UICC World Cancer Congress 2006

Methods: Polymerase chain reaction was done in 60 samples using genomic DNA and six microsatellite markers. Loss of heterozygosity and microsatellite instability was done by single stranded conformation polymorphism (SSCP). Equal quantities of RNA obtained from 20 tumor and matched normal tissue biopsies were reverse transcribed, labeled with Cy3- and Cy5-dUTP and hybridized with human 10K cDNA chip. Differentially expressed genes were expressed as up regulated (ratio > 2.0) and down regulated (ratio < 0.5).

Results: A history of tobacco consumption and a family history of cancer were present in 85% and 26% patients respectively. The frequency of allelic alterations using different microsatellite markers was 63% (D17S1303), 53% (D11S1984 and D3S1766), 44% (D9S910), 30% (D13S796) and 18% (D13S894). Gene expression and hierarchical clustering across patients showed consistent molecular profile with 2 up regulated and 14 down regulated genes. Preliminary results indicate frequent chromosomal aberrations in esophageal cancer patients of Northeast India. cDNA microarray may be a useful tool to identify differentially expressed genes in these patients. In India, this is the first reported genetic profiling study that may serve as basis for development of markers for genetic susceptibility and screening for early detection of esophageal cancer in this high-incidence region.