Global team finds new genetic variants that raise risk of prostate cancer
Date: Sep-18-2014In a large international study, scientists have identified 23 new genetic variants -
differences in sequences of DNA - that raise men's risk of developing prostate cancer above the
population average.
Researchers have identified 23 new genetic variants that significantly increase men's risk of developing prostate cancer.
Believed to be the largest meta-analysis of its kind, pooling data on over 87,000 men, the study
reveals previously unidentified mutations for prostate cancer among groups of European, African,
Latino and Japanese origin.
"Fifteen variants were identified among men of European ancestry, seven were identified in multi-ancestry
analyses and one was associated with early-onset prostate cancer," write the authors.
Some of the newly identified variants have already been linked to other cancers.
Together with 76 previously known, the new variants account for a third of the inherited
risk of developing prostate cancer in men of European descent. And, because the mutations are
inherited commonly among populations, they can surface in men with little or no family history of
prostate cancer.
All 23 of the variants - more specifically known as Single Nucleotide Polymorphisms, or SNPs,
(pronounced "snips") - that the study identifies are to be found in regions of DNA that do not
code for proteins. This suggests they are involved in regulating other genes rather than making
proteins.
The study authors, including two researchers from Johns Hopkins University School of Medicine in
Baltimore, MD, report their findings in the journal Nature Genetics.
Co-author Alan Partin, a professor of urology at Johns Hopkins, says:
"Inheriting any single one of these genetic variants has only a small effect on prostate cancer
risk. However, a subset of men will inherit many of these variants, putting them at substantially
increased risk for the disease, from 3-6 times the population average."
He suggests men with these risk levels should perhaps be encouraged to have screening
earlier.
Fellow co-author William Isaacs, a professor of oncology at Johns Hopkins, says using these
SNPs could serve as a "molecular family history" to enable better screening guidelines than
traditional family medical history backgrounds, which can be difficult to pin down.
Using the advantage of 'number power' to find the variants
By pooling data from smaller studies, the meta-analysis has the advantage of "number power," as
Prof. Isaacs explains:
"There is a power in numbers that helped us find new variants that were only hinted at in
smaller study populations, especially among minority men, and as we found the same variants across
several populations, the evidence became stronger that they were definitively linked to prostate
cancer."
All told, the samples included in the meta-analysis contained data from 43,303 prostate cancer
patients and 43,737 men without prostate cancer.
The analysis covered over 10 million areas of the genome looking for SNPs, where one sequence of
DNA is swapped over for another.
The researchers compared the scanned genome regions of prostate cancer patients with those of
men without prostate cancer to find the 23 new SNPs.
Meanwhile, Medical News Today also learned of a new genetic study led by researchers from the University of
Pittsburgh, PA, which may lead to a more accurate test for
aggressive prostate cancer and new ways to treat it.
Written by Catharine Paddock PhD
View all articles written by Catharine, or follow her on:
Courtesy: Medical News Today
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