Cancer involves mutations, or changes, in genes. In most people affected by cancer, these genetic changes happen after birth later in life. In Hereditary Cancer, the cancer is caused by a genetic mutation that the person was born with. Some cancers, such as breast, ovary and colon tend to be hereditary, but that doesn’t mean that you will develop a cancer in one of these areas if you have an immediate family member that has experienced the disease. Not all genetic mutations will develop into cancer, however, the mutation will increase the chance that the person will have a higher risk of developing cancer.
Only 10% of all breast cancer cases are thought to be hereditary. Some of the factors that increase the occurrence of hereditary breast cancer are breast cancer before age 45, male breast cancer, cancer in both breasts and many cases of breast and/or ovarian cancer on one side of the family. If you have two relatives from the same side of your family with breast cancer, your risk of getting the disease can be increased. However it does not mean that you will definitely get breast cancer. You also must keep in mind that the risk for hereditary cancer can be passed on from your mother or your father. You must look at both sides of the family.
The two hereditary mutations that are looked at for breast cancer are BRCA1 and BRCA2. The test for these two genetic factors are done by taking a blood sample. Both of these BRCA mutations (BReast CAncer 1 and 2) are associated with breast and ovarian cancers.
So what factors should you consider when thinking about genetic testing? The age and onset of breast cancer. What other types of cancer are present. What other family members have/had cancer and their relationship to you. When you meet with a genetic counselor, they will go over your family’s medical history and information. This will include first-degree relatives, such as your parents, siblings and children. second-degree relatives like grandparents, aunts and uncles and your third-degree relatives or cousins.
Genetic testing can help a breast cancer patient make decisions about types of treatment and follow-care. A woman with the one of the BRCA mutations may decide to have both breasts removed completely to help reduce the risk of recurrence. Having your healthy breasts or ovaries removed to prevent cancer is called a “prophylactic surgery” and many women who test positive for the genetic mutations decide to go that route. They may just decide to take Tamoxifen to lower their risk.
Not only can women take advantage of risk reduction techniques based on the results of their genetic testing, there are also increased surveillance tools that can help high risk individuals with early detection. Magnetic Resonance Imaging (MRI) and ultrasound are two tools that can be combined with a mammogram to detect breast cancer in its most treatable stage.
Not every person who carries a genetic mutation will develop cancer. You must remember that genetic testing does not detect breast cancer and it will not tell you if you will get breast cancer in your lifetime. The decision to participate in genetic testing is very personal and there is no right or wrong choice in making the decision to have it done.