The science behind cancer and our DNA
Receiving a breast cancer diagnosis changes everything. If you ask any woman who hears the words, “we found breast cancer,” most are shocked despite family history and/or personal risk factors.
In 2019, an estimated 268,600 new cases will be diagnosed. Mammograms are detecting tumors and calcifications earlier. These along with leading-edge technology and evolving science are providing more weapons to fight this disease.
With the advancements made in genetic testing, breast, ovarian, or other cancer patients and their families are becoming more empowered and educated in treating a potential cancer diagnosis. They say, after all, knowledge is power.
About Cancer and Genetics
Cancer is caused by a change in, or damage to (also known as a mutation), a “tumor suppressor” gene. This change causes the gene not to work right.
These tumor suppressor genes act as the brakes of our cells. They stop our cells from growing when our body senses that there is something wrong. This allows the body to repair that cell or to kill it. When this doesn’t happen, and a damaged cell is allowed to continue growing, this can lead to cancer.
We each have two copies of every tumor suppressor genes. (One we get from our mother and one we get from our father.) Cancer forms when both copies of the tumor suppressor genes stop working.
Most cancers occur by chance due to multiple personal, environmental and/or genetic risk factors. These risk factors over time wear down the tumor suppressor genes and cause them to fail.
In some families, however, it does not appear to be by chance when several members have a diagnosis of cancer. Determining whether or not there is an inherited gene mutation is critical not only in the treatment/taking the next steps for those already diagnosed, but also to educate younger generations who may wish to exercise their options once armed with the facts.
Genetics and our family medical history can be complex – both in understanding what it means for our health and the ways in which we can use that information to make decisions that help us live our best lives. When it comes to breast cancer and the genetic link, having a genetic test may be one way for a person to become more proactive in their own health journey.
Understanding Genetic Risks with Genetic Counseling
At UPMC in Central Pa., genetic counselor Meagan Smith, MS, LCGC, works in concert with a specialized team of genetic counselors, nurses, surgeons, oncologists, and social workers. They help a patient explore their options for prevention, early detection, and possibly treatment for cancer.
Genetic testing is a personal choice. While it is helpful for those whose family members have an inherited risk of developing a specific disease, the results are not necessarily black and white or a crystal ball. Why? Because having an inherited risk does not always mean you will receive a cancer diagnosis.
What it does mean is that you were born with a change in your DNA which increases your risk of developing certain cancers. Also, not having this identifiable change does not mean that you are not at risk of developing cancer. We still have to determine your risk of cancer based on your personal and/or family history.
In fact, only 5 to 10 percent of all cancers are “inherited” or due to a change in a gene that is passed down from their mother and/or father. While most people have heard of the BRCA1 and BRCA2 genes, we now know that these two genes only account for 25 to 50 percent of those inherited causes of breast and ovarian cancers.
With advances in genetic technology, scientists have now identified more than 20 genes that are also known to increase the risk of breast and ovarian cancers. It is important to note that these same 20 genes can also increase the risk of developing other cancers such as prostate, pancreatic, melanoma, colon, uterine etc.
So, how do you know if you would benefit from genetic testing? Genetic testing is recommended when your family history puts you in the category of “increased risk.” These include:
- Two or more people on the same side of the family have the same type and/or related types of cancer
- Cancer was diagnosed in a family member at age 50 or younger
- A family member’s cancer is in paired organs (both breasts, both kidneys, etc.)
- A family member has a very rare cancer or tumor (male breast cancer, ovarian, pancreatic, metastatic prostate, etc.)
- A single person in your family has more than one type of cancer
- Cancer appears in three or more generations
- Your ethnic background (such as Ashkenazi Jewish ancestry)
- Genetic Counseling Steps
Genetic Counseling Steps
If a family history exists, genetic testing can help determine if the patient has a gene mutation known to put them at an increased risk of developing cancer. Again, an inherited risk does not always mean you will receive a cancer diagnosis. It simply means that you were born with increased risk of developing certain cancers.
When getting genetic counseling and/or testing, a person can expect the following:
- You will meet with a certified genetic counselor to put together a detailed family history.
- The genetic counselor will also explain what role your personal and family history plays in your risk for cancer.
- You will learn about steps that may help you reduce your risks for certain cancers. This may include potential screening recommendations and, in some cases, risk-reducing medications.
- If you meet testing guidelines, the genetic counselor will discuss the different testing options that are available, the risks and benefits of genetic testing, and the possible test results.
- The genetic counselor will also discuss how these possible tests results can impact your personal medical management, as well as your family’s care.
- All recommendations are shared with your family physician.
The genetic counselor will also discuss how these possible tests results can impact your personal medical management, as well as your family’s care.
All recommendations are shared with your family physician.
For more information about your family’s risk and to schedule a time to meet with a genetic counselor, call 717-724-6784.