Exploring endometrial cancer in premenopausal women—A nationwide PremEnCa cohort study
Abstract
Introduction
An increased incidence of endometrial cancer has been noted, especially in premenopausal women in countries with rapid socioeconomic transition. In one of the largest patient cohorts of women ≤50 years, with manually validated register data, we aim to examine the pattern of disease of endometrial cancer and to evaluate the prognosis according to tumor and patient characteristics, focusing on body mass index.
Material and Methods
This is a nationwide population‐based study on women ≤50 years with endometrial cancer, 2010–2021, using data from Swedish registries complemented by the reviewing of medical records. Overall survival and disease‐free survival were calculated by the Kaplan–Meier method and the log‐rank test. Multivariable regression analyses were performed.
Results
Of the total endometrial cancer cohort, 797 (5%) patients were ≤50 years of age (the PremEnCa cohort) with 0.9% under 40 years of age. Women ≤50 years of age had a higher prevalence of stage IA and endometrioid histology than older women. Among women ≤50 years of age, 46% met the criteria for obesity. No associations between socioeconomic factors and stage at diagnosis were found. Notably, women with lower Body Mass Index <20, had a higher proportion of non‐endometrioid histology and higher stage of disease at the time of diagnosis. Median follow‐up time was 4.2 (IOR 1.9–5.4) years. The recurrence rate was 6.1% in the PremEnCa cohort during the follow‐up period, and the 5‐year overall survival was 94.6% (95% CI: 92.6–96.0) for endometrioid and 68.5% (95% CI: 51.1–80.8) for non‐endometrioid endometrial cancer. Only 36 of the 74 deaths were caused by endometrial cancer. In adjusted analyses for disease‐free survival, non‐endometrioid histology and International Federation of Gynecology and Obstetrics (FIGO) stage were associated with worse prognosis.
Conclusions
Endometrial cancer in premenopausal women is very rare and is associated with an excellent prognosis. Histology and FIGO stage were the strongest prognostic factors. Half of the deaths were due to other causes, which emphasizes the importance of focusing on general health aspects in this young endometrial cancer population.