Brain metastases (BM) in breast (BC) and lung cancer (LC) patients

Abstract

e12029 Background: Most BM arise from BC or LC. Few studies compare their attributes and distribution, though BC BM have been reported to more often involve the cerebellum. Methods: Brain scanning was for clinical evidence of BM. Contrast-enhanced computer-automated tomograms (CT) or magnetic resonance images (MRI) of brains of all BC and LC patients irradiated for BM between 1996 and 2008 were reviewed. BC epidermoid growth factor receptor2 (HER-2) expression was determined. Results: Data was from 63 BC and 59 LC patients; 58% of the BC and 55% of the LC patients had MRIs. MRIs showed more cerebellar BM (p = 0.047). Primary to BM diagnosis intervals were shorter for LC than for BC patients (p = 0.001), but LC BM were more edematous (0.019). BC patients had more cerebellar BM (p = 0.004) than LC patients, and more BM in the cerebellum only (p = 0.017). LC patient gender and small cell histology did not correlate with cerebellar BM. Both cerebrums and cerebellums of BC patients had more BM than those with LC (p = 0.020; 0.013). Cerebellar BMs were more frequent in brains with more cerebral BM (p = 0.0020). Amongst BC over-expressing HER-2 was a trend to more cerebellar BM (p = 0.072). Conclusions: LC BM, which elicit more edema, produce symptoms earlier than BC BM. There are larger numbers of BC BM, perhaps due to BC's longer disease course and responsiveness to therapy. BC causes more cerebellar mets than LC, often without cerebral BM. This may be due both to the larger number of BC BM, and a predilection for the cerebellum. Periodic brain MRI, more sensitive than CT to posterior fossa lesions, may be indicated in some BC patients, and early radiation may control multiple small BM. No significant financial relationships to disclose.