Functional pathway characterized by gene expression analysis of supraclavicular lymph node metastasis-positive breast cancer

The outcome of breast cancer patients with supraclavicular lymph node metastasis is generally poor, but some patients do survive for a long time. Consequently, the ability to predict the outcome is important in terms of choosing the appropriate therapy for breast cancer patients with supraclavicular lymph node metastasis. In this study, we attempted to identify functional pathways that determine the outcome of breast cancer patients with supraclavicular lymph node metastasis by profiling cDNA microarrays. Thirty-one breast cancer patients with supraclavicular lymph node metastasis without distant metastasis comprised the study cohort; these were divided into three groups based on prognosis - poor, intermediate, and good. Two functional pathways, the Wnt signaling pathway and the mitochondrial apoptosis pathway, were constructed using six genes (DVL1, VDAC2, BIRC5, Stathmin1, PARP1, and RAD21) that were differently expressed between the good and poor outcome groups. Our results indicate that these two functional pathways may play an important role in determining the outcome of breast cancer patients with supraclavicular lymph node metastasis. We also determined that immunohistostaining for the Stathmin1 gene product is a potential tool for predicting the outcome of breast cancer patients with supraclavicular lymph node metastasis.