BRCA Genetic Testing: Yes or No?

Patient Expert

So your mom has just been diagnosed with breast cancer, and now you're worried. What if it runs in the family? Could it be genetic? How would you know?

There's been a lot of talk in recent years about genetics, and the role your body's genes play in cancer. Many genetic influences on cancer have yet to be proven; researchers THINK they exist, but don't have the data to back it up. But there's one that's absolutely for sure: the connection between a couple of specific gene mutations - the so-called BRCA1 and BRCA2 genes - and breast cancer.

Great There's a test that can examine your genes, and tell you if your risk of breast cancer is higher than that of the general population. Let's all have our genes tested, right?

I mean, who wouldn't want to know if her risk of getting breast cancer is maybe 10 times higher than normal?

Not so fast. Before breast cancer anxiety drives you to the doctor demanding to be tested, you need to understand whether genetic testing is right for you. Actually, very few women meet the baseline standards for testing for the BRCA1 or BRCA2 genes.

Your mother has (or had) breast cancer - is that enough to suspect a genetic mutation?


How about if your sister was diagnosed with breast cancer in her 30s - is that enough to suspect it may be genetic?


What about if cancer has run in your family for generations? Or your dad is battling of prostate cancer, your sister has leukemia, and your grandmother died of breast cancer? Or, there's something about being of Jewish descent - if you're a Jewish woman, are you a prime candidate for genetic testing?

No, no, and probably not.

According to most published guidelines, there are specific conditions that, if met, suggest a woman would benefit from genetic testing for breast cancer. (FYI: first-degree relatives include parents, siblings, and children. Second-degree relatives are grandparents, aunts/uncles, and nieces/nephews.)

You're a good candidate for genetic testing if you have:

-A personal history of breast cancer diagnosed at age 40 or younger;
-A personal history of bilateral breast cancer (cancer in both breasts), diagnosed at age 50 or younger;  
-A personal history of both breast and ovarian cancers;
-Two or more first-degree relatives diagnosed with breast cancer before age 50;
-Three or more first- or second-degree relatives diagnosed with breast cancer (any age);
-A male relative with breast cancer;
-A first- or second-degree relative with both breast and ovarian cancers;
-A first-degree relative with bilateral breast cancer (cancer in both breasts);
-Two or more first- or second-degree relatives with ovarian cancer;
-A relative who tested positive for BRCA1 or BRCA2 ;
-Ashkenazi (Eastern European) Jewish ancestry, with or without a family history of breast or ovarian cancer.*

*Some doctors narrow this down further to include being Ashkenazi Jewish with a first-degree relative with breast or ovarian cancer; or with two second-degree relatives, from the same side of the family, with breast or ovarian cancer.

Going by those guidelines, only a tiny percentage of the American population is at enough risk to warrant genetic screening. If you have breast cancer, your risk of carrying a mutated gene is only about 2.4%. If you don't have breast cancer, the risk drops to less than 1%.

So, while watching a close relative go through breast cancer is bound to make you worry about your own risk, take heart. The chance of your genes predisposing you to cancer is less than 1%.

Bottom line: You almost certainly don't need genetic testing. Just keep to your regular mammogram schedule; report any breast changes to your doctor, and you're being fully responsible about your breast health.