Cancer Genetic Markers of Susceptibility (CGEMS)

CGEMS is a three-year, $14 million-dollar initiative to conduct whole-genome association studies to identify genes that confer susceptibility to prostate and breast cancer. Coordinated through the NCI’s Division of Cancer Epidemiology and Genetics, the Core Genotyping Facility, and the OCG, the project capitalizes on new knowledge of single nucleotide polymorphisms (SNPs) in human genetic variation and technical advances in ultra-high-throughput genotyping.

SNPs are the most common form of human genomic variation; most of the approximately ten million SNPs with a minor allele frequency greater than 5 percent occur in genomic segments in which they correlate highly with each other (i.e., they are in linkage disequilibrium). Data from the International HapMap Project Phase 2 indicate that a minimum of 550,000 carefully-chosen SNPs will be required to conduct a comprehensive whole-genome SNP scan.

CGEMS is designed to conduct whole-genome scans in nested case-control studies of prostate and breast cancer from ongoing population-based cohort studies. Each whole-genome scan will analyze approximately 1,200 cases and 1,200 controls. Because the large number of SNP comparisons in a whole-genome scan will likely generate many false positive signals, follow-up sequential replication studies will be used to validate true positive associations. Using this procedure, CGEMS will assess the 15,000-20,000 top candidate SNPs from the whole-genome scans in follow-up case-control studies. Rapid public access to data generated by CGEMS will be facilitated by caBIG™.

The data generated by CGEMS prostate cancer study is available through the CGEMS data access portal.

To learn more about the Cancer Genetic Markers of Susceptibility Program, visit http://cgems.cancer.gov.