Researchers find 23 genes linked to increased risk of prostate cancer
An international analysis has uncovered 23 previously unknown gene variants linked to elevated prostate cancer risk, findings that scientists say ultimately could lead to genetic screenings. Credit: iStock
An international analysis has uncovered 23 previously unknown gene variants linked to elevated prostate cancer risk, findings that scientists say ultimately could lead to genetic screenings.
For now, the indisputedly flawed but still useful PSA screening remains the only test doctors have for the condition. The new findings, however, add to the 77 previously known gene variants linked to prostate cancer and open a wider window on the genetic basis of a form of cancer that strikes about 223,000 men annually.
"The really wonderful thing about this [study] was that it included all the different ancestries," said Dr. Barbara Nemesure, a study co-author and professor of preventive medicine at Stony Brook University School of Medicine.
Nemesure said the study analyzed genomic data from people of European, African, Asian and Hispanic ancestry. Previous studies, she said, had looked at these groups individually. The new research allowed scientists to look at genetic information from about 40,000 men who had prostate cancer and 40,000 who did not have the disease.
"I am very excited about this research because it gives us a way forward. I don't think the PSA is going away but this may be a way to allow us to further interrogate the genome," she said of searching for still additional genetic variants linked to the disease.
The findings, Nemesure added, provide new opportunities for scientists to further investigate the potential genetic influences of prostate cancer shared among diverse populations.
Despite the discovery of 23 previously unknown gene variants linked to the malignancy, Nemesure said "there is still a lot we don't know about the role of genetics and prostate cancer."
One unsolved problem, she said, is being able to pinpoint genes related to indolent forms of the disease. These are cancers that progress at a glacial pace and do not predispose men to life-threatening forms of the disease. On the flip side -- and also as yet undiscovered -- are genes that signify the potential for aggressive, lethal forms of the cancer.
The American Cancer Society estimates that 30,000 men die annually of the disease.
The international team was led by Dr. Christopher Haiman, a professor of preventive medicine at the University of Southern California in Los Angeles. He described the investigation as a meta-analysis, a type of statistical study, which in this case unmasked new genomic data.
A meta-analysis, Haiman explained, is a tried-and-true method in which data are pooled from other investigations and re-analyzed.
Sometimes, as was the case in this research, new discoveries are made. "Yes, it was a statistical study but it was aimed at getting to a region of the genome. And the genome is where there is interesting biology," he said, referring to genes that put men at risk of the cancer.
"The goal of this research," Haiman said, "was to identify regions of the genome that contribute susceptibility . . . that could be used for understanding a man's future risk."
Breast cancer by comparison has had screenings for susceptibility since the mid-1990s. Tests can spot BRCA-1 and BRCA-2. Nemesure said a clinical study known as Barcode is underway in Britain to screen for genes related to prostate cancer.
Meanwhile, scientists at the University of Pittsburgh have found in a separate study that men already diagnosed with prostate cancer who carry a specific genetic mutation, identified by scientists there, are more likely to have a recurrence of the disease than men without that genetic flaw.
