Detection of epidermal growth factor receptor in the serum of gastric carcinoma patients

BACKGROUND. Epidermal growth factor receptor (EGFR) is overexpressed in various malignancies including carcinoma of the breast, lung, esophagus, cervix, and stomach. In patients with gastric carcinoma, its overexpression may be associated with advanced stage and poor prognosis. METHODS. The levels of EGFR extracellular domain were determined in serum from 40 gastric carcinoma patients using enzyme-linked immunosorbent assay. Serum EGFR levels were measured in 5 Stage I, 2 Stage II, 6 Stage III, and 27 Stage IV patients, and 29 healthy controls. RESULTS. The mean serum level for EGFR in the gastric carcinoma patients was significantly elevated compared with that of healthy controls (681 ± 226 fmol/mL vs. 440 ± 46 fmol/mL; P < 0.0001). Thirty-one patients with gastric carcinoma (77.5%) showed elevated EGFR levels above a cutoff value of 532 fmol/mL (defined as 2 standard deviations above the mean of the controls). No significant association was noted between positivity of EGFR and gender, age, stage, and tumor differentiation. CONCLUSIONS. The authors believe that serum EGFR could be useful as a tumor marker of gastric carcinoma for diagnosis, prognosis, follow-up after surgery, and monitoring patient response to chemotherapy.