October 16, 2017
The National Human Genome Research Institute estimates that there are about 20,000-25,000 genes in the human genome. These genes are responsible for making each of us who we are — they dictate physical traits such as eye color and bone structure, influence personality features such as temperament and intellect, and determine many aspects about our health, including the lifetime likelihood for cancer. The BRCA genes are two of the most notable genetic links to cancer development, and mutations in these genes are strongly linked to breast, ovarian and prostate cancer.
“BRCA1 and BRCA2 are genes that everyone has, and they play a vital role in protecting us from developing cancer on the cellular level,” said Anna S. Victorine, MS, CGC, a genetic counselor at Provenance Healthcare and affiliated with the Breast Center at Sunrise Hospital and Medical Center. “When someone has an abnormal change in one of these two genes that affect their functionality, we call it a pathogenic mutation. These types of mutations can increase the risk of cancer.”
While researchers are still discovering the many genes and genetic mutations that may contribute to disease development, understanding BRCA is a major step toward cancer prevention.
What are BRCA1 and BRCA2?
BRCA is an acronym meaning “breast cancer gene,” using the first two letters of breast (BR) and the first two letters of cancer (CA). Many BRCA mutations have been observed, and most of them aren’t harmful, or “pathogenic.” However, specific mutations have been identified for both BRCA1 and BRCA2 that increase the risk of cancer in varying ways.
The National Cancer Institute (NCI) reports that 55-65 percent of women with a harmful BRCA1 mutation and about 45 percent of women with a harmful BRCA2 mutation will develop breast cancer by the age of 70. Further, 39 percent of women with a harmful BRCA1 mutation and 11-17 percent of women with a harmful BRCA2 mutation will develop ovarian cancer by the same age.
These statistics are substantially higher than those of women in the general population, wherein about 12 percent will develop breast cancer in her lifetime and about 1.3 percent will develop ovarian cancer.
Men with a harmful BRCA2 mutation are at a greatly increased risk of developing male breast cancer. BRCA1 and BRCA2 mutations are both linked to prostate cancer as well.
While BRCA1 and BRCA2 mutations are uncommon within the general population, it’s recommended that certain people be tested depending on their personal and/or family history. They include those with:
- Breast cancer diagnosed before age 50
- Cancer in both breasts in the same woman
- Both breast and ovarian cancers in either the same woman or the same family
- Multiple breast cancers
- Two or more primary types of BRCA1- or BRCA2-related cancers in a single family member
- Case of male breast cancer
- Ashkenazi Jewish ethnicity
According to the National Cancer Institute, BRCA1 and BRCA2 mutations account for about 20-25 percent of hereditary breast cancers and 5-10 percent of all breast cancers. BRCA1 and BRCA2 mutations also account for 15 percent of all ovarian cancers.
Victorine also notes that people with a history of ovarian cancer and/or multiple relatives with breast cancer on the same side of the family should also be considered for testing. The testing process involves taking a blood or saliva sample.
“The sample is sent to a specialized laboratory that extracts the DNA, reads through the genetic code for errors and then interprets the errors to determine if they pose an increased risk of disease,” Victorine said. It’s recommended that genetic counselors are involved before and after the testing process.
Does testing positive for BRCA mutations affect medical care moving forward?
People who are positive for either BRCA1 or BRCA2 mutations will need to work with their doctors and genetic counselor to create an ongoing action plan moving forward. Victorine also recommends that women get in touch with a breast specialist.
In many cases, patients will need to adopt an aggressive cancer-screening procedure that may include starting at a younger age than the general recommendation and breast MRIs, in addition to mammograms. Some women may consider preventive mastectomies and/or removal of the ovaries.
The Affordable Care Act considers BRCA testing for high-risk patients a covered, preventive service, but patients should confirm with their individual insurance providers prior to having the test. Further, the Genetic Information Nondiscrimination Act (GINA) protects patients who are genetically predisposed to disease from discrimination from their insurance provider.
“This means that someone can’t be dropped or denied coverage just because they have an increased risk,” Victorine said. “In fact, knowing this information can actually be helpful in encouraging an insurance carrier to pay for additional screening measures or preventive surgeries.”
While testing positive for a BRCA mutation is scary, it’s important to remember that it in no way guarantees a cancer diagnosis down the line. Many women with BRCA1 or BRCA2 mutations will never develop cancer within their lifetime. However, it’s important that they, and their families, are aware of the risk so they’re able to take protective measures against it.