Sociodemographic disparities in stage-specific incidences of endometrial cancer: a registry-based study in West Sweden, 1995-2016.

Background: For a few types of cancer, lower socioeconomic status (SES) is associated with higher incidence, and for even more cancer types it is associated with having a less favorable tumor stage at diagnosis. For endometrial cancer (EC), however, there is no clear evidence of such associations with SES. There is a need for analysis of sociodemographic disparities in EC incidences according to stage at diagnosis, which may provide support for trying to improve early detection of EC. Material and methods: Stage-specific incidences of endometrioid and non-endometrioid endometrial carcinomas [EECs (∼90% of all EC cases) and NECs (∼10%)] were analyzed for the population of the Western Swedish Healthcare Region, taking into account year (1995-2016), age, educational level (low, intermediate and high), and immigrant status (Swedish-born, foreign-born). All EC cases were identified and data were obtained from population-based registries. Results: Stage distribution of diagnosed EECs differed significantly according to the educational level of patients who were aged between 50 and 74 years at diagnosis, but not in the case of younger or older patients. An analysis based on 3113 EEC cases aged 50-74 years at diagnosis revealed marked disparities in the stage-II to stage-IV EEC incidences but not in the stage-I EEC incidence. Compared to women with a high level of education, the incidence rate ratios of stage-I, stage-II and stage-III and -IV EEC in women with a low level of education were 1.00 (95% CI: 0.90-1.12), 1.65 (1.13-2.42), and 1.82 (1.33-2.49), respectively. For NEC, we found no such association. Conclusions: Elevated incidences of stage-II to stage-IV EEC in 50- to 74-year-old women with a low level of education suggest that there should be targeted health service trials aimed at improving awareness of EC. Well-targeted EC awareness programs might lead to considerable health benefits.