Attributes of brain metastases from breast and lung cancer.
Most brain metastases arise from breast and lung cancers. Few studies compare the brain regions they involve, their numbers and intrinsic attributes. Records of all patients referred to Radiation Oncology for treatment of symptomatic brain metastases were obtained. Computed tomography (n = 56) or magnetic resonance imaging (n = 72) brain scans were reviewed. Data from 68 breast and 62 lung cancer patients were compared. Brain metastases presented earlier in the course of the lung than of the breast cancer patients (p = 0.001). There were more metastases in the cerebral hemispheres of the breast than of the lung cancer patients (p = 0.014). More breast than lung cancer patients had cerebellar metastases (p = 0.001). The number of cerebral hemisphere metastases and presence of cerebellar metastases were positively correlated (p = 0.001). The prevalence of at least one metastasis surrounded with >2 cm of edema was greater for the lung than for the breast patients (p = 0.019). The primary tumor type, rather than the scanning method, correlated with differences between these variables. Brain metastases from lung occur earlier, are more edematous, but fewer in number than those from breast cancers. Cerebellar brain metastases are more frequent in breast cancer.