Should I have my genes tested if my mother or grandmother had breast or ovarian cancer?

Our genetic counselor at the Nancy N. and J.C. Lewis Cancer & Research Pavilion is available to answer questions about your family history and risks

For more information about our genetic counseling program,  visit our website or reach Jacob South at 912-819-5749 or email southj@sjchs.org.

We inherit a lot of traits from our parents – eye color, hair color, height, facial features. We also could be inheriting a greater risk of getting certain diseases, including cancer.

Cancer is a genetic disease in that it is caused by certain changes to genes that control the way our cells function, especially how they grow and divide. About 75 to 85 percent of cancer is sporadic and due to certain lifestyle or environmental factors and aging, says Jacob South, MS, CGC, genetic counselor at the Nancy N. and J.C. Lewis Cancer & Research Pavilion.

Inherited genetic mutations play a role in the remaining percentage of cancer cases. Researchers have associated mutations, for example genetic changes, in specific genes with several hereditary cancer syndromes, which are disorders that may predispose family members to certain cancers, especially including breast, ovarian, colon, uterine, pancreatic, melanoma and prostate. 

“Individuals with hereditary cancer syndromes are born with a predisposition, a genetic mutation that puts them at higher risk of getting cancer,” South says. “We have two copies of every gene. For individuals who carry an inherited genetic mutation on one copy, there still has to be an environmental insult to cause the ‘second hit’ in the ‘normal’ copy of the gene for cancer to happen.”

There are 10 genes that if altered increase the risk for ovarian cancer, and at least 16 that are now known to increase the risk for breast cancer, South says. Two of the more well-known genes are BRCA1 and BRCA2. Mutations in either gene are related to the condition called Hereditary Breast and Ovarian Cancer Syndrome.

BRCA1 was discovered in 1993 and BRCA2 a few years later. The BRCA genes produce tumor suppressor proteins. These proteins are very important for DNA repair.

“Because they are important in DNA repair, if an individual did not have working copies of either gene, the individual would be susceptible to gaining additional mutations which can eventually lead to abnormal cell division or cancer,” South says.

The average lifetime risk of breast cancer for women is about 12 percent, according to breastcancer.org. For women who have an abnormal BRCA1 or BRCA2, the lifetime risk of developing breast cancer is between 45 to 65 percent.  Similar, women with a mutated BRCA gene have a lifetime risk of 20 to 40 percent to develop ovarian cancer compared to the general population risk of 2 percent.

How do I know if I should have my genes tested?

Genetic counseling is available to anyone with personal and/or family history of cancer at the LCRP. Genetic counseling referral should be considered for anyone with a family history of one or more of the following:

• Anyone of Ashkenazi Jewish ancestry with breast, ovarian, or pancreatic cancer at any age.
• Anyone with a cancer diagnosis and one or more of the following:
  • A blood relative with a known mutation in a gene that increases cancer risk
  • Breast cancer at or before the age of 50
  • Triple-negative breast cancer at or before the age of 60
  • Ovarian, fallopian tube, or primary peritoneal cancer at any age
  • Male breast cancer at any age
• Anyone with breast cancer at any age and one or more of the following:   
  • A blood relative with a known mutation in a gene that increases cancer risk
  • An Ashkenazi Jewish ancestor
  • A close blood relative with breast cancer before age 50
  • A close blood relative with ovarian cancer
  • A second primary breast cancer
• A blood relative with a known mutation in a gene that increases cancer risk
• A blood relative with two or more primary breast cancers
• Two or more relatives with breast cancer on the same side of the family with at least one diagnosed before age 50
• A blood relative with ovarian cancer
• A close blood relative with breast cancer before age 45
• A blood relative with male breast cancer
• Two or more close blood relatives with breast cancer with at least one diagnosed before age 50
• Anyone with a personal or family history of three or more of the following, especially if any of the cases are diagnosed before age 50:
  • Pancreatic cancer
  • Prostate cancer
  • Melanoma
  • Sarcoma
  • Adrenal cancer
  • Brain tumors
  • Leukemia
  • Uterine cancer
  • Thyroid cancer
  • Kidney cancer
  • Diffuse gastric cancer
  • Colon cancer

It’s important to point out that cancer cases must all be on the same side of the family. A close relative is defined as a first, second or third degree relative. The National Society of Genetic Counselors defines first-degree relatives as parents, siblings and children; second-degree relatives as grandparents, grandchildren, aunts and uncles; and third-degree relatives a great-grandparent, great-aunt/uncle or a first cousin.

What is testing like?

Patients who wish to meet with South can expect to spend an hour with him reviewing medical and family history to look for features that are suspicious for certain hereditary cancer syndromes. South can help patients determine if they qualify for testing if they are uncertain.

Testing is quite simple, South says. It’s requires a blood draw. Your blood will be drawn here and sent to a lab where DNA will be extracted from white blood cells. The DNA is purified and special enzymes target pieces of DNA for examination. A new technique called Next Generation Sequencing is used to read the DNA.

“If you are interested in genetic counseling, just ask. I am available for people to ask me questions,” South says. “The process is not scary or difficult. It’s me asking information about yourself and your family, discussing your risks and any suspected hereditary conditions, and ultimately, helping you make decisions regarding testing and care recommendations.”

South prefers a physician referral, but self-referrals are accepted. Genetic testing is covered under the Affordable Care Act; although, some insurance companies have grandfathered plans or other exclusions that may require out of pocket expenses for the patient. South recommends checking with your insurance provider to find out if any costs would be associated with testing. There are multiple resources available to help pay for genetic testing.

What if I have a mutated gene and am at higher risk of developing breast or ovarian cancer?

Genetic counseling and testing identifies high-risk patients so medical personnel can better tailor care based on test results and associated cancer risks, South says.

Positive test results may indicate what caused an individual’s cancer. This information may also be helpful for determining cancer treatment recommendations and possibly for eligibility for clinical trials.

If you are tested and do not have cancer but results indicate a mutated gene, there are options to significantly lower your risk of getting cancer.

For example, a drug called Tamoxifen has been shown to be a proven risk-reducing medication. If a healthy, premenopausal woman takes it for five years, it will reduce the lifetime risk of breast cancer by as much as 50 percent or cut the risk in half, South says. Another option is a prophylactic bilateral mastectomy, which is a surgical procedure that removes both breasts. This may be a difficult decision and several social factors may be taken into account, especially age, relationship status and motherhood; however, high-risk patients who choose this option reduce their risk of breast cancer by 90 to 95 percent.

Along the same lines, women at high-risk of developing ovarian cancer can reduce their chances by 98 percent by removing their ovaries and fallopian tubes.

“Greater than 50 percent of patients I see are already affected with cancer. I’d like to increase the number of patients referred from the healthy population,” South says. “This is an important goal because we don’t prevent anything if we are not testing people who don’t have cancer also.”

For more information about our genetic counseling program, visit our website or reach Jacob South at 912-819-8679 or email southj@sjchs.org.