Abstract
Our biological and experimental findings on double esophageal carcinomas were reported. First, endoscopic screening and Lugol's staining of the esophagus was performed for head and neck cancer patients after treatment of primary lesions. Unstained lesions were found in 17 cases (29%), of which 7 cases (41%) revealed a positive p53 of biopsy samples in immunohistochemical staining. Moreover, 10 (24%) of the 41 normal stained cases revealed a positive p53 in samples biopsied from the middle esophagus. On the other hand, the microsatellite instability (MSI) of dysplastic lesions coexisting with esophageal carcinomas was investigated. Twenty-one (78%) of 24 dysplastic lesions of mutator phenotype esophageal carcinoma revealed a positive MSI, whereas only 5 (29%) of 17 dysplastic lesions of non-mutator phenotype esophageal carcinoma did so. These facts suggest that certain biological markers might predict secondary carcinomas in the esophagus and head and neck. Second, an epidemiologic study showed a high incidence of esophageal carcinoma after gastrectomy. The esophagus after gastrectomy was exposed to a more alkaline circumstance due to the reflux of duodenal juice, especially pancreatic juice, to the esophagus, which these seemed to cause the carcinogenesis in our patients. Therefore, preventive procedures against reflux esophagitis after gastrectomy should contribute to not only QOL but also to the prevention of secondary esophageal carcinoma.
