Mutation of breast cancer susceptibility genes increases cerebral microbleeds: A pilot study

Growing evidence suggests breast cancer susceptibility gene (BRCA) mutations may augment cerebrovascular risk factors. With this influence in mind, we aimed to identify if BRCA mutations increased the prevalence of cerebral small vessel disease (CSVD).

We performed a retrospective cross-sectional analysis of adults undergoing malignancy evaluation with confirmed BRCA mutations compared to BRCA wildtype individuals. A standard-of-care brain MRI was reviewed. Chi-squared or Fisher's, Wilcoxon rank-sum and the Student's t-test analyses were used when appropriate. Adjusted logistic regression models were fit to calculate odds ratio. Multicollinearity was tested by variance inflation factor calculation and for goodness-of-fit via the Hosmer-Lemeshow test.

Of 116 individuals, 44.8% (52/116) carried a BRCA mutation. Demographic and cerebrovascular risk factors did not differ. Cerebral microbleeds were more common in those with BRCA mutation: [32.7% (17/52) vs. 17.2% (11/64), p = 0.05] with an adjusted odds ratio of 2.8 (95%CI 1.08-6.89, p = 0.03). Other markers of CSVD were similar amongst the cohort.

We identified a nearly 3-fold increase in identified cerebral microbleed in those with BRCA mutations compared with BRCA wildtype individuals suggestive of an interaction between the BRCA gene and cerebral microbleed formation. Further studies are needed to confirm our findings and to understand clinical implications.