Download Gynecological Issues: Hereditary Breast and Ovarian Cancer

Did you know???
1 in 40 Ashkenazi Jews have a BRCA
mutation, regardless of family history---and most don’t know!
What does this mean????
A Little Bit of Genetics:
BRCA 1 and BRCA 2 are genes that, when working normally, are tumor
suppressor genes, meaning they prevent cancer. When there is a mutation in these genes they can’t work to
prevent cancer and cancer is more likely to develop. There are thousands of individual gene abnormalities that
can cause a mutation on the BRCA 1 or BRCA 2 gene. These mutations are inherited in an autosomal
dominant fashion from a parent who carried this mutation—either father or mother. What that means is that if
your parent had a BRCA mutation, you have a 50% chance of inheriting this mutated gene.
In the general population, the risk having a BRCA mutation is not very common--about 1 in 300-500 people.
However, the chance of having a BRCA mutation in Ashkenazi Jews is 1 in 40, or 2.5%. This is called the
incidence of the genetic mutation, or how common it is to carry the mutation. The incidence of carrying a
BRCA mutation is the same in both Ashkenazi men and women. **(see below re: founder mutations)
Why are BRCA Genes Important: The penetrance of a gene mutation refers to a person’s risk
of developing the disease from the genetic mutation, in this instance cancer. BRCA mutations are highly
penetrant genes. Women who carry a BRCA mutation have up to an 90 % lifetime risk of breast cancer, and up
to a 50 + % lifetime risk of ovarian cancer. Also, BRCA positive women tend to develop breast and ovarian
cancer at younger ages; For example, 20% of BRCA 1 positive patients develop ovarian cancer before the age
of 50. Men who are BRCA positive have up to approximately a 15% risk of developing prostate cancer, as well
as an increased risk of male breast cancer. Pancreatic cancer and Melanoma can also be seen in BRCA carriers.
Who Should Be Tested for BRCA mutations: Medical organizations in the past have
recommended that Ashkenazi Jewish men and women be tested for a BRCA mutation only if there was a family
history of breast, ovarian or pancreatic cancer. Newer studies, however are questioning this approach. Why?
Because we see the same BRCA incidence in Ashkenazi Jews without a family history of cancer. The risk of
carrying a BRCA mutation is 1 in 40 in Ashkenazi Jews is independent of family history. And even
without a family history, in people who are BRCA positive, the possibility of developing a BRCA related
cancer is still very high.
Why do I want to know: We want to identify people who are carriers before cancer develops. If
a person is BRCA positive, there are guidelines for increased surveillance to help diagnose cancer at its earliest
and most treatable stage, and procedures recommended to decrease the risk of developing these cancers. This
includes breast MRIs beginning at age 25 and both yearly MRI/mammogram at age 30. Risk reduction
surgery is also recommended, usually by age 40. This includes bilateral mastectomy with reconstruction as well
as removal of the ovaries and tubes, around age 40, or whenever child bearing is complete. It may sound
drastic, but it is better to prevent a cancer than to treat a cancer, especially in the case of ovarian cancer.
Ovarian cancer is very difficult to diagnose, and when it is diagnosed is it is frequently at an advanced stage.
What about other Jewish genes that increase the risk of cancer:
There are other genes in Ashkenazi and Sephardic Jews that can increase their risk of cancer.
For example, there is a gene that is carried by up to 10% Ashkenazi Jews that increases the risk of colon cancer.
Another gene more common in Ashkenazi Jews increases the risk of Lynch Syndrome, a syndrome associated
with colon, endometrial and ovarian cancers. There are also mutations on various genes that are more common
in the Sephardic Jewish population. For example, 1 in 80 Sephardic Jews carry a mutation on the ATM gene,
which is associated with an elevated risk of breast cancer.
Why Color Genomics: There are a handful of specific genetic labs that have acceptable methodology.
Color Genomics is one of them. Their unpaid advisory board is comprised of well-known medical thought
leaders, including Mary-Claire King, one of the researchers who first identified the BRCA gene in the 1990s.
And for $249 for a 30 gene panel associated with hereditary cancer syndromes, including BRCA 1 and 2, Color
Genomics has found a very cost effective way identifying Ashkenazi Jews who carry mutations that could
increase their risk of developing cancer.
Founder Mutations: Founder mutations are gene mutations that are more specific to an ethnic group. On the
BRCA 1 and 2 genes there are about 3500 known mutations. Only 3 of these are founder mutations. If an
Ashkenazi Jew is positive for a BRCA mutation, ~ 85 % will be one of these 3 mutations. That means if an
Ashkenazi Jew is checked only for the founder 3 mutations, we will miss about 15 % of the mutations they
could be positive for. There is a BRCA founder mutation in Sephardic Jews, as well, but the incidence is closer
to that of the general mutation, or about 1/300. In this gene panel, all mutations in the BRCA genes are
analyzed.
Additional Information and Links:
Video:
Pink and Blue: Colors of Hereditary Cancer: https://www.youtube.com/watch?v=SftAvdvYBm4
Readings:
Elizabeth Wurtzel, 9/15/15, New York Times: “The Breast Cancer Gene and Me”,
https://www.nytimes.com/2015/09/27/opinion/sunday/elizabeth-wurtzel-the-breast-cancer-gene-andme.html?_r=0
Roni Caryn Rabin, 9/4/14, New York Times: “Study of Jewish Women shows Link to Cancer without Family
History” https://www.nytimes.com/2014/09/05/health/05cancer.html
Additional information available at:
Brightpink.org
Facingourrisk.org
Sharsharet.org