Deborah Krakow, MD
The known heritable conditions that pose an additional risk of developing ovarian cancer include a mutation in the BRCA1/2
gene, Lynch syndrome, Gorlin syndrome, and multiple endocrine neoplasia type 1 (MEN1), said Deborah Krakow, MD.
Krakow, professor and chair, Department of Obstetrics and Gynecology, professor of orthopaedic surgery and human genetics, University of California, Los Angeles, discussed the patient populations who should undergo testing and the spectrum of possible results.
OncLive: What did your presentation on genetic counseling focus on?
I focused on the genetic basis of ovarian cancer in a heritable form. These are patients who have breast or ovarian cancer because they inherited a mutation from one of their parents. It accounts for approximately 10% of individuals who get ovarian cancer. The major genes that are involved are BRCA1/2 and some rare [conditions], including Lynch syndrome, Gorlin syndrome, and MEN1.
How accurate are prediction models in determining who should get genetic testing?
It is a very good question. If your family history includes a firstdegree relative who has ovarian cancer and you have either ovarian or breast cancer, you should get tested for the known high-risk genes. A patient who is Ashkenazi Jewish and is diagnosed with ovarian cancer, even without a known family history of breast or ovarian cancer, should be tested. Approximately, 1% to 2% of Ashkenazi Jewish women have the same mutation in BRCA1. What is interesting is that all populations report changes in BRCA1/2
, so it is not unique to one population. However, it has been enriched in the Ashkenazi Jewish population.
Is a negative result always accurate?
If you get a negative result that comes from a reputable lab, then you can rest assured that you don’t carry BRCA1/2
or whatever the gene in question is.
What is an unknown significance result indicative of?
We all don’t look the same. Some of us have red hair and some of us have blonde hair. Those [traits] are based on changes in our genome that encode for making the hair protein a different color. When we sequence a large gene like BRCA1
, the sequences will not be the same in everyone. Therefore, when patients who have ovarian cancer all have the same change in the BRCA1
gene, like Ashkenazi Jewish women who are missing 2 letters, we know that has to be real. It’s not a coincidence that so many people who have ovarian cancer have the same change.
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