Why is Biomarker Testing So Important?
- For patients with glioma, genetic tests like next-generation sequencing (NGS) can reveal key mutations that help doctors determine the best treatment to recommend and help predict the tumor’s behavior.
- A mutation in an enzyme known as IDH is a critical biomarker in gliomas.
- If present, it often opens up specific treatment options and can significantly influence how doctors manage and treat the tumor.
- Certain mutations may qualify patients for innovative “basket trials,” where experimental drugs target the specific mutation rather than the tumor’s location, potentially expanding treatment possibilities.
That said, one concept that’s especially important when it comes to treating glioma these days is “biomarkers.” In simple terms, biomarkers are clues — found in a tumor’s DNA or other parts of its cells — that help doctors understand how a cancer behaves and which treatments might work best.
Read MoreHow Do You Test for Biomarkers?
With the advancement of cancer research, a number of biomarkers have been found that might affect how glioma behaves, and ultimately, which treatments might work best for each patient.“The way to discover that [biomarker] is to do testing,” Dr. Peereboom explains. “The most helpful testing is called Next Generation Sequencing. What that does is it looks at all the DNA in the tumor, and the DNA is analyzed, and there are parts of DNA that may be abnormal or mutated.”
This testing might be performed using tissue obtained during a biopsy or surgery or a blood test.
“There are a handful of those mutations that are called driver mutations,” Dr. Peereboom adds. “Driver mutations, as the name implies, are mutations that actually drive the behavior of the cancer. And for a handful of those, they’re actually, nowadays there are some drugs that will target those mutations.”
IDH: A Key Biomarker in Glioma
One of the most important biomarkers doctors look for is an IDH mutation. This stands for isocitrate dehydrogenase — it’s an enzyme found in cells. When it’s changed (or mutated), it can affect how the tumor grows.
“Some of the well-known mutations, particularly in the lower grade gliomas are called IDH. So, IDH is an enzyme. It is important in the growth, particularly of low grade gliomas. So, that’s something that’s absolutely critical to know for a given tumor because it changes how we will manage, how we’ll take care of such patients,” Dr. Peereboom explains.
In other words, if your glioma has this specific change in IDH, your doctor may recommend certain therapies that directly target this mutation. By addressing the tumor’s unique genetic makeup, the outcome for patients can be significantly improved.
“Essentially, a hundred percent of the time we will send the tumor tissue for next-generation sequencing because that can expand the treatment options,” Dr. Peereboom explains. “It can tell us about the behavior so that we can talk to our patients in a more helpful manner so that they know what might be ahead and what treatment options they have.”
Sometimes, Dr. Peereboom points out, testing for these markers and getting feedback enables patients to enroll in clinical trials that are testing new drugs that haven’t made it through the approval process yet.
“Next-generation sequencing is really important to expand those options for our patients,” he explains.
Questions to Ask Your Doctor
- Do I need any specific biomarker tests, like IDH testing?
- How might the presence (or absence) of certain mutations change my treatment plan?
- Are there targeted therapies or clinical trials that might help someone with my tumor’s biomarkers?
- What are the potential side effects of treatments recommended for my tumor’s specific biomarkers?
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