Genetic testing is a powerful tool, and raises many important issues for individuals and their families. The following are frequently asked questions and important information you should know before deciding if cancer risk testing is useful for you.
What is genetic counseling?
Cancer risk genetic counseling entails consulting with a team of health care professionals (usually a genetic counselor, physician or nurse-geneticist) to review personal and family history, help determine cancer risk, and provide recommendations to reduce cancer risk and detect cancer earlier.
What is the role of the genetic counselor?
A genetic counselor will evaluate the likelihood of a genetic trait that is responsible for cancer in an individual or his/her family and help people understand the genetic, medical, psychological and other issues related to genetic testing.
Genetic counseling before genetic testing helps individuals make a truly informed decision about whether testing is right for them. Similarly, genetic counseling after testing helps to explain the meaning and implications of the test result, including determining if further testing is necessary.
What is genetic testing for cancer risk?
Genetic testing for cancer risk is used to determine if a genetic change, called a mutation, is present in genes that predispose persons to developing cancer at an earlier age than would be expected. Having a predisposition to developing cancer does not mean you will definitely develop cancer, but it does increase your risk. Knowing this may enable you and your doctor to make health care decisions to prevent or reduce your chances for cancer.
What are the benefits of genetic testing?
Testing could identify who is at high risk for particular cancers and who is not. A person found to have a cancer-causing mutation could make health care decisions to prevent or lower his or her chances for cancer or help detect cancer at an early stage. A person who does not have the mutation that is responsible for cancer in their family would not need extra healthcare exams and tests and may be relieved to learn that they, and their children, are not at increased cancer risk because of this mutation. Genetic testing may help determine the cause of cancer for you or your family.
How do genes and heredity affect cancer risk for my children?
Genes are made up of DNA, the hereditary blueprint that makes us who we are. We have two copies of each gene. We get our genes from our parents, inheriting one copy of a gene from our mother and another copy from our father. When a parent has a mutation, there is a 50 percent chance of passing on the mutation to each of his or her children, since each child inherits either the normal copy of the gene or the copy with a mutation.
Are all cancers hereditary?
No. In fact, only about five to 10 percent of all cancers are inherited. Most cancers are due to an accumulation of damage to the DNA in our cells. This occurs naturally as we age, with most cancers occurring at older ages (50+). The development of cancer is a multi-step process. This means that several different changes have to occur in the cell's DNA before cancer develops. An individual who inherits a cancer gene mutation is already one step ahead in this process. Thus, fewer steps have to happen before cancer develops, and cancer may be seen at younger ages than otherwise expected.
What could indicate that I might be at hereditary risk for cancer?
Cancer is a common disease. It is expected that families will have one or more relatives with some form of cancer. Nevertheless, several clues exist to suggest hereditary cancer in a family. These clues include:
Cancer at an early age
More than one generation with cancers
Same type of cancer in at least two closely related relatives
Multiple primaries (more than one type of cancer in the same person)
Bilateral disease (cancer occurring in both sides of a paired organ, e.g., cancer in both breasts)
Multifocal disease (many primary tumors arising in the same organ)
Rare cancers clustered in the same side of the family
Breast & ovarian cancer in the same side of the family
Breast cancer that occurs in a male
Colon and uterine cancer in the same side of the family
Multiple colo-gastrointestinal polyps in a young individual (e.g., 10 in a person)
The genes involved with cancer can come from either side of the family. Thus, a cancer gene trait may be passed to a daughter through her father who did not have cancer. Accurately interpreting family history information is an essential aspect of genetic counseling.
What if I don't have much information about my family?
Although a large family may provide more clues to interpreting hereditary risk, many of us have small families or limited information available about our family's past. Sometimes various strategies can be used to find out more information, such as contacting relatives, searching for medical records or obtaining copies of death certificates.
What are the limitations of genetic testing?
Because testing techniques vary, it is important that your genetic counseling team explain the method of testing being used to look for a mutation and the chances that method will find a mutation. Different methods have different levels of sensitivity, and therefore, even with the best technology, in some cases testing may not be able to find an existing cancer-causing mutation for you or your family.
Are my test results confidential?
Test results will be part of your medical record and, as all medical records, they will never be shared with anyone other than yourself without your permission, as the law indicates. If your health insurance company paid for your testing, the insurer could ask for the test result. The pros and cons of disclosing your result to others will be discussed with you. Participation in a research study is strictly confidential, as outlined in the requisite informed consent document provided to all study participants.
What are the psychological effects of testing?
Individuals differ in their thoughts about genetic testing for cancer risk, what risk means to them, and ways to manage risk. They might feel that the knowledge gained from testing, regardless of the test result, helps them to feel less uncertain and to make better health care decisions armed with more knowledge. They might feel relieved to know that a genetic change was responsible for cancer rather than something about their lifestyle or environment. Others prefer not to know, or decide that the information learned from testing would not be useful to them, perhaps in that it would not change their health care management or provide information for other family members.
Genetic testing can also affect family relationships. If a family member has a mutation, a relative who learns that she or he does not have the mutation may feel guilty for being spared. People in whom a mutation is identified may feel a change in self-image, fear of the future, anger, surprise, worry or guilt for possibly passing a mutation on to their children. The inability to identify a mutation in a family could also be upsetting to some people. These are all normal reactions.
Some people seek psychological counseling prior to or after testing to help cope with decisions about testing and the implications of test results.
What about possible discrimination due to having a disease-associated mutation?
There has been concern that people identified as at high risk for cancer could be discriminated against when obtaining or retaining health insurance, disability insurance and life insurance, and when obtaining or retaining employment. Further, having a cancer-prone genetic makeup could lead to social stigma and social discrimination in terms of choice of schools or careers, adoption, and even dating and marriage relationships.
What are the legal protections?
In the past, laws at the federal and state levels offered some protection against discrimination based on genetic testing or family history information; however those laws did not offer unqualified full protection. Recently, the Genetic Information Nondiscrimination Act (GINA) was signed into law and provides the most comprehensive protection against genetic discrimination of any law thus far.
Genetic Information Nondiscrimination Act (GINA) of 2008
: The Genetic Information Nondiscrimination Act (GINA) is a long-awaited piece of federal legislation prohibiting the use of genetic information in health insurance coverage decisions or employment. This legislation prohibits insurance companies from determining health insurance eligibility or premiums based on genetic test results or family history. In addition, GINA prohibits employers from using genetic information in decisions regarding employment, compensation, conditions or privileges of employment. For more information see Hudson et al. New England Journal of Medicine 358: 2661-63, 2008
Health Insurance Portability and Accountability Act (HIPAA)
: In August 1996, HIPAA was signed into law, expressly stating that people who are covered by a group health insurance policy of 50 or more individuals by their employer may not be denied a similar policy due to genetic information or other pre-existing conditions when they change jobs. This law was a first step in providing federal protection against genetic status discrimination. However, it does not protect self-employed individuals or those working for small employers, so the more comprehensive GINA was later passed.
At the state level, California law prohibits prepaid health care plans, self-funded/self-insured employer/employee welfare benefit plans, nonprofit hospital service plans, and life and disability income insurance companies from discrimination based on genetic characteristics to persons unaffected by a genetic-related disorder. Genetic characteristics are defined as a family history of genetic disorders or gene alterations causing or increasing the risk of a disease or disorder.