Sunday, November 4, 2007

If Cancer Runs in Your Family: Understanding Hereditary Risk and Genetic Testing

A genetic risk for cancer means that certain cellular mutations that increase an individual’s risk for developing cancer are passed down through generations, giving each new family member who inherits a cancer susceptibility gene a potentially increased risk for developing certain cancers. These hereditary mutations are responsible for about 5–10 percent of cancer incidence.
Although hope remains that research in the field of gene therapy may someday find a way to repair these gene alterations, for now we are at least able to identify gene mutations through genetic testing—an important step in understanding your genetic susceptibility for cancer and the first step in managing your risk. However, even though you may gain important information from a genetic test, the decision to be tested should be made carefully. Here are some things to consider as you decide whether genetic testing is an appropriate choice for you:
Genetic Counseling
Because the implications of genetic testing and its findings for you personally and within your family are potentially very complicated, you may wish to seek the guidance of a genetic counselor. Testing and its results are complex—for example, if a genetic mutation is revealed, it is not certain that an individual will develop the associated cancer nor is the absence of a mutation a guarantee that an individual will not develop cancer. Furthermore, genetic testing does carry certain risks and limitations, which should be considered before you undergo such a procedure. A genetic counselor can help you understand these issues as well as the following:
Whether genetic testing is the right choice for you
Your results and their particular significance for you
How to share your results with other family members, as these findings may indicate that they are also at risk for the same hereditary mutation
Is Genetic Testing Right for You?
Potential candidates for genetic testing have one or more of the following characteristics:
Diagnosed with early-onset cancer*
Experienced more than one cancer diagnosis
Have a strong family history of cancer or a family history of rare cancers**Consult with your physician to determine if you’ve been diagnosed with early-onset cancer or whether you have a strong family history of cancer and to learn which types of cancer are consider rare cancers.
What You Can Learn from Testing
If you do undergo genetic testing, you may learn the following:
Your high-risk status will either be confirmed or you’ll be able to rule out the presence of a genetic alteration found in other family members.
If you do test positive, you can increase your screening practices, which may detect cancer at an early and most treatable stage.
Some cancers may be prevented entirely with preventive surgeries.
Limitations and Risks of Genetic Testing
In some circumstances genetic tests don’t offer any benefit. For example, if you may be at genetic risk for a type of cancer for which there is no reliable screening method or effective treatment, knowledge of this alteration would be of little or no use. Additionally, because these tests are only predictive and not definitive, there are no absolute answers about the likelihood that you will develop cancer. As well, though these tests are technologically sophisticated, they are still not 100 percent accurate, allowing the possibility that they will fail to identify a cancer-causing mutation or that a gene may be incorrectly identified as mutated. Risks to further look into include the potential for employment or insurance discrimination based on high-risk status for developing cancer and the potential anxiety for the entire family that the knowledge of an inherited mutation may cause.
For more information about genetic testing, go to

No comments: