The association between breast arterial calcification and atherosclerotic cardiovascular disease in an Australian population-based breast cancer case–control study

Purpose Atherosclerotic cardiovascular disease (ASCVD) is a major cause of morbidity and mortality. Breast arterial calcification (BAC) on mammograms is not associated with breast cancer risk. However, there is increasing evidence supporting its association with cardiovascular disease (CVD). This study examines the association between BAC and ASCVD and their risk factors within an Australian population-based breast cancer study. Materials and methods Data from the controls who participated in the breast cancer environment and employment study (BCEES) were linked with the Western Australian Department of Health Hospital Morbidity database and Mortality Registry to obtain ASCVD outcomes and related risk factor data. Mammograms from participants with no prior history of ASCVD were assessed for BAC by a radiologist. Cox proportional hazards regression was used to examine the association between BAC and later occurrence of an ASCVD event. Logistic regression was used to investigate the factors associated with BAC. Results A total of 1020 women with a mean age of 60 (sd = 7.0 years) were included and BAC found in 184 (18.0%). Eighty (7.8%) of the 1020 participants developed ASCVD, with an average time to event of 6.2 years (sd = 4.6) from baseline. In univariate analysis, participants with BAC were more likely to have an ASCVD event (HR = 1.96 95% CI 1.29–2.99). However, after adjusting for other risk factors, this association attenuated (HR = 1.37 95% CI 0.88–2.14). Increasing age (OR = 1.15, 95% CI 1.12–1.19) and parity ( p LRT < 0.001) were associated with BAC. Conclusion BAC is associated with increased ASCVD risk, but this is not independent of cardiovascular risk factors.