Risk Factors of Cardiovascular Disease in Breast Cancer Patients

Introduction: Cardiovascular disease (CVD) events during cancer treatment can interfere with the delivery of curative therapy. In adult cancer survivors, CVD mortality is second only to cancer recurrence related mortality. We evaluated the demographic and clinical risk factors of CVD in breast cancer patients. Methods: A retrospective cohort study was conducted at Kaiser Permanente Southern California (KPSC) health system. We identified adult members (18+) diagnosed with primary breast cancer from 01/2000-12/2019 using the KPSC cancer registry. We only included patient who had at least one year of continuous health plan enrollment prior to their cancer diagnosis to determine risk factors status and to ensure they did not have any history of CVD (defined as cardiac arrest, cardiomyopathy, congestive heart failure, coronary atherosclerosis, heart valve disorders, myocardial infarction, ventricular fibrillation, dysrhythmias or stroke) prior to their cancer diagnosis. We evaluated the association of age at cancer diagnosis; race; ethnicity; obesity; cancer stage; and history of depression, drug abuse, renal failure, liver disease, lipid disorder, diabetes and hypertension using a proportional hazard model. All patients were followed from their cancer diagnosis to the earliest date of CVD (failure event) diagnosis or death or health plan disenrollment or end of study (12/2020). Results: In the cohort of 36,840 patients (Table 1), 11,993 (33%) had a CVD diagnosis during follow-up (average follow-up 5.3 years). The hazard rate of CVD increased significantly with age. Distant metastatic disease was associated with 7-fold higher CVD hazard as compared to in-situ cancer. Most other clinical factors significantly increased the hazard rate (Table 1). Conclusions: In breast cancer patients naïve to CVD disease prior to cancer diagnosis, the hazard rate of CVD post cancer diagnosis is significantly higher in older individuals and those with metastatic disease.