2296-P: Comparing Incidence of Diabetes Complications and Mortality between Breast and Colon Cancers: A TriNetX Study

Introduction and Objective: Patients with type 2 diabetes mellitus (T2DM) are at an increased risk of complications after a cancer diagnosis. Whether cancer type differentially influences the development and timing of diabetic microvascular complications is not well defined. The objective of this study was to determine whether non-metastatic breast cancer, compared to non-metastatic colon cancer, is associated with differences in mortality and microvascular complication incidence and timing among adults with T2DM and no baseline complications. Methods: We conducted a retrospective, propensity score-matched cohort study using TriNetX data. Adult females ≥18 years with T2DM and either non-metastatic breast cancer or non-metastatic colon cancer were included. Cohorts were 1:1 propensity score matched on demographics, medications, HbA1c, eGFR, and comorbidities. Diabetic nephropathy, blindness, and all-cause mortality were assessed at 2-, 5-, and 10-year follow-up windows using risk ratio (RR) and Cox proportional hazard models (HR). Results: The matched cohorts yielded 4,672 patients per cohort. Compared with colon cancer, breast cancer was associated with lower mortality at 2 years (HR=0.687, 95% CI 0.601-0.787, p<0.0001) persisting through all follow-up intervals. Breast cancer was associated with lower diabetic nephropathy hazard observed at 2 years (HR=0.761, 95% CI 0.597-0.970, p=0.027) and 10 years (HR=0.870, 95% CI 0.781-0.969, p=0.012). In contrast, higher incidence of blindness was observed at 5 years in breast cancer (RR=1.425, 95% CI 1.006-2.019, p=0.045) and 10 years (RR=1.383, 95% CI 1.076-1.778, p=0.011). Conclusion: In adults with T2DM, non-metastatic breast cancer was associated with lower mortality and delayed diabetic nephropathy but higher long-term blindness risk compared to non-metastatic colon cancer. These findings highlight critical windows for future investigation on risk-stratified survivorship care. Disclosure H. Chan: None. M. Dao: None. S.Y. Zhao: None. C. Xie: None. U. Phatak: None. C.J. Garza: None. W. Lee: None.