The Nation's Investment in Cancer Research

Following Important Leads

Genome-Wide Association Studies

One of NCI’s promising avenues of research, genome-wide association studies (GWAS), has begun to reveal some of the key genetic factors that affect risk for many cancers. Genome-wide association studies involve two groups: those with a given cancer and a group of equal size that does not have the disease. Through genetic characterization, followed by finer and finer mapping and analysis, scientists are able to identify common genetic aspects for the cancers being studied. These new findings, in breast, prostate, colon, and other cancers, have raised hopes that genetic profiles based on germline genetic variation could identify individuals at high risk for cancer and also identify who might benefit from a variety of interventions.

Across all diseases, in just the last three years, genome-wide association studies have identified more than 150 common markers associated with over 40 common diseases. Yet, as Stephen J. Chanock, M.D., chief of NCI’s Laboratory of Translational Genomics in the Division of Cancer Epidemiology and Genetics, often reminds colleagues, we are “at the beginning of the beginning.” Genome-wide association studies will be the basis for future laboratory studies, with the goals of regulating gene expression and understanding cell biology, in order to fully comprehend alterations in cellular function and to design novel gene and drug therapies that will be effective at the earliest possible points in cancer’s development.

Importantly, the vast expansion of genome-wide association studies in U.S. and international laboratories has benefitted from a tremendous boost in technology. The Human Genome Project cost approximately $2.7 billion to complete. According to Science, by 2006, a draft genome sequence of the rhesus monkey cost $22 million. Today the race is on for the $1,000 genome sequence that can be completed in virtually real time. So, in addition to the boon in technology, the costs saved by advancing technology may be as tremendous.