Genetic testing for cancer is done for different reasons. It is used to predict the risk for cancer in a patient with a family history. Some may want to figure out whether they are carrying a cancer-causing gene that can be passed on to their children.
Even cancer patients may be recommended genetic testing to understand whether they are at risk for other types of cancers and also to decide the right course of treatment.
But whether a patient or family member has been advised by a doctor to go for genetic testing or they have decided to do it by themselves, the process is usually fraught with worry and doubt. This is where genetic counseling or a discussion with a genetic counselor helps.
A genetic counselor is either a doctor with a degree in medical genetics or a person with a specialized post graduate in genetic counseling. They advise patients about the nature of a number of inherited diseases, cancer being one of them.
Cancer risk assessment with a genetic counselor
Genetic counselors act as advocates for the patient and help them discuss options with their oncologist or onco-surgeon. They recommend the specific genetic test required for the type of gene mutation that the patient is likely to have. Ideally, the counselor and the patient’s doctor should be in agreement about the genetic test which is most appropriate.
The counselors also interpret the reports of these tests and help patients deal with the medical and psychological implications, especially if the result is positive.
Dr. Aparna Dhar, Genetic Counselor, Core Diagnostics explains how genetic counseling works by sharing the case of 20-year-old Geeta Varma (name changed) who is a breast cancer patient.
While discussing her medical history, Geeta did not reveal that her father passed away due to male breast cancer. Like many patients who do not share information about medical issues related to their reproductive or sexual health because they are afraid of being judged, Geeta did not share this information due to shame.
After some psychological counseling, when Geeta finally admitted the cause of her father’s death, she was tested for a specific germline mutation in her genes.
Her younger brother also benefited from the test as they began aggressively screening him for the cancers caused by that specific gene mutation. This included both male breast cancer and prostate cancer, which meant he had to go for periodic breast mammograms and ultrasonography for the prostate. Geeta’s medication and treatment also could be planned and monitored better thanks to the correct diagnosis of the type of cancer.
Dr. Aparna Dhar walks us through some of the common questions or concerns that most people have regarding genetic testing for cancer.
At what age can one go for genetic testing for cancer?
Genetic testing to predict the risk for cancer (prior to the appearance of any symptoms) is usually advised to those who are 18+ unless a parent or doctor requests it before that age.
What is my cancer risk? How can I decide whether I need a genetic test?
As you are aware, it is important to reveal your complete medical history and medical records as the first step to assess whether you are at risk for specific inherited cancers.
A genetic counselor will help determine whether you have genetic risk factors based on your condition, age and family’s medical history. There will be questions regarding:
- Your detailed medical history including hospitalization and surgeries
- Types of cancers in the family and extended family
- Any conditions such as colon polyps that are linked to certain cancers
- Prior genetic test reports of family members, if any
Then certain risk assessment tools are used to determine whether you require further screening or testing.
Is the cancer prediction risk 100% accurate?
The genetic counselor assesses your risk based on your medical history. You must understand that it is based on certain predictive algorithms, which determine whether you have a relatively higher risk of getting cancer than the general population, statistically speaking.
After the counseling session, it is also possible to find out that your risk is not as high as you think so you might not require genetic testing for cancer.
Does a positive genetic test report mean I will get cancer?
The dreaded c-word evokes fear and anxiety. But, it is important to understand that the risk is determined for a specific genetic mutation, which means you are at a high risk for developing a specific type or types of cancers. Your genetic counselor will be able to guide and advise you on how to cope with the stages of grief that you might go through and also to deal with the medical implications of the test. You should discuss the possible screening options, preventive surgeries, and other treatment options. You can also find out whether further testing of any kind is needed for you and your family members.
But, nobody will be able to guarantee that you will or won’t develop cancer.
If I have a genetic mutation, does it mean my family is at risk for cancer?
As you saw in Geeta’s case, it is important to screen certain family members for specific gene mutations. However, this does not mean future cancers are certain or will always occur. To understand your family’s medical needs it is important to discuss the implications of the test with the genetic counselor.
Does a negative result mean that I won’t get cancer?
Genetic testing for cancer is used only to predict the risk for cancers that are inherited through gene mutations and not the cancers that are caused by lifestyle and other factors. After you have a sigh of relief, you need to speak to your doctor about the next steps.