DOES CANCER RUN IN MY FAMILY?
For people who have several close relatives who have been diagnosed with cancer—especially breast or ovarian cancer – the question can be a nagging one. Genetic testing may be able to provide some answers. Although the majority of cancers do not result from genetic abnormalities passed from one generation to another, researchers are discovering more and more inherited genetic alterations that appear to increase risk for cancer.
Two decades ago, researchers discovered that inherited mutations on the BRCA1 and BRCA2 genes were linked to an increased risk of several cancers, most notably breast and ovarian cancer. In the years since, the field of genetic analysis and testing has grown enormously, and genetic links to many more cancers have been discovered, says Sami Diabdiab, MD, a Rocky Mountain Cancer Centers breast cancer specialist and Medical Director of the Genetic Counseling Program at Rocky Mountain Cancer Centers.
“The field of genetic testing has changed a great deal recently,” Dr. Diab says. The changes are the result of a combination of factors, including research breakthroughs and laws that forbid discrimination based on genetic test results, he says.
Dr. Diab offers answers to common questions patients have about genetic testing:
WHO SHOULD HAVE GENETIC TESTING?
Anyone with a strong family history of cancer, such as multiple affected individuals, relatives who were diagnosed with breast cancer under age 45, family history of ovarian cancer, or family members who have had more than one cancer.
In addition, the National Cancer Institute says the following characteristics indicate a possible hereditary cancer connection:
- Several different types of cancer that have occurred independently in the same person
- Young age, such as under 50, at diagnosis
- Cancer that has developed in each organ of a pair, such as both kidneys or both breasts
- Several close blood relatives that have the same type of cancer (for example, a mother, daughter, and sisters with breast cancer)
- Family history of ovarian cancer
- Unusual cases of a specific cancer type (for example, breast cancer in a man)
- The presence of birth defects, such as certain noncancerous (benign) skin growths or skeletal abnormalities, that are known to be associated with inherited cancer syndromes
- Being a member of a racial/ethnic group that is known to have an increased chance of having a certain hereditary cancer syndrome and having one or more of the above features as well.
WHAT IS THE PROCESS OF GENETIC TESTING?
The first step, if you want to schedule testing, is to make an appointment with a genetic counselor, who will do a formal assessment of your personal and family history, and will explain genetic testing and what the results could mean for you. Based on the risk assessment and genetic test results, the genetic counselor and Rocky Mountain Cancer Centers oncologist will meet with you to discuss options for managing your risk including possible screening and preventive options.
IS THE GENETIC TEST PAINFUL?
The test is non-invasive; it’s done through a blood or saliva sample.
WHAT INFORMATION DOES THE TEST PROVIDE?
We’re looking for genetic mutations, or genetic abnormalities in your cancer genes. A positive result means the laboratory found an inherited change in a gene that is associated with a greater risk of developing cancer. A positive result does not mean cancer was detected or that you will get cancer, just that you are at a higher risk.
WHAT TYPES OF CANCERS ARE LINKED TO GENETIC ABNORMALITIES?
A: In addition to breast and ovarian cancer, we now know there are genes related to many types of cancer, including colon, kidney, thyroid, endometrial, and pancreatic, as well as cancers of the eye and neuroendocrine system.
WHAT ARE THE BENEFITS OF KNOWING I HAVE A GENETIC MUTATION?
Depending on the gene abnormality and associated cancers, there are increased screening and preventive options available. Patients with a high risk for breast cancer could opt for earlier and more frequent breast screening or could consider a preventive mastectomy. Even with cancers where surgery isn’t an option, there are steps you can take to lessen your risk and improve the chances of early detection. For colon cancer, you can have colonoscopy once a year and starting at an earlier age, rather than every 10 years starting at age 50. For conditions with an increased risk for thyroid cancer, you could complete a thyroid ultrasound once a year, for example.
WHAT ARE THE COSTS OF GENETIC TESTING?
Genetic testing is much less expensive now because in 2013 the U.S. Supreme Court ruled that genes could not be patented. That opened the door for multiple companies to do the testing, so the cost is decreasing. Also insurance companies have much better coverage for genetic testing now for patients at high risk for cancer.
CAN EMPLOYERS OR MY INSURANCE COMPANY USE GENETIC TESTING INFORMATION AGAINST ME?
No, the federal Genetic Information Nondiscrimination Act, or GINA, enacted in 2008 prohibits insurance and employment discrimination based on genetic test results. There is also a Colorado state law that protects from genetic discrimination.
IF RESULTS ARE NEGATIVE FOR GENETIC ABNORMALITIES, DOES THAT MEAN I HAVE NO CANCER RISK?
No. Only a small percentage of cancers are linked to genetic abnormalities, so interpreting a negative result is just as important as a positive result. That’s why we always follow up with a genetic counselor regardless of the result. We don’t want to give people a false sense of security so they don’t get recommended cancer screenings.