Biomarkers can help a treatment team determine the best treatment for a patient, see how the patient is responding, and assist in creating a care plan. New tumor markers are being identified with more frequency, so all tumor markers may not yet be reflected on this list.
With brain tumors, biomarker tests can be used to see if your tumor has certain changes in its genes that may be used to:
- help diagnose the type of tumor you have
- predict how fast your tumor will grow
- suggest how you may respond to certain treatments, such as chemotherapy and, possibly, radiotherapy.
Research is still in early stages and it’s important to know that:
- biomarkers are not treatments
- biomarker tests are only available for certain types of tumors, but research is continually discovering more biomarkers
- biomarkers often don’t give absolute answers, but suggest likely tumor behavior
- not all hospitals offer biomarker tests (although you may be able to be referred to another hospital that does)
- there are advantages and disadvantages to testing.
Advantages
Biomarker test results can be useful in giving more detailed information about your tumor type. This can help to give a more accurate diagnosis and plan appropriate, more personalized treatment.
For certain tumor types, they may also suggest how your tumor may respond to certain treatments and give information that can help estimate your prognosis (likely outcome of your treatment).
The results may also help give an indication as to which clinical trials may be suitable for you. For more information about clinical trials, see our clinical trials web-page and fact sheet.
Ask your healthcare team if testing is done routinely and, if it’s not, think about it carefully and discuss it with them and your family before deciding whether to ask for it.
Things to know about biomarkers for brain tumors:
- None of the predictions from biomarkers are perfect.
- Some tumors will respond differently to what the test predicts.
- Biomarker testing isn’t suitable for everyone with a brain tumor.
- Biomarker tests can only be carried out on a sample of your tumor, either removed during a craniotomy or biopsy operation, and the sample has been analyzed.
- It doesn’t matter how long ago the biopsy was performed, so previous samples can be used, if they’ve been stored appropriately.
- Testing for biomarkers is a relatively new practice, so it’s availability can vary widely, as the time taken to implement the new molecular tests will be different between centers.
Biomarkers for predicting response to treatment and prognosis
1p/19q co-deletion test
Histone H3.3 K27M
IDH1 and IDH2 mutation test
MGMT promoter methylation test
TERT promoter mutation test
Biomarkers used mainly for confirming diagnosis
ATRX and TP53
BRAF
GFRvIII
Whole chromosome markers
YAP1
Research into the molecular structure of brain tumor cells is ongoing and is leading to increased understanding of the role genes play. As a result, other possible biomarkers are of interest.
Many of these other genes and mutations have shown some association with survival and tumor behavior, but many of these tests are very experimental and remain under investigation. As a result, they’re not yet routinely offered as their value in clinical practice has yet to be determined. Other genes and mutations have been associated with survival and tumor behavior. However, many of these remain under investigation and aren’t yet routinely used.