Impact of insulin-like growth factor-1 receptor (IGF-1R), epidermal growth factor receptor (EGFR), and HER2 expressions on outcomes of patients with gastric cancer

4539 Background: Insulin-like growth factor-1 receptor (IGF-1R), epidermal growth factor receptor (EGFR), and HER2 expressions have been reported to correlate with clinical outcomes in several solid tumors. However, the clinical significance of these biomarkers in gastric cancer (GC) remains unclear. Detailed exploratory evaluations are required to better understand their clinical implications. Methods: The study group comprised 87 patients who underwent gastrectomy at National Cancer Center Hospital and subsequently received chemotherapy for recurrent or residual tumor. Using immunohistochemical techniques, we analyzed the expressions of IGF-1R, EGFR, and HER2 in surgically removed tumor specimens to determine the prognostic significance of these biomarkers. Results: IGF-1R expression (defined as >10% membranous staining) was found in 67 tumors (77%), EGFR in 55 tumors (63%), and HER2 in 16 tumors (18%). IGF-1R expression correlated with EGFR expression (P=0.019) as well as with HER2 expression (P=0.001). A univariate analysis revealed that IGF-1R expression correlated with shorter survival (P=0.030). A multivariate analysis of potential prognostic factors showed that IGF-1R expression, worse performance status and pathological stage, and diffuse type tumor were independent predictors of poor outcomes ( Table ). Conclusions: IGF-1R expression in surgical GC specimens may be a predictor of poor outcomes in postoperative patients with GC. Our data suggest that anti-IGF-1R strategies may prove valuable in such patients. [Table: see text] No significant financial relationships to disclose.