Hereditary Breast Cancer

Gayle Patel
Certified Genetic Counselor, Texas Oncology

When I meet new people and introduce myself as a genetic counselor, I often get blank stares or funny jokes about making designer babies (no, I don’t do that!).  I think of myself as an educator, a translator and a support person for families with a hereditary disease.  A genetic counselor helps families take a closer look at their family tree, determine if genetic testing is right for them and interpret the often complex results so that they can take proactive steps in their healthcare.   At Texas Oncology, our team of genetics experts provides genetic evaluations and testing to identify families that are at high risk for cancer so we can detect cancers early and prevent future cancers from occurring.  While testing for hereditary cancer syndromes has been available for many years now, awareness of the BRCA or breast cancer genes, increased in 2013 when actress Angelina Jolie announced that she is a BRCA1 mutation carrier.  Most people have now heard of the BRCA genes, but I often get questions about cancer genetic testing and the BRCA genes.  Here are some of the most common questions:

Cancer can be inherited?

Did you know all cancer is genetic but that only some cancer is hereditary, or inherited?  Cancer is caused by changes, or mutations, in genes that control the way our genes work, especially in genes that control how cells grow and divide.  As we live our lives, we can acquire mutations in our DNA, most of which occur by chance or due to environmental exposures.  If a gene that is responsible for cell growth acquires a mutation, then that gene no longer works and cells will grow uncontrollably.  This is cancer.   The majority of cancer just happens by chance but, about 5-10% of all people are actually born with a mutation in an important gene that can lead to an increased risk for cancer.

What are the BRCA Genes?

The BRCA genes are tumor suppressor genes. Their job is to prevent uncontrolled cell growth and abnormal cells from turning into cancer.  Every person has two copies of the BRCA1 gene and two copies of the BRCA2 gene, and most people have functioning copies. A person with a mutation in a BRCA gene is often called a BRCA carrier.  Individuals with BRCA mutations have higher lifetime risks for cancer than other people because the gene can’t do its job.

How many people have a BRCA mutation?

It is important to remember that everyone has the BRCA genes, but it is rare to have a mutation in a BRCA gene.  About one in 400 people have a mutation in a BRCA gene.   BRCA mutations are more common in individuals of Ashkenazi Jewish Ancestry, where about one in 40 people have a mutation.  It is estimated that close to one million people in the United States have a BRCA mutation, but less than 10% are aware that they have a mutation that increases their risk for cancer.

What types of Cancer do the BRCA Mutations Cause?

The BRCA genes have long been known as the breast cancer genes, but we now know that these genes can cause a variety of types of cancer.  The risk for breast cancer in a woman with a BRCA mutation is about 66-67%.  This is much higher than the risk for breast cancer in women without a BRCA mutation, which is about 12%.  We also know that women with BRCA mutations who have had one breast cancer are at significantly higher risk for a second breast cancer.  The risk for ovarian cancer is also increased between 12-45% over a lifetime.  We also know that the risks for male breast cancer, prostate cancer, pancreatic cancer and melanoma are increased for individuals with a mutation in BRCA1 or BRCA2.  It’s important to remember that men carry BRCA mutations as well and are at increased risk for cancer!

What do you do differently if you have a BRCA mutation?

When Angelina Jolie announced that she has a BRCA mutation, she also shared her decision to have a risk reducing mastectomy.  I often get asked if this is the only option for BRCA carriers. Fortunately, the answer is no. We now have many options to discuss with BRCA mutation carriers, including increased surveillance for cancer, medications to reduce risk, and risk reducing surgery.

Surveillance:  Increased breast cancer screening for women with a BRCA mutation includes monthly self-breast exams, clinical breast exams with their doctor twice a year, annual mammograms, and annual breast MRIs.  Currently, there are no known effective screening techniques for ovarian cancer.   Men with BRCA mutations should have clinical breast exams and prostate cancer screening.

Risk Reducing Medicines:  Chemoprevention, or medications that reduce cancer risk, can also be considered.  There are medications such as tamoxifen that are known to reduce the risk for breast cancer.  Also, oral contraceptives are known to reduce the risk for ovarian cancer.   A discussion of the risks and benefits of these types of medications is important for women who are considering these medications.

Surgery:  Women with BRCA mutations can consider having a bilateral mastectomy, or removal of both breasts, with or without reconstruction, to reduce breast cancer risk.  Given that the risk for a first and SECOND breast cancer is higher in BRCA carriers, this is an option that significantly reduces the risk for breast cancer.  This is a major surgery, and BRCA carriers should have a discussion with their healthcare provider to decide if this is the right procedure for them.

Since there currently are no effective screening tests for ovarian cancer, women with BRCA mutations are recommended to have their ovaries and fallopian tubes removed, to reduce their risk of ovarian cancer.  This is called a bilateral salpingo-oophorectomy.  Typically, a salpingo-oophorectomy is recommended after completion of childbearing (usually around age 35-40).  Not only does this procedure reduce the risk for ovarian cancer, but it also reduces the risk for breast cancer and has been associated with a 77% reduction in overall risk of death.

BRCA carriers have many difficult decisions to make, but knowing your genetic status can help you feel empowered to make decisions to reduce risk and prevent cancer.

How does a BRCA mutation run in a family?

Mutations in the BRCA genes are typically inherited from a parent and are passed down from generation to generation.  A person who has a BRCA mutation has a 50% chance of passing the mutation on to each of their children.  These mutations do not skip generations but sometimes appear to, since not all people with BRCA  mutations develop cancer.  Both men and women can have BRCA mutations and can pass them onto their children.

I think I need testing, what should I do?

While there are many people with BRCA mutations, not everyone needs genetic testing.   By reviewing your family history, a genetics professional can help you determine if you need genetic testing and the most appropriate test.  Signs of hereditary breast and ovarian cancer or BRCA mutations are:

  • Ovarian cancer at any age (this includes fallopian tube cancer and primary peritoneal cancer)
  • Breast cancer at age 45 years or younger
  • Two breast cancers in the same woman with one before the age of 50
  • Two family members with breast cancer on the same side of the family, one with breast cancer before 50
  • Male breast cancer
  • Breast cancer at or before age 60 that is “Triple Negative,” or a ER, PR, HER2 negative breast cancer
  • Three or more family members with breast cancer, ovarian cancer, and/or aggressive prostate cancer
  • Ashkenazi Jewish Ancestry and a personal or family history of breast, ovarian, or pancreatic cancer

If you or your family has any of the above features, you should ask your doctor for a referral for a cancer genetic evaluation.

What happens at a genetic evaluation?

A genetic evaluation is conducted by a healthcare provider with specialized training in cancer genetics.  The visit usually takes one hour and involves taking a thorough personal and family history, and a discussion of the risks, benefits, and limitations of testing.  After this evaluation, if genetic testing is warranted, these healthcare providers can coordinate genetic testing (usually a simple blood draw).  Once your test results are received, your provider will help create a personalized management plan, based on your personal and family history and your test results.

How much will testing cost me?

Historically, BRCA genetic testing has been expensive, but the cost of testing is declining. Comprehensive genetic testing for hereditary cancer can cost anywhere from a few hundred dollars to $4,000.  Most insurance companies will cover the testing for individuals with a significant personal and family history.   It is important to have an evaluation with a cancer genetics professional to determine which is the RIGHT test for you and your family, as testing options vary widely.

I’ve already had BRCA testing, so my cancer is not genetic right?

BRCA testing has changed over the years, so depending on WHEN your test was done you may not have had complete BRCA testing.   If you previously had complete BRCA testing and it was negative, it is unlikely that a mutation in a BRCA 1 or BRCA2 gene caused the cancer in your family. But this does not mean there couldn’t be a different genetic cause.  Everyone has about 22,000 genes, and there are additional breast and ovarian cancer genes that have been discovered that we can now test for.  For example, the PALB2 gene, or” Partner and Localizer of BRCA2” gene, can present just like a BRCA mutation and has similar breast cancer risks.   Other breast cancer genes include CHEK2, ATM, PTEN and TP53.  There are also other genes that cause ovarian cancer such as BRIP1, RAD51C and RAD51D.

In addition to identifying new cancer genes, we now have genetic testing technology, called “next generation sequencing” that allows us to look at multiple genes at the same time.  With this new technology AND the discovery of new genes, we are able to offer hereditary cancer panel tests that provide a quick, cost effective view of multiple genes at the same time.  Panel testing has been shown to significantly increase our ability to find a genetic answer for families and create specific management plans, but panel testing is not without its risks.  Panel testing varies widely in what genes are analyzed and can lead to uncertain results.  It is important to see a cancer genetics professional to help decide what panel test is right for you, help you become knowledgeable about the risks and benefits of panel based testing, and guide you through the results and implications for your family.  Families with mutations in other cancer genes also need to consider options such as increased surveillance so that we can find cancer early or prevent it.

Are other types of cancers inherited?

Yes.  Just as there are hereditary causes for breast and ovarian cancer, there are hereditary causes of colon, uterine, stomach cancer, melanoma and other types of cancer.   If you have multiple family members with the same type of cancer, cancers at very young ages, or individuals with multiple cancers, ask your doctor about a genetic evaluation.

Where can I learn more?

If you would like to learn more about Hereditary Breast and Ovarian Cancer or BRCA mutations, visit Facing Our Risk of Cancer Empowered at www.facingourrisk.org or Bright Pink at www.brightpink.org.  You can also learn more about genetic risk assessments in the Austin area through the Texas Oncology Genetic Risk Evaluation and Testing Program at www.texasoncology.com

Gayle is the Director of the Genetic Risk Evaluation and Testing Program (GREAT) at Texas Oncology.  She provides education and operational support to Texas Oncology Providers who participate in the GREAT program.Gayle received her undergraduate training at Trinity University in San Antonio and her Master’s degree in Genetic Counseling at The University of North Carolina, Greensboro.  Prior to being part of the Texas Oncology Team, Gayle was a genetic counselor in a busy genetics clinic for the Seton Healthcare system in Austin, Texas providing prenatal, pediatric and adult genetic counseling for 6 years.

References:

1: Buys SS, Sandbach JF, Gammon A, Patel G, Kidd J, Brown KL, Sharma L, Saam J,Lancaster J, Daly MB. A study of over 35,000 women with breast cancer tested with a 25-gene panel of hereditary cancer genes. Cancer. 2017 Jan 13. doi:10.1002/cncr.30498. [Epub ahead of print] PubMed PMID: 28085182.

2: Daly MB, Pilarski R, Berry M, Buys SS, Farmer M, Friedman S, Garber JE, Kauff ND, Khan S, Klein C, Kohlmann W, Kurian A, Litton JK, Madlensky L, Merajver SD, Offit K, Pal T, Reiser G, Shannon KM, Swisher E, Vinayak S, Voian NC, Weitzel JN, Wick MJ, Wiesner GL, Dwyer M, Darlow S. NCCN Guidelines Insights: Genetic/Familial High-Risk Assessment: Breast and Ovarian, Version 2.2017. J Natl Compr Canc Netw. 2017 Jan;15(1):9-20. PubMed PMID: 28040716.

3: Hartmann LC, Lindor NM. The Role of Risk-Reducing Surgery in Hereditary Breast and Ovarian Cancer. N Engl J Med. 2016 Feb 4;374(5):454-68. doi: 10.1056/NEJMra1503523. Review. PubMed PMID: 26840135.

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