Biologic and clinical significance of squamous epithelial dysplasia of the esophagus.

Squamous epithelial dysplasia is frequently encountered in the cancerous esophagus. However, its biological and clinical significance have not yet been fully elucidated. Investigations in squamous cell dysplasia of the esophagus have been performed to date in our department. We consider dysplasia to be the earliest malignancy of the esophagus based on such biologic features as the histopathologic findings, the proliferative activity, and the altered expression of cancer-associated genes. It is essential to detect and treat these early lesions endoscopically. Hopefully the findings of further studies of dysplasia can help to elucidate the mechanism of carcinogenesis in esophageal squamous cell carcinoma.