By Kathy O’Brien MS, LCGC and Kylie Boehler, MS, LCGC Genomic Services, Advanced Diagnostics

October 2, 2019 Better Health

October is a time when the leaves begin to change and we are surrounded by the beautiful fall colors. But perhaps the most important color for October is pink.  About 1 in 8 women in the United States (roughly 12%) will develop breast cancer in their lifetime. According to US breast cancer statistics, 268,600 new cases of breast cancer are expected to be diagnosed in women in 2019.1 Breast cancer is more common among women, but it also strikes about 1 in 883 men.2

Hereditary risks can lead to breast cancer
What can we do to reduce the likelihood of developing cancer? Certainly a healthy lifestyle is important for all of us. Knowing your family history can also be critical to identifying cancer before it develops. All cancer is due to genetic changes and anyone can develop cancer. Yet some families have a higher risk due to an inherited predisposition. About 5%-10% of breast cancer is due to inherited genetic changes that can be passed down from parent to child. Changes in the BRCA1 and BRCA2 genes are the most frequent cause of hereditary breast cancer. Changes in other genes like CDH1, CHEK2, PALB2, PTEN, STK11, TP53, and others confer an increased risk too.

Having an inherited predisposition to breast cancer does not mean you have cancer or that you will develop cancer. It does, however, mean there is a greater chance of developing cancer over your lifetime. For example, women who carry certain changes in the BRCA1 gene have up to a 72% lifetime risk of developing breast cancer,3 and for BRCA2, the risk may be as high as 69%.3 This is significantly higher than the general population risk of 12%. While breast cancer is a major risk faced by those with a change in BRCA1 or BRCA2, there are increased risks for other cancers like ovarian, prostate, pancreatic, and melanoma.

Family traits to consider
There are some signs that suggest an inherited predisposition to cancer may run in your family. If any of the following apply to your family, you should speak with your healthcare provider.

  • If you or your family member were diagnosed with cancer before age 50
  • If you were diagnosed with ovarian cancer at any age
  • If you or your family member were diagnosed with more than 1 type of cancer
  • If you have 2 or more relatives on the same side of the family with the same type of cancer
  • If you are Jewish with a personal or family history of cancer
  • If you or your family member have a rare type of cancer, like male breast cancer
  • If you have a family member with a known genetic change in a cancer-causing gene

Options for carriers of genetic changes
Knowing if you carry a change in a gene associated with a higher risk of developing cancer allows you and your doctor to discuss your options. Options can include earlier screenings, more frequent screenings, risk-reduction treatments, and more. Increased screening can lead to earlier cancer detection, and early detection improves chances of survival. Cancer survival has increased over the years. This may be in part due to better screening and earlier detection.

Testing for inherited cancer genes like BRCA1/2 is available at many laboratories. Not all laboratories, however, may be conducting the same type of testing. It is important that you and your doctor know the testing being conducted at the laboratory you choose. Healthcare providers can call a laboratory to ask questions about how their testing is performed. They can also ask what is included in the test, and may even get input on the best test to order. Also, because there are genes besides BRCA1 and BRCA2 that increase the risk for breast cancer, you and your healthcare provider should decide whether single-gene testing or a panel of multiple genes is most appropriate for you. Research on inherited cancer genes is ongoing. Other genes carrying a risk of breast cancer may still be discovered, which means testing options may change over time.

This month is the perfect time to take a moment to be aware of your breast health and your family history. If you have any concerns about your personal or family history, or have questions about genetic testing, talk with your healthcare provider.

  1. https://www.breastcancer.org/symptoms/understand_bc/statistics
  2. https://www.cancer.org/cancer/breast-cancer-in-men/about/key-statistics.html
  3. https://www.ncbi.nlm.nih.gov/pubmed/?term=28632866