Study Shows Families Don’t Understand Genetic Test Results Or Their Implications
A study done by researchers at Fox Chase Cancer Center shows that many relatives of patients who undergo testing for a gene linked to breast and ovarian cancers misinterpret the results, and less than half of those who could benefit from genetic testing say they plan to get tested themselves—despite the fact that knowing your genetic status may help catch the disease in its earliest stages. The study results were presented at the 2013 San Antonio Breast Cancer Symposium.
"People don't always understand genetic information, so there's confusion," says study author Mary B. Daly, MD, PhD, chair of the Department of Clinical Genetics at Fox Chase. "Family members are either not understanding what they're hearing, not realizing it has implications for them, or they're not hearing it at all."
For a long time, Daly says she "naively" assumed that, once one family member knew whether or not they carried genes linked to breast and ovarian cancers—known as BRCA1/2—their entire family would understand the result, and what it meant for their own genetic risk. "Over time, we realized that wasn't happening, or it wasn't happening very well."
Some genetic information is straightforward, says Daly. For example, when a woman learns she carries BRCA1/2 that means her parents, siblings and children may also carry the gene. But there are more "indeterminate" results, which are harder to interpret, she adds. If a woman with a strong family history of breast and ovarian cancers tests negative for the BRCA1/2 genes, that does not mean her relatives are not at risk, says Daly—her siblings could still carry the gene, or there could be additional genes present that predispose them to cancer that clinicians don't yet know how to test for.