PHILADELPHIA (June 27, 2017) – Analyzing a panel of 25 genes, researchers found mutations in genes associated with increased risk of breast or ovarian cancer in approximately seven percent of women tested through a large commercial laboratory. In addition, the study helps to better quantify the magnitude of cancer risk associated with the genes tested. Depending on the gene, they found increased risk between two- and six-fold for breast cancer and two- and forty-fold for ovarian cancer.
Michael J. Hall, MD, MS, associate professor of medicine in the Department of Clinical Genetics at Fox Chase Cancer Center and Allison W. Kurian, MD, MSc associate professor of medicine at the Stanford University Medical Center, co-authored the paper, which appears in JCO Precision Oncology.
“Improved technology and increased access have made it possible to identify a broader range of genetic mutations associated with increased cancer risk, but it has been difficult to separate risk associated with mutations and risk conferred by strong family history,” said Hall. “Our study shows whether the risk associated with a given gene mutation is high or low, which will help guide decisions about whether medical intervention is warranted.”
Running complementary analyses on a real-world sample of more than 95,000 women with and without cancer, Kurian and Hall found that their analyses showed similar results. Hall said that it was important to confirm the findings with different approaches.
The study is a step toward adding more precision to the rapidly expanding field of genetic testing. It also found several new associations of breast and ovarian cancer to genes that had not been previously detected in studies with smaller sample sizes.
“As more patients with cancer and at risk of cancer get access to genetic testing, we will gain a more comprehensive view of which genes have an impact on cancer risk and how large those risks are. Some genetic mutations will necessitate increased screening, but others may be low enough that we don’t need to do more than standard prevention and early detection,” Hall said.