Be proactive in assessing BRCA risk
About 1 in 8 U.S. women will develop invasive breast cancer in their lifetime. An estimated 255,180 new cases of invasive breast cancer are expected to be diagnosed in the U.S. this year, along with 63,410 new cases of non-invasive (in situ) breast cancer.
For women in the U.S., breast cancer death rates are the second-highest, behind lung cancer. Besides skin cancer, breast cancer is the most commonly diagnosed cancer among American women.
And women are not the only ones affected by breast cancer. About 2,470 new cases of invasive breast cancer are expected to be diagnosed in men in 2017. A man’s lifetime risk of breast cancer is about 1 in 1,000.
On average, women with a BRCA1 mutation have a 55-65 percent lifetime risk of developing breast cancer. For women with a BRCA2 mutation, the risk is 45 percent.
The gene mutations are inherited from one’s mother or father, and mutations of the BRCA1 and BRCA2 genes are the most common. An increased ovarian cancer risk is also associated with these genetic mutations.
In men, BRCA2 mutations are associated with a lifetime breast cancer risk of about 7 percent. BRCA1 mutations are a less frequent cause of breast cancer in men.
Breast cancer incidence rates in the U.S. began decreasing in 2000 — dropping by 7 percent from 2002 to 2003 alone. One theory is that this decrease was partially due to the reduced use of hormone replacement therapy (HRT). A 2002 study called the Women’s Health Initiative suggested a connection between HRT and increased breast cancer risk.
Still, about 40,610 women in the U.S. are expected to die in 2017 from breast cancer, though death rates have been decreasing since 1989.
In women under 45, breast cancer is more common in black women than white women. Overall, black women are more likely to die of breast cancer. For Asian, Hispanic, and Native-American women, the risk of developing and dying from breast cancer is lower.
A woman’s risk of breast cancer nearly doubles if she has a first-degree relative (mother, sister, daughter) who has been diagnosed with breast cancer. Less than 15 percent of women who get breast cancer have a family member diagnosed with it.
For the other 85 percent, these occur due to genetic mutations that happen through the aging process and life in general, rather than inherited mutations.
The most significant risk factors for breast cancer are gender (being a woman) and age (growing older).
The BRCA gene test is a blood test that uses DNA analysis to identify harmful changes (mutations) in either one of the two breast cancer susceptibility genes — BRCA1 and BRCA2.
BRCA1 and BRCA2 genes produce tumor suppressor proteins. These proteins help repair damaged DNA and, therefore, play a role in ensuring the stability of the cell’s genetic material. When either of these genes is mutated or altered, such that its protein product either is not made or does not function correctly, DNA damage may not be repaired properly. As a result, cells are more likely to develop additional genetic alterations that can lead to cancer.
Specific inherited mutations in BRCA1 and BRCA2 increase the risk of female breast and ovarian cancers, and they have been associated with increased risks of several additional types of cancer.
Together, BRCA1 and BRCA2 mutations account for about 20 to 25 percent of hereditary breast cancers and about 5 to 10 percent of all breast cancers. In addition, mutations in BRCA1 and BRCA2 account for around 15 percent of ovarian cancers overall. Breast and ovarian cancers associated with BRCA1 and BRCA2 mutations tend to develop at younger ages.
Mutations in BRCA1 and BRCA2 increase the risk of several cancers in addition to breast and ovarian cancer:
- BRCA1 mutations may increase a woman’s risk of developing fallopian tube cancer and peritoneal cancer.
- Men with BRCA2 mutations, and to a lesser extent BRCA1 mutations, are also at increased risk of breast cancer (9). Men with harmful BRCA1 or BRCA2 mutations have a higher risk of prostate cancer.
- Men and women with BRCA1 or BRCA2 mutations may be at increased risk of pancreatic cancer.
- Mutations in BRCA2 (also known as FANCD1), if they are inherited from both parents, can cause a Fanconi anemia subtype (FA-D1), a syndrome that is associated with childhood solid tumors and development of acute myeloid leukemia.
- Mutations in BRCA1 (also known as FANCS), if they are inherited from both parents, can cause another Fanconi anemia subtype.
Several genetic tests are available to detect BRCA1 and BRCA2 mutations. DNA (from a blood or saliva sample) is needed for mutation testing. The sample is sent to a laboratory for analysis. It usually takes about a month to get the test results.
However, because BRCA1 and BRCA2 gene mutations are relatively rare in the general population, most experts agree that mutation testing of individuals who do not have cancer should be performed only when the person’s individual or family history suggests the possible presence of a mutation.
In 2013, the U.S. Preventive Services Task Force recommended that women who have family members with breast, ovarian, fallopian tube, or peritoneal cancer be evaluated to see if they have a family history that is associated with an increased risk of a mutation in one of these genes.
The Affordable Care Act considers genetic counseling and BRCA1 and BRCA2 mutation testing for individuals at high risk a covered preventive service. People considering BRCA1 and BRCA2 mutation testing may want to confirm their insurance coverage for genetic tests before having the test.
Some of the genetic testing companies that offer to test for BRCA1 and BRCA2 mutations may offer to test at no charge to patients who lack insurance and meet specific financial and medical criteria.
If you have a family history of BRCA1 and BRCA2 mutations, talk with your doctor. Discuss your concerns and testing options and plot a plan to be proactive in preventing or treating breast cancer.