||Study results, reported in Cancer, showed that the large majority of BRCA1 mutation carriers (73%) had triple-negative breast cancer, whereas the large majority of BRCA2 mutation carriers (72%) had hormone receptor–positive breast cancer.|
CNS involvement was seen in 53% of the BRCA1 mutation carriers and 50% of the BRCA2 mutation carriers, compared with 25% of the noncarriers
(P less than .001). “If anything, given that our institutional practice is not to obtain routine brain imaging in the absence of symptoms or a clinical trial requirement, our results may even underestimate the true frequency of CNS involvement in BRCA1/BRCA2 mutation carriers,”
Dr. Lin and colleagues note.
In multivariate analysis controlling for tumor subtype, BRCA2 mutation was independently associated with CNS involvement (odds ratio, 3.33; P = .006). In contrast, BRCA1 mutation was not (OR, 2.11; P = .18).
Similarly, BRCA2 mutation independently predicted breast cancer–related death (hazard ratio, 1.82; P = .01), but BRCA1 mutation did not (HR, 1.21; P = .48). Additional predictors included triple-negative subtype, compared with other subtypes (HR, 4.22; P less than .001) and, relative to locoregional or contralateral disease as first recurrence, CNS involvement (HR, 10.91; P less than .001) and non-CNS distant site involvement (HR, 3.90; P less than .001).