Genetic prognostic index influences patient outcome for node-positive breast cancer

Purpose. To establish a novel genetic prognostic index among node-positive breast cancer patients. Methods. Using a cDNA microarray, the gene expression profiles of 20 primary breast cancers that had metastasis to four or more axillary lymph nodes were examined. Ten patients survived disease-free for more than 5 years (5S), while ten patients died of breast cancer within 5 years of surgery (5D). Results. A set of genes characterizing each group was identified. Sixteen genes were underexpressed in 5D compared to 5S, and 15 genes were underexpressed in 5S in comparison to 5D. The prognostic index (PI) was established, which could predict the postoperative outcome with five genes that were commonly underexpressed in the 5D group; these genes encoded granulin (GRN), heat shock 90 kDa protein 1 beta (HSPCB), large tumor suppressor homolog 1 (LATS1), valosin-containing protein (VCP), and LIM-and-SH3 protein1 (LASP1). Conclusion. These five genes might play an important role in deciding the behavior of node-positive breast cancer. The PI system could thus predict the prognosis of node-positive breast cancer, and might therefore be able to provide valuable information for the prognosis of breast cancer patients.