Heinrich et al (2003) reported cerebral metastases in 43% of 51 patients with HER-2-overexpressing breast cancer receiving trastuzumab. Brufsky et al (2003), in a phase II study of docetaxel, carboplatin, and trastuzumab in 38 patients, observed that out of those patients progressing on therapy 50% developed CNS disease. This evidence concerns the gene ERBB2 and breast carcinoma.