3 Things You Should Know about Genetic Testing for Breast Cancer
More and more women are getting genetic testing for breast cancer predisposition. When popular actress Angelina Jolie underwent a preventative double mastectomy after she learned she had a high risk of developing cancer, due to a BRCA1 mutation, she brought a lot of awareness to this issue.
“When a mutation is found, that knowledge is very powerful,” Karen Huelsman MS, LGC, certified genetic counselor at the TriHealth Cancer Institute, explains. Before getting started, however, there are a few things you should know.
#1: Only About 10 Percent of Breast Cancers are Truly Inherited with a High-Risk Gene
This means a gene mutation inherited from either parent typically occurs in about 10 percent of cases. The most common genetic mutation is in BRCA1 and BRCA2 genes. There are standard criteria to determine who is a good candidate for testing. Red flags typically include:
- Early age at diagnosis (under 50)
- Having related cancers such as ovarian or pancreatic (or a family history of these)
- Having rarer cancers such as ovarian or male breast cancer (or a family history of these)
BRCA1 and BRCA2 are genes that suppress tumors in humans, and when they have mutations, they do not suppress tumors like they should. So people with these mutations are at a higher risk of getting cancers such as breast, ovarian, prostate, melanoma and pancreatic.
#2: Don’t Ignore Your Dad’s Family History
Karen always reminds people that their father’s history is equally as important as their mother’s. So if the grandma on your dad’s side of the family had breast cancer, for example, don’t overlook that.
For this reason, Karen says to “take advantage of the older relatives in your family, who are available for storytelling, and collect that information."
#3: There are Other Genes that can Cause Increased Breast Cancer Risk – Looking beyond BRCA1/2
Panel testing, which tests multiple genes for mutations at one time (not just BRCA1 and BRCA2 genes), has become more available for those who have a family history of cancer, particularly when the range of cancers could be related to more than one or two genes. Testing multiple gene panels can allow a greater chance to pinpoint the genetic cause.
These panels give results more quickly and can be more cost effective, too. But sometimes panel testing can lead to unexpected results. “A woman comes in with indications for inherited breast cancer testing, but finds out there’s actually a gene for inherited colon cancer in her family, which is good to know, but it’s just unexpected,” Karen explains.
While it’s beneficial to find out you’re predisposed to developing a cancer sooner, rather than later, the challenge is that learning you are at a high risk, unexpectedly, for developing another type of cancer, can add unanticipated stress to your life.