Impacts of epidermal growth factor receptor, Her-2 and mTOR status on outcomes of patiets with gastric cancer

Background(Purpose): Expression of EGFR, Her-2 and mTOR have been linked to clinical outcomes in several solid tumors. However clinical significance of these biomarkers in gastric cancer remain unclear . This study was designed to detect the clinical implications of these three biomarkers in Turkish population.Methods: Paraffin -embedded tissue microarray blocks containing gastric cancer tissue obtained from 30 patients were constructed. Expression of mTOR, EGFR were detected by immunohistochemistry. Her-2 gene ampflication was detected by FISH. The correlation of these biomarkers to clinicopathologic features and survival of patients with gastric cancer was studied.Results: The overall rates of positive mTOR, EGFR and Her-2 status were 36.7%, 63.3% and 23.3% respectively. The EGFR expression was significantly correlated with better PFS(Progression Free Survival) and OS(Overall Survival)(p=0.039,p=0.01) There was no significant correlation with Her-2 status and survival. But 5 of these 7 Her-2 positive patients have already took trastuzumab treatment. Also we find that her-2 pozitive tumors significantly metastasized much more frequently to liver than her-2 negative tumors.(p= 0.043) In Contrast, her-2 positive tumors significantly metastasized less commonly to periton, over, omentum as seeding than her-2 negative tumors .(p=0.009). There was no association was noted between the expression of mTOR and survival time.Conclusion: EGFR is good prognostic marker in gastric cancer patients.