# Breast arterial calcifications on mammography and risk of stroke: a systematic review and meta-analysis

## TL;DR

Breast arterial calcifications seen on mammograms are linked to a higher stroke risk in women, even after adjusting for known risk factors.

## Contribution

This study is the first to systematically show that breast arterial calcifications are an independent predictor of stroke risk in women.

## Key findings

- Women with breast arterial calcifications had more than double the stroke risk compared to those without.
- BAC was associated with older age, hypertension, diabetes, and postmenopausal status.
- Smokers were less likely to have breast arterial calcifications.

## Abstract

Breast arterial calcifications (BAC) are commonly observed as an incidental finding on screening mammography and have been linked to cardiovascular disease. Whether BAC is independently associated with stroke risk remains uncertain.

We conducted a systematic review and meta-analysis in accordance with PRISMA 2020 guidelines. PubMed, Embase, and Scopus were searched from inception to May 2024 for cohort studies evaluating the association between BAC and stroke. Eligible studies included women undergoing mammography with documented BAC status and subsequent stroke outcomes. Data on patient characteristics and vascular risk factors were extracted. Study quality was appraised using the Joanna Briggs Institute (JBI) Critical Appraisal Checklist. Random-effects meta-analyses with restricted maximum likelihood (REML) estimation were performed to pool risk ratios (RRs) and mean differences (MDs). Heterogeneity was assessed with the I2 statistic, and publication bias with Egger’s test.

Ten cohort studies including 52,413 women were analyzed. The presence of BAC was associated with more than a twofold increased risk of stroke (RR 2.09, 95% CI 1.58–2.75; I2 = 64.4%). This association persisted after adjustment for age, diabetes, hyperlipidemia, and menopausal status. Compared with BAC-negative women, those with BAC were significantly older (MD 7.07 years, 95% CI 5.44–8.70) and more frequently hypertensive (RR 1.48, 95% CI 1.23–1.78), diabetic (RR 1.67, 95% CI 1.38–2.02), hyperlipidemic (RR 1.27, 95% CI 1.07–1.51), and postmenopausal (RR 1.26, 95% CI 1.00–1.59). Interestingly, BAC was less common among smokers (RR 0.62, 95% CI 0.45–0.86). Egger’s test showed no evidence of publication bias (p = 0.143).

BAC detected on screening mammography is independently associated with an increased risk of stroke, even after accounting for traditional risk factors. These findings support BAC as a promising, underutilized imaging biomarker of cerebrovascular risk in women and highlight the need for standardized reporting and prospective validation.