Learn About Precision Medicine
Understanding genomic testing, molecular diagnosis, and personalized treatment for your child.
Understand the Cancer
What is genomic testing?
Find What Drives It
Why does molecular diagnosis matter?
Treat the Individual
What is personalized treatment?
What is PICK4KIDS?
Bringing molecular testing, expert discussion and precision treatment together for children with cancer.
What is genomic / molecular testing?
Genomic or molecular testing looks closely at the cancer cells to understand what changes are present in the cancer's DNA, genes and other molecular features.
Think of it like looking beyond the name of the cancer to understand how that particular cancer is behaving.
Traditional tests may tell us
“What type of cancer is this?”
Molecular testing can sometimes tell us
“What is driving this cancer, and what makes this cancer different?”
This information may help doctors:
- confirm or refine the diagnosis
- understand how the cancer may behave
- identify changes that can guide treatment
- find opportunities for targeted therapies
- decide whether additional testing or clinical trials may be useful
Important: Molecular testing does not always find a treatment-changing mutation, and it does not replace standard pathology, imaging or other tests. It is an additional piece of information that can help build a more complete picture.
Why does a molecular diagnosis matter?
Two children may have cancers that look similar under the microscope—but their cancers may behave very differently.
The reason may be hidden in the cancer's molecular makeup. For some childhood cancers, identifying a specific molecular alteration can:
Change the diagnosis
Change the risk assessment
Change the treatment approach
For example, a particular genetic change may tell doctors that a cancer belongs to a different biological group, or may suggest that a particular targeted treatment could be considered.
So instead of treating every cancer only according to where it started and what it looks like, modern cancer care increasingly asks:
“What is driving this cancer?”
That is the foundation of precision oncology.
What is personalized treatment?
Personalized treatment means choosing treatment based on the individual child and the biology of their cancer—not using exactly the same approach for every child.
Doctors consider many things:
The child
- age
- overall health
- previous treatments
The cancer
- type and stage
- pathology
- molecular / genomic findings
- response to treatment
The treatment options
- standard chemotherapy
- surgery
- radiation
- targeted therapy
- immunotherapy
- cellular therapy
- clinical trials, when appropriate
The goal is not simply to give more treatment.
The goal is to give the right treatment, to the right child, at the right time—while avoiding unnecessary treatment whenever possible.
A simple PICK4KIDS message
“Molecular testing does not mean that every child will receive a targeted drug. Its value is in giving the treating team more information to make the most informed decision possible.”
Important FAQs for families
Depending on the cancer and the test, testing may require a blood sample, bone marrow sample, or a small piece of the tumour tissue obtained during biopsy or surgery. In some situations, a saliva or buccal (cheek) sample may also be useful. The treating team will recommend the most appropriate sample.
Inherited cancer risk vs testing the cancer itself
Two different questions. Two different tests.
Inherited / Germline Testing
“Is this child genetically predisposed to cancer?”
- Looks at the child's normal DNA
- May have implications for the child and family
- Helps guide cancer-risk assessment and surveillance
Tumour Molecular Testing
“What is driving this cancer?”
- Looks at the cancer's DNA / RNA
- Helps refine diagnosis and identify potential treatment options
- Usually describes changes that are specific to the cancer
| Cancer predisposition / inherited genetics | Cancer molecular / genomic testing | |
|---|---|---|
| Main question | “Why was this child more likely to develop cancer?” | “What is driving this particular cancer?” |
| What is tested? | The child's normal / inherited DNA | The cancer cells / tumour DNA, and sometimes RNA |
| Where does the change come from? | Usually inherited from a parent; occasionally arises very early in development | Usually develops only in the cancer cells |
| Is it present in the whole body? | Yes | Usually no |
| Can it affect family members? | Yes | Usually no |
| Main purpose | Identify inherited cancer risk and guide surveillance / prevention for the child and potentially relatives | Improve diagnosis, understand tumour biology and identify treatments / clinical trials |
| Typical sample | Blood / saliva / cheek cells | Tumour tissue ± blood / normal DNA |
| Example | TP53 variant associated with Li-Fraumeni syndrome | A tumour-specific alteration that identifies a molecular subtype or potential target |
Why should families care about cancer predisposition?
Because sometimes a child's cancer is not just an isolated event. A proportion of children with cancer have an inherited pathogenic variant that increases their susceptibility to cancer. Current NCI information estimates that about 8–10% of childhood cancers overall are associated with an inherited pathogenic variant, although this varies considerably by cancer type.
If an inherited predisposition is identified, it may be important for three reasons:
It may change how we care for the child
The child may need specific surveillance for the original cancer, a second cancer, or other features of the syndrome.
It may influence treatment decisions
Some inherited conditions affect treatment choices, or the way a child responds to certain therapies.
It may provide information for the family
If a pathogenic variant is inherited, parents and siblings—and eventually other relatives—may potentially benefit from appropriate genetic counseling and testing.
An important point for parents
A child having cancer does not automatically mean that the cancer is inherited.
Most childhood cancers are not caused by something a parent did or passed on. Many genetic changes arise during the child's development, or within the cancer itself.
“Some children with cancer have an inherited predisposition. Identifying it when appropriate can help us provide better care for the child and, sometimes, important information for the whole family.”
These two tests can complement each other
Sometimes tumour testing finds a change that could potentially be inherited. That finding may need confirmation with a germline test using blood or another normal tissue sample. Conversely, a negative tumour test does not rule out an inherited cancer predisposition when the child's clinical or family history suggests one.
Tumour testing asks
“What is driving the cancer?”
Germline testing asks
“Is there an inherited reason this child may be prone to cancer?”
Sometimes we need both to understand the complete picture. For PICK4KIDS, precision oncology is not only about finding a drug target—it is also about understanding why the cancer occurred, and what that information means for the child and the family.
Reference: National Cancer Institute (cancer.gov).