Genetic testing and your cancer risk
The genes in our cells play important roles. They affect hair and eye color and other traits passed on from parent to child. Genes also tell cells to make proteins to help the body function.
Cancer occurs when cells begin to act abnormally. Changes in genes (mutations) tell the cells to divide rapidly and stay active. This leads to cancer growth and tumors. Gene mutations may be the result of damage to the body or something passed down in the genes in your family.
Genetic testing can help you find out if you have a genetic mutation that may lead to cancer or that may affect other members in your family. Learn about which cancers have testing available, what the results mean, and other things to consider before you get tested.
Genetic mutations; Inherited mutations; Genetic testing - cancer
Which Cancers may be Genetic
Today, we know specific gene mutations that can cause over 50 cancers, and the knowledge is growing.
A single gene mutation may be tied to different types of cancer, not just one.
Genetic mutations are linked with the following cancers:
Signs that cancer may have a genetic cause include:
About Genetic Testing
You may first have an assessment to determine your level of risk. A genetic counselor will order the test after talking with you about your health and needs. Genetic counselors are trained to inform you without trying to guide your decision. That way you can decide whether testing is right for you.
How testing works:
While you may be able to order testing on your own, it is a good idea to work with a genetic counselor. They can help you understand the benefits and limitations of your results, and possible actions. Also, they can help you understand what it may mean for family members, and counsel them as well.
You will need to sign an informed consent form before testing.
What Genetic Testing can Tell you
Testing may be able to tell you if you have a genetic mutation that is linked with a group of cancers. A positive result means you have an increased risk of getting those cancers.
However, a positive result does not mean you will develop the cancer. Genes are complex. The same gene may affect one person differently from another.
Of course, a negative result does not mean you will never get cancer. You may not be at risk due to your genes, but you could still develop cancer from a different cause.
Your results may not be as simple as positive and negative. The test may discover a mutation in a gene that experts have not identified as a cancer risk at this point. You may also have a strong family history of a certain cancer and a negative result for a gene mutation. Your genetic counselor will explain these types of results.
There also may be other gene mutations not yet identified. You can only be tested for the genetic mutations we know about today. Work continues on making genetic testing more informative and accurate.
Who Should Consider Testing
Deciding whether to have genetic testing is a personal decision. You may want to consider genetic testing if:
Testing can be done in adults, children, and even in a growing fetus and embryo.
Possible Benefits of Testing
The information you get from a genetic test may help guide your health decisions and lifestyle choices. There are certain benefits of knowing if you carry a gene mutation. You may be able to lower your risk for cancer or prevent it by:
If you already have cancer, testing may help guide targeted treatment.
Questions to Consider Before Testing
If you are thinking about testing, here are some questions you may want to ask your health care provider or genetic counselor:
Before getting tested, be sure you understand the process and what the results may mean for you and your family.
When to Call the Doctor
You should call your provider if you:
American Cancer Society website. Understanding genetic testing for cancer. www.cancer.org/cancer/cancer-causes/genetics/understanding-genetic-testing-for-cancer.html. Updated May 23, 2016. Accessed August 22, 2018.
National Cancer Institute website. BRCA mutations: cancer risk and genetic testing. www.cancer.gov/about-cancer/causes-prevention/genetics/brca-fact-sheet. Updated January 30, 2018. Accessed August 22, 2018.
National Cancer Institute website. Genetic testing for hereditary cancer syndromes. www.cancer.gov/about-cancer/causes-prevention/genetics/genetic-testing-fact-sheet. Updated April 11, 2013. Accessed August 22, 2018.
Schrader KA, Sharaf R, Alanee S, Offit K. Genetic factors: hereditary cancer predisposition syndromes. In: Niederhuber JE, Armitage JO, Doroshow JH, Kastan MB, Tepper JE, eds. Abeloff's Clinical Oncology. 5th ed. Philadelphia, PA: Elsevier Saunders; 2014:chap 12.
Review Date: 7/26/2018
Reviewed By: Todd Gersten, MD, Hematology/Oncology, Florida Cancer Specialists & Research Institute, Wellington, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.