New genetic risk variants identified in multiethnic analysis of prostate cancer
Researchers have newly identified 23 common genetic variants -- one-letter changes in DNA known as single-nucleotide polymorphisms or SNPs -- that are associated with risk of prostate cancer. These results come from an analysis of more than 10 million SNPs in data pooled from studies that included over 43,000 men with prostate cancer and nearly 44,000 men without the disease. Study participants were from Australia, Ghana, Japan, the United Kingdom, and the United States and were of diverse ancestry. Fifteen of the newly identified variants were associated with increased risk of prostate cancer among men of European ancestry, seven were associated with increased risk in other populations, and one variant was associated with early-onset prostate cancer (prostate cancer in men under the age of 70). These 23 genetic variants, together with 76 prostate cancer risk variants identified in earlier studies, explain 33 percent of the familial risk of prostate cancer in populations of European ancestry. Additional studies are ongoing to explain risk in non-European populations. The study, co-led by Stephen J. Chanock, M.D., director of the NCI Division of Cancer Epidemiology and Genetics (DCEG), and colleagues, appeared in Nature Genetics September 14, 2014.
It is estimated that one in seven men in the U.S. will be diagnosed with prostate cancer in his lifetime. Studies have shown that both ancestry and family history are associated with prostate cancer risk, providing strong evidence for genetic predisposition to the disease. For example, men of African ancestry are known to be at the highest risk for developing prostate cancer; men of Asian ancestry are at lowest risk for this disease. By pooling data from numerous studies of men from diverse ethnic backgrounds, the investigators were better able to detect genetic risk factors shared among these populations. This collaborative effort highlights the importance of assembling studies with ancestrally diverse populations to identify markers of disease risk, according to Chanock.