Hypoxia gene expression signature in predicting outcome in breast cancer patients

9503 Background: Gene expression profiling (GEP) has been used to identify specific subgroups of breast carcinomas (BC) that differ with respect to clinical and pathological features, including outcome. We have previously identified an expression pattern of 70 genes, associated with a high risk of developing distant metastases. Recently, we have identified a gene expression profile associated with hypoxia by exposing epithelial cells to hypoxic conditions in vitro. We hypothesized that genes induced by hypoxia may distinguish different (biological) classes of breast cancer and have therefore studied the hypoxia gene expression signature in a series of breast carcinomas. Methods: In a series of 295 patients with stage I and II breast cancer, we have previously obtained the expression profile of 25000 genes using microarray analysis. Based on the hypoxia gene expression profile, we have identified a subgroup of BC showing a “hypoxia-like profile” and a subgroup that did not; and we have compared distant met...