Download Testing for Hereditary Cancers

Testing for Hereditary Cancers -
Breast or Ovarian
Breast cancer is common among American women, affecting about 1 in 8 women. Ovarian cancer is not as common as breast cancer affecting 1 in 70 women. Only 5 to 10% of all breast and ovarian cancer cases are hereditary. The most common hereditary breast and ovarian cancer condition is called Hereditary Breast and Ovarian Cancer Syndrome. It is important to remember that most breast and ovarian cancer is not hereditary.
How is hereditary breast and ovarian cancer syndrome inherited?
Chromosomes, containing hereditary information are in every cell in our body. Each chromosome is made up of thousands of genes. Genes are units of genetic information (DNA) that act as instructions for making the things that help our bodies work properly. A change in this genetic information can interfere with proper body functions by causing the gene to no longer work. These gene changes are called mutations.
BRCA1 and BRCA2 are genes that control cell growth and division. If there is a mutation in either of these genes, they can no longer control cell growth and division. A BRCA1 or BRCA2 gene mutation increases the chance that cancer will develop. People with a mutation in either of these genes tend to be diagnosed with cancer at an earlier age and are also more likely to develop breast cancer in both breasts.
What are the possible benefits of BRCA1 and BRCA2 testing?
One of the major advantages of learning BRCA gene test results is reduced uncertainty about the risks of cancer for a person and their family. The testing may allow doctors to alter medical care in order to decrease the risk of breast and ovarian cancers. If the BRCA gene testing is negative, cancer screens may not need to occur as often.
What are the possible risks of BRCA1 and BRCA2 testing?
Before testing, these risks should be considered:

The process of genetic testing may be emotionally difficult regardless of whether a BRCA1 or BRCA2 mutation is found. 
If a mutation is found, this result may indirectly provide information about other family members who may choose not to be tested. 
Costs for the cancer screening and prevention options may or may not be covered by health insurance. 1
What are the chances of inheriting an altered BRCA1 or BRCA2 gene?
BRCA1 and BRCA2 are both inherited in an autosomal dominant fashion. Autosomal means that both men and women can inherit a BRCA mutation. Dominant means that it only takes one BRCA gene mutation to cause the increased chance of having cancer. All people have two copies of each BRCA gene, one from each parent. 
If a person has a parent with a BRCA1 or BRCA2 mutation, he or she may either inherit that parent’s BRCA gene with the mutation or that parent’s working BRCA gene. 
The person has a 50% chance of inheriting the altered BRCA gene and a 50% chance of not inheriting the BRCA gene mutation. 
If the gene is not inherited, the person would have the same risk for getting cancer as the general public. How are BRCA1 and BRCA2 mutations detected?
A blood sample or mouthwash sample is taken to test for BRCA1 and BRCA2
mutations. If a mutation is found, other family members can be tested for that mutation. Is it possible to receive an unclear BRAC test result?
Yes. About 5-10% of people who have complete gene testing for both the BRCA1 and BRCA2 genes receive an unclear result. This means that the person has a gene change but it is not clear if it causes an increased risk for cancer. What if testing does not detect an altered BRCA1 or BRCA2 gene?
A negative result means that a BRCA1 or BRCA2 mutation is not found. It might mean that there is a BRCA1 or BRCA2 gene mutation that cannot be found by current testing methods. This is a limitation of many genetic tests. It could also mean that a different gene is responsible for the cancers in the family. It is also possible that the cancers in the family are not hereditary. What if testing reveals that a person has inherited an altered BRCA1 gene?
Women who inherit a BRCA1 mutation have:

An increased chance for developing breast and ovarian cancers. 
A 50-85% risk of having breast cancer by age 70. 
A 40-60% risk for ovarian cancer by age 70. A woman who has already had breast cancer in one breast and is found to have an altered BRCA1 gene has an increased risk for breast cancer in her other breast.
2
Men with a BRCA1 gene mutation have an increased risk for developing prostate cancer - about 16% by age 70. What if testing reveals that a person has inherited a BRCA2 mutation?
Both men and women who inherit a BRCA2 mutation have an increased chance for developing breast cancer:

Women have about the same risk of developing breast cancer as found with BRCA1. 
The chance for a male with a BRCA2 mutation to develop breast cancer is 5-10%. 
Women with a BRCA2 mutation have a 10-20% risk for developing ovarian cancer by age 70. 
Men have a 16% lifetime risk for developing prostate cancer. 
Men and women also have slightly increased risks for developing pancreatic cancer, throat cancer, stomach cancer, and melanoma skin cancer.
If a person has an altered BRCA gene, what are the options for cancer screening and prevention?
If a woman is known to have a BRCA gene mutation, she should have careful screening to help find cancers at the earliest possible stage when they are most easily treated. This means:

Having yearly breast imaging with mammography and MRI.

Having breast exams by a doctor every six months.

Doing monthly breast self-exams. Screening for ovarian cancer is not very effective. However, women may choose to receive ultrasounds, together with pelvic examinations and certain blood tests, in an attempt to help find ovarian cancer early. Other options include medication or surgery.
Men with a BRCA mutation should:

Have a yearly screening for prostate cancer. 
Perform a monthly breast self-exam to detect any changes.

Have an annual breast exam by their doctor. Understanding and making decisions about genetic testing can be a challenge. If you would like more information, call the Cancer Risk Program at 614-546-4330.
Dev. 1/2007, Rev. 1/10, 1/13
\\Mcehemcshare\netit patient education$\Mount Carmel Handouts\Cancer\Testing for Hereditary Cancers - Breast or Ovarian.doc
©Mount Carmel 2013
3