Tissue status of epidermal growth factor and its receptor as an indicator of poor prognosis in patients with gastric cancer.

An immunohistological study of epidermal growth factor (EGF) and epidermal growth factor receptor (EGFR) was made with 157 specimens of stomach cancer. EGF stained positively in 70 specimens (45%), and EGFR in 53 specimens (34%). The cancers were classified into three groups; Group 1 with neither EGF nor EGFR staining positively (67 tumors); Group 2 with either EGF or EGFR staining positively (57 tumors); and Group 3 with both EGF and EGFR staining positively (33 tumors). The incidence rates of tumors of macroscopically infiltrative, poorly differentiated, deep invading and node-positive types were significantly higher for Group 3 than for Groups 1 and 2. The bromodeoxyuridine labeling indices (BrdU LIs) were significantly higher for Group 3 (median: 15.1%) than for Group 1 (median: 10.7%) or Group 2 (median: 11.4%). Patients with synchronous expression of EGF and EGFR (Group 3) had the poorest prognosis. From the results, it may be concluded that tumors with synchronous expression of EGF and EGFR have the highest malignant potentials and this phenomenon may cause autocrine secretion for self-replication.