Several dozen genetic variants have been linked to a greater risk of developing prostate cancer, but this is the first to be associated with aggressiveness of the disease, Xu said.
"The entire field has a long way to go, but this is an important first step," he said.
One indication of the distance to be traveled is the finding that the variant is located in a part of the genome where no gene has been found. This is not an uncommon finding, Xu explained, since many of the risk-associated variants are not in genes. "Our understanding of how the genome works is very limited," he said.
Still, much can be accomplished with what is known, with appropriate changes in strategy, Xu noted. Until now, the focus in prostate cancer has been on finding variants that affect the risk of developing the malignancy. "If you use that approach, it is difficult to distinguish aggressive from non-aggressive cancers," he said. "If you compare two groups of patients, one with indolent disease, one not, you are more likely to find those variants."
A second study comparing the genomes of 1,000 men with aggressive prostate cancer and an equal number with the indolent form of the disease is under way, with results expected to be published later this year, Xu added. The hope is to find a series of variants that might eventually be used by physicians in a screening test to help determine when more than watchful waiting is needed for prostate cancer, he said.
"Our work is too early to say whether it will have a clinical impact," said William B. Isaacs, a professor of urology and oncology at Johns Hopkins Medical Institutions, and a member of the research team. "It wont change the approach to identifying men with the aggressive form of prostate cancer. But this demonstrates that such markers do exist, and by studying them we may be able to understand the biological pathways that contribute to making prostate cancer mor
All rights reserved