Abstract: Aspects of the invention include methods for identifying patients with HER2+ cancers that are at a heightened risk for developing brain metastasis within three years of having been diagnosed with HER2+ cancer. Some embodiments are methods that include the steps of contacting at least a portion of the tumor tissue from patients with probes that interact with the products of a set of thirteen genes that are expressed in these patients at markedly higher levels than in similarly situated patients that are not a heightened risk for developing brain metastasis within this three year window. In some embodiments the tissue samples are assayed from the presence of RNA indicative of the expression of member of a set of 13 genes identified as being differentially expressed in patients with and without a heightened risk for developing brain metastasis.

Abstract: Disclosed is a method of treating a localized carcinoma central nervous system (CNS) metastasis of extra-CNS origin, the method comprising systemically administering an effective amount of a histone deacetylase (HDAC) inhibitor (HDI) to a subject in need of treatment for the localized carcinoma CNS metastasis of extra-CNS origin. The HDI can be any HDI capable of crossing the blood-brain barrier (BBB) such as vorinostat. The localized carcinoma CNS metastasis of extra-CNS origin can be a localized carcinoma brain metastasis. The localized carcinoma brain metastasis can originate in the breast. The CNS metastasis treated can be a micrometastasis, a brain tumor, or an intervening stage of brain cancer.