Abstract and Introduction
Abstract
Objective. We conducted a meta-analysis of the current literature to deduce the strength of association between breast arterial calcification (BAC) and coronary artery disease (CAD) and/or stroke.
Methods. PubMed, Google Scholar, ClinicalTrials.gov, and Ovid were searched for English-language literature up to August 2013 using the terms "breast arterial calcification," "breast vascular calcification," "coronary artery disease," "coronary heart disease," "cardiovascular disease," "abnormal coronary angiography," and "stroke." A hand search of the reference lists of key articles was performed to supplement the literature search. Our literature search revealed 75 articles for further abstract review. Limiting our search to articles that quantitatively assessed the correlation between BAC and stroke or angiographically proven CAD, we reviewed 35 full manuscripts. Of these articles, 14 were included in the final analysis.
Results. We analyzed 10 cross-sectional studies (n = 3,952) with CAD as the primary outcome (diagnosed by coronary angiography). The odds ratio (95% CI) for CAD in those with BAC versus those without BAC is 3.86 (3.25-4.59) (P < 0.0001). For stroke, six cross-sectional studies were analyzed (n = 18,888). The odds ratio (95% CI) for stroke in those with BAC versus those without BAC is 1.54 (1.25-1.90) (P < 0.0001).
Conclusions. These results suggest that BAC is significantly associated with both CAD and stroke. Although more prospective studies are warranted to clarify whether BAC is truly a predictor of the future development of CAD and stroke, the concept that BAC is a benign finding is waning.
Introduction
Breast arterial calcification (BAC) is one type of Monckeberg's sclerosis (medial calcific sclerosis) that is found in breast arteries. The characteristic pattern of BAC is a linear, parallel opacity that is often described as a "tramtrack" appearance on mammogram. Although BACs are a relatively common finding on mammograms with a reported overall prevalence of up to 29.4%, they are sporadically reported because they are not considered to be a warning sign of breast cancer.
Cardiovascular disease (CVD), including coronary artery disease (CAD) and stroke, remains a leading cause of morbidity and mortality among women aged 65 years or older. Preventative measures and increased screening methods are needed to decrease morbidity and mortality attributable to CVD.
It is well accepted that intimal arterial calcifications occur in the context of atherosclerosis. However, the clinical significance of medial arterial calcifications, identified in the middle or medial layer of breast arteries or arterioles, remains to be established. During the last decade, a number of investigators have assessed the association between BAC and cardiovascular risk factors and CVD events. Although several studies showed a statistically significant correlation between the presence of BAC and CVD, some studies found no association. These conflicting results highlight the need for a meta-analysis to increase sample size and thus the power to estimate the effect size of interest. A systematic review published recently concluded that the relationship between BAC and angiographic CAD remains undetermined; however, it was limited because it pooled and analyzed studies with different study designs (eg, merged cross-sectional studies with case-control studies). Compared with other diagnostic tools, coronary angiography offers more objective evidence of CAD. This meta-analysis further elucidates the association between BACs and angiographically proven CAD and stroke to determine whether more clinical research regarding the potential of BAC as an early predictor of CVD is warranted.