breast cancer genetics

After receiving a breast cancer diagnosis, it is natural to wonder if there is a genetic connection, especially if there have been a few cases of breast cancer in your family. Only a small fraction of breast cancer cases, about 10 percent, are considered hereditary. These cases are typically caused by a gene that has mutated (changed) and been passed down to you. Understanding more about this genetic mutation can help you understand your risks for developing hereditary breast cancer.

The Genetics of Breast Cancer

BRCA1 and BRCA2 are the two genes that science currently recognizes as most associated with increased risk of breast cancer. One in 400 people have a BRCA gene mutation. Those who have a BRCA1 or BRCA2 gene mutation have a much higher likelihood of developing breast cancer by age 70.

OHC’s breast surgical oncologists collaborate with a team of cancer genetic specialists to offer high-risk genetic counseling and testing to those at risk for hereditary breast cancer through OHC’s Genetic Risk Evaluation and Testing (GREAT) Program.

Other Genes That Can Increase Breast Cancer Risk

Genetics is an emerging science, and more research needs to be done to completely understand the genetics of breast cancer. While BRCA gene mutations appear to increase risk the most, other genes may play a role in increasing the risk of breast cancers. These include ATM, BARD1, CDH1, NF1, PTEN, RAD51C, RAD51D, STK11, and TP53.

Who Should Have Genetic Testing to Determine Cancer Risk?

It is not necessary for everyone to have genetic testing as part of their routine health evaluations. Genetic testing may be recommended if you or one of your family members (on either side of the family) meet one of the following criteria:

  • Breast cancer diagnosis before age 45.
  • A woman diagnosed with triple-negative breast cancer.
  • A male in the family diagnosed with breast cancer at any age.
  • A female in the family diagnosed with ovarian cancer at any age.
  • Ashkenazi Jewish heritage along with any cancer in your family.
  • Strong family history of multiple cancers including breast cancer, pancreatic cancer, ovarian cancer, or aggressive prostate cancer.

An OHC cancer genetic specialist can provide guidance on risk factors and determine if genetic testing is recommended. Choosing to have genetic testing is an individual decision. Some people prefer not to know. Armed with results, a compassionate counselor will help you formulate a plan of action including cancer screening recommendations and lifestyle changes as preventative measures. They will also explain how results have the potential to affect family members.

You Have a BRCA or Other Gene Mutation. Now What?

Stay on Top of Exams and Mammograms

It is important to realize that having the BRCA gene mutation does not mean you are going to develop cancer. But, it can help you and your doctors stay vigilant and look out for anything abnormal. Your doctor may recommend that you start getting mammograms before the average recommended age and they may also recommend annual breast MRIs.

The National Comprehensive Cancer Network (NCCN) recommends the following for those with a BRCA gene mutation:

  • Regular self-exams.
  • A clinical breast exam every six-to-12 months beginning at age 25. These are often part of an annual gynecologic exam. Talk to your doctor about how often you should have this exam.
  • Annual screening MRI starting at age 25.
  • Annual screening mammogram starting at age 30.
  • Continue breast cancer screenings after age 75 if you choose.

Risk-Reducing Mastectomy

Some women with BRCA gene mutations choose to have a risk-reducing mastectomy (or ovary removal). In this situation, the breast is removed to decrease the chance of developing cancer in the future. It does not guarantee that a woman will never get breast cancer, but it does greatly decrease the chances. This is a very personal decision, and your breast surgeon can help you assess your feelings about these procedures and discuss any surgical options in more detail.

Other Lifestyle Choices to Reduce Cancer Risk

  • Limit alcohol consumption. According to the American Cancer Society, women who have one alcoholic drink a day have a small increase in breast cancer risk (about 7-10 percent) compared with those who do not drink. Women who have two-to-three drinks a day have about a 20 percent higher risk.
  • Maintain a healthy weight.
  • Physical activity- OHC recommends 30 minutes of exercise per day for five days each week.
  • Women who have not had children or who had their first child after age 30 are at a slightly higher risk for breast cancer.
  • Breastfeed if that is an option.
  • Some birth control methods use hormones that might increase breast cancer risk.
  • Discuss the possible risks and benefits of using hormone replacement therapy (such as estrogen) with your doctor as hormone use can increase the risk of breast cancer.
  • Do not smoke or use nicotine products. Heavy exposure to secondhand smoke can also increase breast cancer risk.

OHC believes that genetic risk evaluation is a critical component of quality cancer care and prevention. Genetic risk evaluation can ultimately lead to fewer cancer diagnoses, and cancer discovered in its earlier stages typically has better treatment outcomes. To request an appointment with an OHC cancer genetic specialist, call 1-888-649-4800. Individuals do not have to be existing OHC patients to request a consultation, and the process is relatively simple.