When to think about genetic testing for members of the family with cancer at a young age.
When a person is diagnosed with cancer in his or her 20s, 30s or 40s, the diagnosis brings another concern with it: “Why the young age?” For parents, siblings and children, another question often arises: “Was there a family connection with cancer?”
It’s not always simply a matter of right and wrong. Many people get diagnosed with cancer at a young age for many reasons and early diagnosis does not necessarily rule out a hereditary cause of the cancer. In some families, a genetic change passed down through the generations can raise the risk of acquiring some forms of cancer. Having their eyes opened to the potential of genetic testing can help families understand their risk levels and make appropriate health care decisions.
A young age may be a significant clue
Cancer is more common with age so when a patient is diagnosed at an unusually young age, this may encourage the doctor to investigate the patient’s personal and family history.This doesn’t mean that all young people who are diagnosed with cancer are suffering from an inherited genetic mutation. Genetic changes that happen in a person’s lifetime over the course of their life can lead to many cancers. Age, environmental exposures, lifestyle, and infections among other things can affect these changes.
How do doctors know if cancer has a genetic cause?
There is no single rule for deciding whether or not an individual should be tested genetically. Physicians tend to focus on the general pattern of cancer in a family.
If an individual gets certain types of cancer at an early age, especially when relatives have had cancer, genetic counselling might be considered. An unusual clue can be the presence of multiple relatives who have developed the same cancer or a related cancer.
If, for instance, breast, ovarian, pancreatic or prostate cancer is in the family history, the doctor may ask if there might be an inherited cancer-predisposition gene.
Other circumstances can also pose questions, including when one individual gets more than one cancer, or when the cancer is rare within a family.
What matters is that a family history is a clue to investigate, not an indicator of inherited cancer.
What is the value of genetic testing?
Genetic testing can identify certain genetic changes in your DNA that may make you more likely to develop certain cancers. The ones that are well-known are alterations in genes like BRCA1 and BRCA2, which may be linked with the development of multiple cancers.
If the genetic test is positive, this does not indicate that the person has cancer and it does not necessarily mean that cancer will develop. Rather, it can mean that it is more likely that the person is at a higher than normal risk.
The information can be useful since it can enable doctors to suggest suitable screening or other risk-reduction measures earlier.
If a person gets a negative result doesn’t mean that he or she has no risk of cancer. Not all cancers and not all genetic factors can be explained by genetic testing.
Why genetic counselling matters?
The prospect of genetic testing can be daunting, especially if the outcome may impact the whole family. That’s why it’s better to test with the proper medical supervision.
A genetic counsellor or specialist will assess whether this testing is likely to be helpful for an individual, and discuss the implications of each possible outcome.
In some cases, close relatives may be offered targeted testing when an inherited mutation is known, to find out if they have the same mutation. This may help to identify relatives that might require additional monitoring from those who do not have the specific inherited change.
A person with cancer at a young age may speak with his or her oncologist about these details. The doctor might refer the patient for genetic counselling or testing if the type of cancer and family history indicate.
If family members are healthy but concerned that they may be at risk, discussion with a health care professional can assist in deciding if genetic evaluation is needed.
Knowing about risk can empower you
Young cancer leaves families feeling like they don’t know what to expect. While genetic information isn’t a complete picture, for some families, it can be an important part of the picture.
The aim of genetic testing isn’t to cause anxiety or to place a family into a high risk category. The aim is to identify individuals who might benefit from informed surveillance, prevention and personalized medical care.
In the end, however, a diagnosis of cancer at a young age does not necessarily mean that cancer is inherited. However, if a diagnosis is made at a very young age or there is a strong family history of cancer, it may be worthwhile to consider having genetics discussed.
That conversation for families can be the first step to replacing uncertainty with knowledge, and, when appropriate, taking action earlier.
