage CC and matched controls. Biological and social parameters were compared within the subpopulations as well as between low- and high-stage cases. For part of the study population, screening attendance was examined to compare differences in adherence. Results: : Overall, we found that the risk of CC is significantly increased in socially disadvantaged women and not least non-attenders in screening. Interestingly, the high-stage subpopulation was significantly older than the low-stage subpopulation ( p <0.001), and when examining the impact of age further, we found that the risk of getting low-stage CC decreases significantly with increasing age, whereas the risk of getting high-stage CC increases significantly with increasing age. In the screening cohort, significantly less cases than controls were attenders in screening with the most pronounced differences seen in the old subpopulation (women aged 50-64 years) and in the high-stage subpopulation ( p -values all <0.001). Interestingly, when examining the risk of CC for attenders and non-attenders, we demonstrated that many social parameters continue to influence the risk of CC, even in women attending screening. Conclusions: : Older women, socially disadvantaged women, and non-attenders in screening are particularly vulnerable in terms of developing CC, especially high-stage disease. Therefore, improvements in the participating rate in screening as well as a revision of the current screening guidelines are needed.