An evaluation of focal adhesion kinase in breast cancer by tissue microarrays

Background: Many studies have shown that focal adhesion kinase (FAK) is a positive regulator of tumor progression and invasion. However, there is still very limited information about the role of FAK in breast cancer. Tissue microarrays (TMA) can analyze thousands of tissue samples in a parallel fashion with minimal damage to the origin block. This study was designed with the application of TMA to analyze the FAK status in breast cancer. Patients and Methods: Archival tissue specimens from 98 patients with primary invasive breast cancer were selected and FAK expression was analyzed by immunohistochemical staining with TMA. The data of primary tumor staging, age, estrogen receptor status, lymph node status, histological grading and TNM staging were also collected. Results: There were four patients (4.0%) with grade 1 expression in FAK, 41 patients (41.8%) with grade 2 expression in FAK and 53 patients (54.2%) with grade 3 expression in FAK. There was no significant relationship between FAK expression and age, estrogen receptor status, histological grading, primary tumor staging, lymph node status and TNM stage. By multivariate analysis, the TNM stage was found to be significantly related to the overall five-year survival rate (p<0.00001). Conclusion: Immunohistochemical staining with TMA is a convenient and feasible method. Unfortunately, our preliminary results fail to show meaningful prognostic value of FAK in breast cancer. A larger prospective study is warranted for further evaluation.