American women have a one in eight chance of developing breast cancer. Early detection via mammograms or other imaging is crucial for improving the chances that a person with breast cancer can get treatment at an early stage when cancer is easier to treat.
Some individuals have an inherited genetic mutation that increases risk for cancer. The genes BRCA1 and BRCA2 have altered many women’s approach to breast health and screening. There are additional breast cancer-related genes, such as ATM, CHEK2, PALB2, TP53, that can also cause a high risk for breast cancer.
Testing for mutations in these types of genes can help people who are at higher risk for cancer tailor their screenings and take a proactive approach to cancer prevention and detection. It also helps to alert doctors that a patient will require closer monitoring.
Experts caution that genetic testing is not a one-size-fits-all approach. Only between 5 and 10 percent of all cancers are hereditary, As such, genetic counseling is not for everyone. It is also a personal choice.
“While some women feel that testing will help them plan, others feel that it will create unnecessary anxiety,” says Carrie Costantini, MD, an oncologist at Scripps MD Anderson Cancer Center and Scripps Clinic. “It is a personal decision.”
At Scripps, a physician referral is required to meet with a genetic counselor to discuss genetic disorders and testing.
Below, Dr. Costantini answers frequently asked questions about genetic testing.
BRCA1 and BRCA2 are tumor suppressor genes that can help prevent irregular cells from growing. But when they themselves are mutated, they cannot do their job properly. As a result, tumors cells can grow. A BRCA1 or 2 mutation is hereditary — a person is born with it. It cannot develop or change during a person’s lifetime and is almost always inherited from someone’s mother or father.
People most likely to have gene mutations are those who:
- Have had breast cancer before menopause
- Have family members with breast or related cancers — such as ovarian, prostate, or pancreatic cancer
- Have multiple cancers
- Have male breast cancers
- Know there is a gene mutation in their family.
Generally, patients should discuss if they fit any of the criteria with a genetic counselor. They should have testing only if they plan to use the information to adjust their cancer screening. That may mean lifestyle changes, frequent screening or preventive surgery.
See our recommended testing guidelines for BRCA and other hereditary breast cancer genes below. If you select any of these risk factors, you should consider testing.
Testing is either through a blood or saliva sample.
It means there is a genetic mutation that may put a patient at an increased risk to develop cancer. It doesn’t mean that he or she is going to get cancer. Conversely, a negative result doesn’t mean he or she will never get cancer. Currently, only about 10 percent of breast cancers are attributed to inherited gene mutations.
Environmental factors also contribute to cancer, so even with a negative result, regular mammograms are recommended.
For those with a gene mutation, prophylactic mastectomies (removing the breast tissue) and/or oophorectomies (removing the ovaries) can prevent additional cancers. Additional cancer treatments are known to be more effective in patients with these gene mutations.
For many patients with a mutation, more preventive measures will be taken. It’s recommended that women with a hereditary breast cancer gene mutation undergo screening every six months rather than every year and incorporate breast MRIs annually. It can also alert other family members that they could be at risk for cancer.
Use the following guidelines when considering genetic testing. In most cases, people who need genetic counseling fit into one of two groups:
Group one includes people with:
- Two or more close family members with the same type of cancer
- The same type of cancer in several generations of a family
- Ashkenazi (Eastern or Central European) Jewish ancestry and family history of breast or ovarian cancer.
Group two includes people who have a cancer diagnosis and want to learn if it’s genetic. It is usually recommended for people who have:
- Developed cancer at an earlier stage than usual for their disease
- Been diagnosed with two or more separate cancers
- Developed a rare type of cancer, such as male breast cancer or medullary thyroid cancer
- Family history of the same or related type of cancer.
If you have additional questions about your potential risk for developing breast cancer, or hereditary cancer testing, gene testing, talk to your primary care doctor to see if a referral to genetic counseling is appropriate.