Tylosis esophageal cancer locus on chromosome 17q25.1 is commonly deleted in sporadic human esophageal cancer

Background & Aims: Tumor-suppressor genes found in inherited cancer predisposition syndromes are also responsible for sporadic cancers of the same type. Recently, the tylosis oesophageal cancer (TOC) gene locus has been mapped to 17q25 by linkage analyses of pedigrees with focal nonepidermolytic palmoplantar keratoderma associated with a high risk of esophageal cancer development. The aim of this study was to clarify whether the TOC locus is affected in sporadic esophageal cancers. Methods: We investigated loss of heterozygosity (LOH) on 17q in 58 sporadic esophageal squamous cell carcinomas (ESCs) using 20 microsatellite markers focusing on the TOC locus. Results: LOH on 17q was observed in 37 of 52 (71%) informative cases at one or more loci, 89% (33/37) of which included the TOC locus. The smallest common deleted region was at D17S1839 within the TOC locus. Conclusions: The constructed deletion map revealed that the TOC locus is commonly deleted in sporadic ESCs, suggesting that a tumor-suppressor gene responsible for ESC is contained within this locus. GASTROENTEROLOGY 1998;114:1206-1210