Abstract 4723: Prognostic significance of EGFR expression in localized gastric cancer

Abstract

Abstract Background: The role of epidermal growth factor receptor (EGFR) expression as predictive or prognostic biomarker in gastric cancer is still in controversy. The aim of this study is to find prognostic role of tumor EGFR expression in gastric cancer patients after curative resection. Methods: From January 2000 to September 2003, gastric cancer patients who received curative gastrectomy were included in this study. We retrospectively collected clinical characteristics and survival data of the patients, and analyzed EGFR expression on tissue microarrays from formalin-fixed paraffin-embedded specimens of primary tumor tissues by immunochemical staining (IHC). EGFR expression was scored to 0, 1+, 2+ or 3+ based on intensity of reactivity. Results: Of total 937 patients, 295 (31.5%) patients, 101 (10.8%) patients and 36 (3.8%) patients showed EGFR 1+, 2+, and 3+ expression by IHC, respectively. EGFR overexpression (2+/3+) is more frequently found in intestinal type than diffuse or mixed type (24.2% vs. 5.1%, P<0.001). In stage III disease according to AJCC 7th edition, unlike other stages, the patients with EGFR overexpression (2+/3+) had longer disease free survival (hazard ratio [HR], 0.639; 95% confidence interval [CI], 0.434-0.938; P=0.022) and longer overall survival (HR, 0.630; 95% CI, 0.445-0.890, P=0.009) than other patients in univariate analysis. Additionally, in 279 patients who had stage III gastric cancer with diffuse type histology and received 5-fluorouracil (5-FU) based adjuvant chemotherapy, EGFR overexpression was favorable prognostic marker for overall survival (HR, 0.365; 95% CI, 0.161-0.827; P=0.016) in multivariate analysis, while old age and lymphovascular invasion were poor prognostic factors. Conclusion: EGFR overexpression was potentially favorable prognostic biomarker for stage III gastric cancer, especially in the patients who received 5-FU based adjuvant chemotherapy. Citation Format: Ji Soo Park, Hyo Song Kim, Yoon Sung Bae, Sung Hoon Noh, Hyunki Kim. Prognostic significance of EGFR expression in localized gastric cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4723. doi:10.1158/1538-7445.AM2014-4723