Prognostic Value of Signal Transducers and Activators of Transcription 3 in Breast Cancer

Introduction: Constitutively activated signal transducers and activators of transcription (STAT) proteins are found in various types of tumors. However, there is still very limited information about the role of STATs in breast cancer. The power of tissue microarray technique is the capability of doing a series of analyses of thousands specimens in a parallel fashion with minimal damage to the origin blocks. This study was designed with the application of tissue microarray to analyze the STAT3 status in breast cancer. Materials and Methods: Archival tissue specimens from 102 patients with primary invasive breast cancer were selected, and STAT3 expression was analyzed by immunohistochemical staining with tissue microarray. The data of primary tumor staging, age, estrogen receptor status, lymph node status, histologic grading, and tumor-node-metastasis staging were also collected. Results: By multivariate analysis, the STAT3 expression turned out to be significantly related to the overall 5-year survival rate ( P = 0.024). Conclusion: Immunohistochemical staining with tissue microarray was convenient and feasible for the analysis of STAT3 expression status in breast cancer. Our preliminary results are promising and deserve further evaluation. (Cancer Epidemiol Biomarkers Prev 2008;17(9):2286–90)