Do you have a strong family history of cancer? A new tool can help you detect potential problems earlier.
Testing more genes
In 2013, genetic counselors began using a new approach to testing individuals. The multi-gene panel testing, which tests up to 60 genes at once, looks for mutations that could increase a person’s risk of developing a hereditary cancer syndrome, such as breast or ovarian cancer.
In the past, a woman with a strong family history of cancer would have her personal and family history assessed by a genetic counselor, then the counselor would test one gene at a time to search for genetic mutations.
But testing mutations in dozens of genes at once allows genetic counselors to broaden their detection abilities of gene mutations that could be explained by someone family’s history, said Jody Wallace, coordinator of clinical genetic services with St. Elizabeth Healthcare.
“We may order a 21-gene panel now because all of those genes are associated with some form of familial cancer risk,” Wallace said.
Who should be tested?
This new form of genetic testing is most helpful to women who are first seeking genetic counseling because of a strong family history of cancer, or to women who tested negative for BRCA1 or BRCA2 mutations in the past, but, because of their histories, are good candidates for further testing.
“Even if you tested negative for BRCA mutations years ago, you may still have a genetic factor in your family that raises your risk for cancer and warrants additional screenings,” Wallace said.
If you’re interested in multi-gene panel testing, consult a trained genetic counselor who can order and properly interpret your results. He or she will collect a blood sample, which will be sent to a lab; results usually are available within three weeks.
What the results mean
Results of multi-gene panel testing can take three forms: positive, negative or a variant of unknown significance.
If your results are positive, it means a mutation was detected in one of your genes. A positive result tells your genetic counselor which gene showed a mutation and exactly which mutation it is, allowing him or her to tell you your cancer risk during your lifetime. A positive result helps determine management recommendations such as more, or earlier, mammograms and breast MRIs, and whether other members of your family should be tested as well.
If your results are negative, it means no mutations were detected in the genes tested. But your genetic counselor could still make management recommendations based on your family history.
If your results show a variant of unknown significance, it means a mutation has been identified, but while the mutation isn’t proven to cause cancer, it isn’t proven to be benign either.
Variants of unknown significance are one limitation of genetic testing.
“The problem with panel testing is the more genes we include on the panel, the higher the chance we’re going to get a variant of unknown significance,” Wallace said, “but if you have a strong family history of cancer, this test if very helpful.”
