Understanding Gliomas and Gene Mutations
- Understanding your tumor’s molecular profile can empower you to make informed decisions about your care and explore potential treatment advances that could improve response to treatment.
- One of the most significant developments in glioma treatment is the discovery of IDH (Isocitrate Dehydrogenase) mutations, which are found in many lower-grade gliomas and some glioblastomas.
- Identifying these mutations has enabled researchers to develop a new therapy option called IDH inhibitors.
- IDH inhibitors aim to slow or stop tumor progression and have shown a lot of promise for specific patients with lower-grade gliomas.
One of the most significant developments in glioma treatment is the discovery of IDH (Isocitrate Dehydrogenase) mutations, which are found in many lower-grade gliomas and some glioblastomas. IDHs are specific genes that produce enzymes that help the cell to produce energy and its mutation potentially disrupts the cell’s normal function. Identifying these mutations is crucial for determining treatment options, including the use of drugs known as IDH inhibitors.
Read MoreWhat is Molecular Testing for Gliomas?
Molecular testing analyzes tumor cells to detect genetic alterations that may influence the course of the disease and the response to therapy. It means that doctors are not only looking for the cell appearance in the microscope, but going much deeper into its molecular characteristics to target regions with possibilities of treatment.For gliomas, testing typically includes the following:
- IDH1 and IDH2 mutation testing: These mutations are present in about 70-80% of lower-grade gliomas and secondary glioblastomas. “It became clear there’s a new mutation, IDH, which is ISO dehydrogenase, 1 or 2,” Dr. Jensen explains. “We found out that having a mutation in that particular gene, having an IDH-1 mutation, was actually a good thing … So, it completely changed the way that we looked at it, and later changed the way the pathologist even diagnosed.”
- 1p/19q Co-deletion testing: Often found in oligodendrogliomas, this genetic feature can guide treatment decisions.
- MGMT Promoter Methylation testing: This determines the tumor’s sensitivity to chemotherapy (temozolomide).
- TERT, ATRX, and TP53 mutations: These provide additional information about tumor classification and prognosis, or response to treatment.
Why is IDH Mutation Testing Important?
Identifying these mutations has enabled researchers to develop new therapies.
“We now have an inhibitor that actually goes in and can target tumors that are IDH-1 mutated — and this class of drugs became FDA approved last year,” Dr. Jensen explains.
Molecular testing is important for a number of reasons, including prognosis, as patients with IDH-mutant gliomas have a better overall response to treatment compared with those with IDH-wildtype tumors, and for treatment personalization.
IDH inhibitors block the abnormal enzyme activity caused by the mutation that promotes tumor growth. By targeting this process, IDH inhibitors aim to slow or stop tumor progression. Several IDH inhibitors are being studied in clinical trials, and some have shown promising results in slowing tumor growth and improving outcomes in patients with IDH-mutant gliomas.
How is Molecular Testing Done?
The process involves analyzing a sample of tumor tissue, usually obtained during surgery or a biopsy.
Pathologists perform specialized tests to detect mutations and other genetic markers. In some cases, a liquid biopsy (a blood test that detects tumor DNA) may be used for additional insights, although it’s value is still being investigated at this point.
Questions To Ask Your Doctor
- Should I undergo molecular testing?
- How would an IDH mutation alter my treatment path?
- Would an IDH mutation change my prognosis?
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