Hereditary Cancers: what you need to know

29th Oct 2019

As we come to the last days of October and Breast Cancer Awareness Month, I wanted to end by talking about Hereditary Breast and Ovarian Cancer. I touched on this a bit in my mastectomy story, and Angelina Jolie wrote a moving piece about her experience in the New York Times several years ago.

The following information is taken from the FORCE (Facing Our Risk of Cancer Empowered) website, which is a great resource about hereditary breast and ovarian cancer.:

Hereditary cancer risk can be passed down from either side of the family, so when looking at your family medical history, you need to consider relatives on both your mother’s and your father’s sides of the family. Most cancer is not due to inherited mutations. About 10-15% of cancers are hereditary, depending on the type of cancer.

Hereditary cancers are those caused by an inherited gene mutation that increases the risk for one or more types of cancer. ‘Hereditary Breast and Ovarian Cancer Syndrome’ (also known as HBOC) is most commonly caused by mutations in one of two genes: BRCA1 and BRCA2. These mutations increase the risk for breast, ovarian, pancreatic, prostate, melanoma and possibly other cancers. Mutations in other genes are also associated with hereditary breast and/or ovarian cancers including PALB2, CHEK2, ATM, BRIP1, and RAD51C, and RAD51D. People with the following personal or family history should discuss the possibility of genetic testing with a genetic counselor: 

If you or a relative have had any of the following:

  • ovarian, fallopian tube, or primary peritoneal cancer
  • breast cancer at age 50 or younger
  • two separate breast cancers
  • a type of breast cancer called “triple negative breast cancer”
  • male breast cancer
  • pancreatic cancer
  • prostate cancer at age 55 or younger or metastatic prostate cancer (cancer that spread outside the prostate)
  • Eastern European Jewish ancestry and any of the above cancers at any age

Or, if more than one family member on the same side of your family has had:

  • breast cancer
  • ovarian, fallopian tube, primary peritoneal cancer
  • prostate cancer
  • pancreatic cancer

Several other types of cancer syndromes have been identified, each with a particular set of signs. Some of these syndromes increase risk of breast cancer including Cowden syndrome (PTEN mutation), Li Fraumeni syndrome (TP53 mutation), CDH1 mutations, and STK11 mutations. Lynch Syndrome is a hereditary cancer syndrome that increases risks of many cancers, including colon, uterine, and ovarian.

If you have any of this in your family, or know someone who may, please forward this along to them.

If you are in the Pittsburgh area, both AGH and UPMC have high-risk breast cancer programs with genetic counselors. The National Society of Genetic counselors has a searchable directory to help you find a genetic counselor by zip code.

Now, cancer is unfortunately a fairly common disease, so most families will have some members who have had cancer. The cause of most cancer is not known, but we do know that most cancer is not due to a single inherited change in a gene. Cancer that is not due to an obvious inherited pattern is called “sporadic cancer.” It is believed that most— perhaps 90%—of all cancers are sporadic. The chance of having a BRCA gene mutation is around 1 in 400. So just because you or someone in your family has had cancer, doesn't mean you need genetic testing. However, if there have been a number of cancers within your family -especially within the parameters listed above- then I would encourage you to contact a genetic counselor.

Other hereditary mutations have been identified that don’t increase the risk for breast or ovarian cancers but do increase the risk for other cancers (colon cancer is one of them). Any family with multiple individuals with the same type of cancer, very young onset cancers, or rare cancer types should consult with a genetics specialist regarding whether the cancer in family might be hereditary.

Hereditary cancers occur when a person is born with a change or mutation in a single copy of a protective gene pair. Because people with an inherited mutation have only one working copy of a protective gene, damage to that remaining gene may occur in fewer steps and over a shorter period of time. The medical community uses the term ‘genetic susceptibility’ to describe the fact that people with an inherited mutation have an increased risk for cancer.
The change does not increase the risk for every type of cancer and not everyone who is born with a gene change will develop cancer; risks vary according to the exact mutation that was inherited. Many other factors affect the risk of cancer in someone born with a gene mutation. Scientists do not know all the factors that determine whether or not a person with a gene change will develop cancer over the course of their lifetime.

If you'd like more information:
Bright Pink
Young Survival Coalition
Right Action for Women (Christina Applegate Foundation)

Photo by Louis Reed on Unsplash