The association between endometrial cancer and subsequent diabetic retinopathy severity

Objective: The endometrial cancer is a disorder with elevated oxidative stress. The high oxidative stress resulting from hyperglycemia can lead to diabetic retinopathy (DR) development which is a complication of type 2 diabetes mellitus. Accordingly, we aim to evaluate the potential relationship between the endometrial cancer and following DR development. Methods: A retrospective cohort study was conducted using the National Health Insurance Research Database (NHIRD) of Taiwan. Individuals diagnosed with endometrial cancer were matched to the non-endometrial cancer patients in a 1:4 ratio. The major outcomes are the presence of DR, diabetic macular edema (DME) and proliferative diabetic retinopathy (PDR) according to diagnostic codes. Cox proportional hazard regression was used to show the adjusted hazard ratio (aHR) with 95% confidence interval (CI) of major outcomes between groups. Results: There were 99 (2.3%), 20 (0.5%), and 14 (0.3%) cases with DR, DME and PDR in the endometrial cancer group, respectively. Another 303 (1.8%), 35 (0.2%), and 27 (0.2%) with DR, DME and PDR were observed in the control group, respectively. The endometrial cancer group revealed a significantly higher incidence of DR compared with the control group (aHR 1.51, 95% CI 1.20–1.90, P < 0.001). The cumulative probability of DR was also higher in the endometrial cancer group than in the control group (P < 0.001). The relationship between endometrial cancer and DR was significantly higher in patients aged over 70 years (P = 0.008). In addition, a higher incidence of DR was found during the first 5 years after the endometrial cancer diagnosis (P < 0.001). Conclusions: The endometrial cancer correlates to a higher incidence of subsequent DR, especially within first 5 years of endometrial cancer diagnosis.