Incident diabetes among older Asian, Native Hawaiian, and Pacific Islander women with breast cancer.

Background: The risk of diabetes among Asian, Native Hawaiian, and Pacific Islander (ANHPI) women after breast cancer is unclear. This study estimated the risk of incident type II diabetes in older ANHPI and older non-Hispanic White (NHW) women with breast cancer from the US National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) Medicare linked claims.

Methods: A matched cohort of 7122 older ANHPI and 21 365 older NHW women with breast cancer were identified from SEER-Medicare between 2000 and 2017. To assess the risk of incident type II diabetes after breast cancer, hazard ratios (HRs) and 95% confidence intervals (95% CI) were estimated using the Cox proportional-hazards regression model.

Results: During the mean 8 years of follow-up, 9.3% of older women with breast cancer developed incident type II diabetes. In comparison with older NHW women, older ANHPI women without a known history of diabetes had an elevated risk of diabetes after breast cancer, with strong associations observed for Pacific Islander (HR = 3.09, 95% CI = 1.43 to 6.67), Vietnamese (HR = 2.12, 95% CI = 1.33 to 2.36), and Filipino (HR = 2.02, 95% CI = 1.57 to 2.59) women with breast cancer, adjusting for potential confounders. Among ANHPI women with breast cancer, more baseline comorbidities and obesity were risk factors for developing incident type II diabetes.

Conclusion: ANHPI women diagnosed with breast cancer had an elevated risk of type II diabetes compared with older NHW women with breast cancer. Routine monitoring and management of diabetes are warranted in older ANHPI women with breast cancer.