Risk of Cardiometabolic Risk Factors in Women With and Without a History of Breast Cancer: The Pathways Heart Study

Breast cancer survivors had higher risk of diabetes up to 10 years after diagnosis compared with healthy women. PURPOSE The incidence of cardiometabolic risk factors in breast cancer (BC) survivors has not been well described. Thus, we compared risk of hypertension, diabetes, and dyslipidemia in women with and without BC. METHODS Women with invasive BC diagnosed from 2005 to 2013 at Kaiser Permanente Northern California (KPNC) were identified and matched 1:5 to noncancer controls on birth year, race, and ethnicity. Cumulative incidence rates of hypertension, diabetes, and dyslipidemia were estimated with competing risk of overall death. Subdistribution hazard ratios (sHRs) were estimated by Fine and Gray regression, adjusted for cardiovascular disease-related risk factors, and stratified by treatment and body mass index (BMI). RESULTS A total of 14,942 BC cases and 74,702 matched controls were identified with mean age 61.2 years and 65% non-Hispanic White. Compared with controls, BC cases had higher cumulative incidence rates of hypertension (10.9% v 8.9%) and diabetes (2.1% v 1.7%) after 2 years, with higher diabetes incidence persisting after 10 years (9.3% v 8.8%). In multivariable models, cases had higher risk of diabetes (sHR, 1.16; 95% CI, 1.07 to 1.26) versus controls. Cases treated with chemotherapy (sHR, 1.23; 95% CI, 1.11 to 1.38), left-sided radiation (sHR, 1.29; 95% CI, 1.13 to 1.48), or endocrine therapy (sHR, 1.23; 95% CI, 1.12 to 1.34) continued to have higher diabetes risk. Hypertension risk was higher for cases receiving left-sided radiation (sHR, 1.11; 95% CI, 1.02 to 1.21) or endocrine therapy (sHR, 1.10; 95% CI, 1.03 to 1.16). Normal-weight (BMI < 24.9 kg/m(2)) cases had higher risks overall and within treatment subgroups versus controls. CONCLUSION BC survivors at KPNC experienced elevated risks of diabetes and hypertension compared with women without BC depending on treatments received and BMI. Future studies should examine strategies for cardiometabolic risk factor prevention in BC survivors.

Automated summary

Breast cancer survivors have a higher risk of developing diabetes compared to healthy women for up to 10 years after diagnosis. The risk is influenced by the type of treatment received, such as chemotherapy, left-sided radiation, and endocrine therapy, as well as the individual's body mass index (BMI). Strategies should be explored to prevent cardiometabolic risk factors in breast cancer survivors.