When a child has cancer, parents often hear unfamiliar terms while doctors discuss tests and treatment. Genomic testing is one of them. It looks at the genetic changes found in cancer cells and gives doctors more information about the disease. In some cases, these results help doctors choose a treatment that matches the cancer's specific genetic features.
What is genomic testing?
Genomic testing looks at the DNA of cancer cells to identify genetic changes, also known as mutations or alterations. Some of these changes make cancer cells grow and survive. Doctors perform the test on a sample of tumour or cancer tissue. They may test a few specific genes or analyze all the genes, depending on the type of test. Genomic testing is not genetic testing. Genomic testing looks at the changes in cancer cells.
What is the purpose of genomic testing?
Not all children with cancer receive the same genomic tests. The decision will be based on the type of cancer and the information that the medical team requires.
The outcomes can be used to assist doctors:
Identify mutations associated with the cancer
Clarify some cancer diagnoses
Determine targets for specific medicines
Find clinical trials that match the cancer
Guide treatment in case of recurrence
These findings can impact the treatment plan for certain childhood cancers. In other situations, the results give extra information but don't alter the treatment plan.
Is the cancer passed on through the genes?
No. If a child has a change in their genes in a tumour, this does not necessarily mean that the child inherited the change from their parents. As cancer cells grow, they may change their genes. These are known as somatic changes and typically only occur in the cancer cells.
If the child's age, type of cancer, family history, or other factors indicate that the child's cancer may have an inherited cause, doctors might suggest separate genetic testing. A genetic counselor can explain what the results mean and help determine whether other family members should consider genetic testing.
What is the method for doing the test?
Doctors need a cancer sample for genomic testing. They may collect tissue through a biopsy or surgery. Depending on the test, doctors may also use a blood sample. The laboratory then analyzes the sample's DNA for specific genetic changes. Testing may take varying lengths of time depending on the test.
What do the results tell you?
The results do not necessarily indicate a treatment target. A report may display:
A genetic modification associated with a potential therapy
A change that does not appear to have a significant effect.
No significant genetic changes have been found.
If there is no treatment target, this does not imply that there are no treatment options. The type of cancer, stage, location, prior treatment, and the child's health are also taken into account.
What Parents Should Ask?
If parents have been recommended to have genomic testing, they can ask:
What does the test look for?
What is the purpose of it for my child?
Would the outcomes alter treatment?
Testing whether it is cancer or inherited genes?
When will the results be available?
Who is going to tell us about them?
Genomic testing provides doctors with more information about a child's cancer and can sometimes help direct treatment. If your child's doctor suggests it, ask them what they hope to find out from the test and what the results might mean for your child's treatment plan.