High incidence of EGF receptor hyperproduction in esophageal squamous-cell carcinomas

EGF receptor levels were investigated in esophageal squamous-cell carcinoma tissues from 31 patients. Twenty-two (71%) of these cancer tissues exhibited significantly higher 125I-EGF binding activity than normal mucosa in the adjacent non-cancerous tissues. These EGF receptor levels were then compared on the basis of pathological findings including lymph-node metastasis, depth of invasion, differentiation type, vascular invasion, infiltration and location of the lesion. Unlike previous reports on breast and bladder cancers, our study showed no obvious correlation between these pathological characteristics and the EGF receptor levels in esophageal carcinomas. Immunohistochemical staining with the anti-EGF receptor monoclonal antibody detected EGF receptors in squamous cells of the cancer tissues as well as in the basal cells of nearby normal epithelium. Since the basal cells have proliferative potential in the esophagus, the increase in EGF receptor levels in these cells may possibly be associated with the development of human esophageal squamous-cell cancer.