Age-specific trend and birth cohort effect on different histologic types of uterine corpus cancers.

To evaluate the uterine corpus cancer incidence rates, age-specific trends, and birth cohort patterns by different histologic types. We conducted a retrospective cohort study of uterine cancer patients (n = 28,769) of all ages from the National Cancer Registry of Taiwan between 1998 and 2017. We estimated the incidence trends, average annual percent changes (AAPCs), and cancer-specific survival (CSS) rate for the two main subtypes (endometrioid and nonendometrioid) of uterine cancer in Taiwan. During the study period, uterine corpus cancer incidence rates increased over time from 5.3 to 15.21 per 100,000 women. Incidence trends for endometrioid carcinoma increased in all age groups (positive AAPCs > 5% for each age group), and the rise was steeper among women aged 50 years and younger. For nonendometrioid carcinomas, incidence rates increased among women over 50 years. The CSS rate improved among women with stage I (hazard ratio [HR] 0.63, 95% confidence interval [CI] 0.49-0.81) and stage III (HR 0.72, 95% CI 0.58-0.90) endometrioid carcinomas after 2013 compared with those during 2009-2012. However, the CSS rate remained unchanged for nonendometrioid carcinomas. Age, diagnostic period, stage and histologic types were significant factors associated with the 5-year CSS rate. We found that the incidences of both endometrioid and nonendometrioid carcinomas continued to increase among contemporary birth cohorts. Etiologic research is needed to explain the causes of these trends.