Objective: This study aimed to investigate risk factors of progression to endometrial cancer (EC) in women with non-atypical and atypical endometrial hyperplasia (EH).
Methods: The data of 62,333 women with EH diagnostic codes from 2007 to 2018 were sourced from the Korean Health Insurance Review and Assessment Service databases. The data from 11,525 women with non-atypical EH and 2,219 women with atypical EH who met the selection criteria were extracted for analysis.
Results: Risk of EC in women with EH decreased in 40-49 year olds compared to other ages (non-atypical EH: [≤39 vs. 40-49 years] HR, 0.557; 95% CI, 0.439-0.708; P<0.001; [≤39 vs. ≥50 years] P = 0.739; atypical EH: [≤39 vs. 40-49 years] HR, 0.391; 95% CI, 0.229-0.670; P = 0.001; [≤39 vs. ≥50 years] P = 0.712). Risk of EC increased with increase in number of follow-up biopsies in women with non-atypical EH (1 biopsy: HR, 1.835; 95% CI, 1.282-2.629; P = 0.001; ≥2 biopsies: HR, 3.644; 95% CI, 2.585-5.317; P<0.001) and in women receiving ≥2 follow-up biopsies with atypical EH (HR, 3.827; 95% CI, 1.924-7.612; P = 0.001). Time of progression to EC decreased in women ≥50 years old with non-atypical EH compared to other ages (P = 0.004) and showed no differences among ages in women with atypical EH (P = 0.576). Progestational agents were a protective factor for EC in women with non-atypical EH (HR, 0.703; 95% CI, 0.565-0.876; P = 0.002).
Conclusions: In this claim data analysis, women ≤39 and ≥50 years old with EH were at a high risk for progression to EC, and repeat follow-up biopsy after a diagnosis of EH increased detection of EC. Progestational agents were an effective modality to prevent EC in women with non-atypical EH.