By Alicia Chang
LOS ANGELES — Researchers analyzing the genetic makeup of ovarian cancer tumors have found a gene mutation that is surprisingly frequent, suggesting it plays a key role in driving the cancer.
The finding, appearing in Thursday’s issue of the journal Nature, may eventually lead to tests for earlier diagnosis of the disease and to better treatment. Ovarian cancer kills nearly 14,000 women in the United States each year. It’s usually not spotted until at an advanced stage.
The gene sequencing was carried out by The Cancer Genome Atlas, a federally funded network of medical centers that analyzed 316 ovarian tumors.
Scientists found that 96 percent of the tumors had mutated TP53 genes. The mutations were not present in normal tissue from the patients, showing they arose within the tumors. Normally, the gene directs the cell how to make a protein that acts as a tumor suppressor, keeping cells from growing and dividing uncontrollably.
Alterations in nine other genes also played a role in ovarian cancer, though to a much lesser extent, the researchers reported. Among them were the BRCA1 and BRCA2 genes, which increase the risk of breast and ovarian cancer.
“In other cancers, there are usually several genes that are involved” on almost equal footing, said one of the study authors, Dr. David Wheeler of Baylor College of Medicine. “This is an unusual pattern.”
The new work “is producing impressive insights into the biology” of ovarian cancer, Dr. Francis Collins, who heads the National Institutes of Health, said in a statement.
Among cancers, ovarian is the fifth leading cause of death among women. A regular pelvic exam is considered the best way to detect ovarian cancer early.
The Cancer Genome Atlas was launched in 2006 to unravel the genetic underpinning of cancer. The group mapped the genome of the most common form of brain cancer in 2008 and plans to do the same for 20 other types of cancers.