NEW YORK (Reuters) -- For the first time, researchers have identified a gene segment that may increase susceptibility to prostate cancer. The finding may eventually lead to identification of a specific gene and possibly a new way to test for the cancer, which kills about 40,000 men every year in the U.S.
"The study provides the first strong evidence that specific genes for prostate cancer do exist," stated senior investigator Dr. William Isaacs in a release from the National Institutes of Health (NIH). "And it's a major step toward findings those genes," said Isaacs, an associate professor of urology and oncology at Johns Hopkins University in Baltimore.
The gene region, designated the hereditary prostate cancer 1-gene, or HPC-1, is located on chromosome 1, the first of 43 chromosome pairs found in every human cell. The proposed gene site was identified after testing individuals from more than 90 prostate-cancer prone families (three or more affected members) from the United States and Sweden, according to the report in this week's issue of Science. Researchers from the National Center for Human Genome Research (NCHGR) at the NIH and the Umea University in Sweden collaborated on the project.
While 1 in 5 men will develop prostate cancer at some point during their lifetime, about 1 out of 500 men carry an alteration in HPC-1, the researchers estimated. Nine percent of all prostate cancers and 40% of cases that occur in younger men are thought to be due to an inherited susceptibility to the cancer. The newly discovered gene region may be responsible for about a third of these hereditary cases.
And HPC-1 may help explain the increased prostate cancer risk in certain ethnic groups, including African-American men, who have the highest prostate cancer risk in the world.
"We know this gene seems to contribute to prostate cancer risk in a number of ethnic backgrounds," stated study co-author Dr. Jeffrey Trent, in the NIH release. "There's linkage in Swedish families as well as American families, including African-American families," said Trent, a scientific director of intramural research at the NCHGR.
Every year 317,000 U.S. men are diagnosed with cancer of the prostate, the small walnut-shaped gland that surrounds the urethra. Unlike other cancers, prostate cancer can be slow-growing and may not become life-threatening for many years.
SOURCE: Science (1996;274:1371-1374)
