The Genetics of Breast Cancer
You've probably heard that the risk of any woman developing breast cancer is 1 in 10 by the time she is 80 years old. But for 5 to 10 percent of women who get breast cancer, this risk is much higher (up to 85 percent over a lifetime). The risk is higher for this small group of women because they are born with an inherited change (mutation) in a cancer-causing gene that makes them more likely to develop breast cancer. As you read this information about breast cancer, please keep in mind that only 5 to 10 percent of all breast cancer is hereditary.
Genes are found on our chromosomes. You received half of your chromosomes from your mother and the other half from your father. Each chromosome is composed of hundreds to thousands of genes. Genes are the instructions that make us who we are. Each gene is composed of a series of amino acids that must be linked together in a particular order to make a specific protein that has a specific function in your body.
diseases, such as heart disease, diabetes or cancer. Genes also tell your body which proteins to make to meet your body's needs and when to stop making proteins because you have enough. While there are many kinds of genes, we'll talk about two kinds that play a significant role in triggering cancer: genes that encourage cell growth (oncogenes) and genes that suppress or block tumor growth (tumor suppressor genes). Oncogenes kick the cell's "grow" message into high gear. When tumor suppressor genes don't do their jobs, they contribute to cancer because they no longer act as "brakes" to turn off cell growth
Be aware that even if you choose to have both breasts removed, you still could develop cancer from other cells in your chest wall. Talk over your fears, concerns, and choices with your health care team. One piece of information that may help to determine whether you could have a hereditary risk for breast cancer is your family's history of cancer. Click here to find a genogram that you can fill in with information to discuss with your doctor and genetics counselor.
A genogram shows your family history. You'll want to know the kinds of cancers that your relatives had, the ages at which they had cancer, and whether your female relatives were diagnosed before or after menopause (usually around age 50). There isn't a right answer to the question of whether you should go through a test to determine whether you have one or more of the recently recognized gene mutations for breast cancer. Take your time and gather as much information as you need. You are the best source of deciding what's right for you.