Microsatellite instability in squamous cell carcinomas and dysplasias of the esophagus

Microsatellite instability (MSI) caused by the defective functions of misma tch repair genes plays an important role in the carcinogenesis of gastroint estinal tumors. However, little is known about the role of MSI in esophagea l carcinogenesis. In the present study, we conducted microsatellite assays on 41 esophageal carcinomas and also on 44 dysplasias of the esophagus with 7 separate microsatellite loci. MSI was detected in 17 cases (42%) among 4 1 esophageal carcinomas. MSI,CI negative cases revealed greater lymph node metastasis, metastasis at a mole advanced stage, a higher I recurrence leve l and a poorer prognosis (statistically not significant). In the analysis o f dysplasias, MSI was detected in 26 lesions (59%) among 44 lesions. Intere stingly, NISI was detected in 21 lesions (78%) from the mutator phenotype d ysplasias, but detected in only 5 lesions (29%) from the non-mutator phenot ype cases. Although the significance of MSI in esophageal carcinoma was not clear, these results indicate that MSI occurs in the early stage of esopha geal carcinogenesis.