In September of this year, deCODE Genetics announced that a team of its scientists discovered four novel single-letter variations in the sequence of the human genome (SNPs) conferring increased risk of prostate cancer. (online edition of Nature Genetics, September 20, 2009)
Dr. Catalona and his research collaborators are an integral part of the United States team participating in the deCODE research.
This ongoing collaboration has now resulted in the discovery of 12 prostate cancer risk alleles.
QUEST reported in its Fall 2006 issue on A Most Exciting Discovery: A Gene That Appears to Pass on the Risk of Prostate Cancer. A group of scientists and doctors from around the world, including Dr. William J. Catalona, participated in that study with deCODE Genetics.
Then, QUEST reported in its Winter 2007 issue on the search for genetic hot spots in prostate cancer patients and told about the work of Brian Helfand, MD, PhD, whose research was based upon 799 patients (Catalona) who underwent radical prostatectomy at Northwestern Memorial Hospital.
“What we're looking for,” Helfand explained, “are places where a frequency of genetic changes match or correlate with a frequency of prostate cancer development.”
Looking for variations that might be connected to a specific disease is arduous and complicated. It can be compared to looking for, not just the needle in a haystack but, the head of the needle in a haystack.
Chromosome 8, containing one of the risk areas, for example, has about 146 million DNA base pairs. Only the development of new technology made the search possible.
deCODE continued its research and, this year, reported its discovery of four single-letter variations conferring increased risk of prostate cancer.
“Using our ability to put these SNPs in a population-wide context, it is now possible to identify those who are at more than 30% lifetime risk, independent of other standard risk factors such as age and family history...we can more effectively and accurately identify those men who would benefit most from intensive screening,” Kari Stefansson, MD, PhD, and CEO of deCODE, said.
Discoveries Yet to Come
What scientists don't understand yet is how or why these genetic variations affect prostate cancer risk, but, in addition to identification of risks, potential practical applications are apparent.
“They are already being used to develop some of the first clinical genetic tests for prostate cancer susceptibility and aggressiveness. And they may provide fundamental insights into the causes and development of prostate cancer, insights that could help us identify new molecular targets for treatment and prevention,” Dr. Catalona said.
“These findings,” he continued, “while only a beginning, hold promise for understanding what genetic changes cause prostate cancer and what interventions might prevent it from developing.”