Analysis of genomic instability in esophageal squamous cell carcinoma (ESCC)

To characterize genomic instability in esophageal squamous cell carcinoma, we examined loss of heterozygosity, copy number loss, and copy number gain in ESCC patients from a high-risk region of China. Affymetrix SNP arrays were performed according to the manufacturer's directions on DNA extracted from microdissected esophageal squamous cell carcinoma samples or peripheral blood samples. Tumor DNA samples were normalized individually to the set of 102 peripheral blood samples. Copy number variations and loss of heterozygosity were determined by a paired analysis of tumor and blood DNA from the same individual.