Brain Tumor

A brain tumor is an abnormal growth of cells within the brain or its surrounding structures — arising either from brain tissue itself (primary brain tumor) or from cancer spread from elsewhere in the body (secondary or metastatic brain tumor). Primary brain tumors include more than 120 distinct types classified by cell of origin, WHO grade, and molecular markers. The most common early warning signs of a brain tumor include new-onset headaches (often progressive and worse in the morning), a first-ever seizure in an adult, focal neurological symptoms corresponding to tumor location (arm or leg weakness, speech difficulty, visual changes), or cognitive and personality changes. Because the brain controls all body functions, symptoms depend heavily on where the tumor is located. Any new unexplained neurological symptom — particularly a first seizure in an adult — should prompt urgent brain MRI evaluation. Early imaging is always appropriate; do not wait for symptoms to worsen.

Brain tumors are classified by WHO grade from 1 to 4. WHO Grade 1 tumors (pilocytic astrocytoma, WHO Grade 1 meningioma, ganglioglioma) are considered benign — they grow slowly, have clear borders, and are often curable with surgery alone. WHO Grade 2 tumors are low-grade but infiltrating — they grow into surrounding brain tissue, cannot always be completely removed, and carry a risk of malignant transformation over time. WHO Grade 3 and 4 tumors are malignant — they grow rapidly, are highly infiltrative, and are difficult to control with current treatment. Importantly, even benign brain tumors can be life-threatening depending on their location — a WHO Grade 1 meningioma compressing the brainstem can be more dangerous than a Grade 2 tumor in a non-critical brain region. 'Benign' in brain tumor terminology does not always mean low-risk to the patient.

Glioblastoma (GBM) is the most common and most aggressive primary brain tumor in adults. It is classified as WHO Grade 4 IDH-wildtype glioma. GBM grows rapidly, is diffusely infiltrating (no clear border from normal brain), and is characterized by a high rate of recurrence despite optimal treatment. The current standard treatment for newly diagnosed GBM in patients with good performance status is the Stupp protocol: maximal safe surgical resection, followed by concurrent temozolomide chemotherapy combined with 60 Gy fractionated radiation over 6 weeks, followed by 6 cycles of adjuvant temozolomide. Tumor treating fields (TTFields, the Optune device) worn on the scalp during the adjuvant phase have been shown to improve survival and are now standard of care at many centers. MGMT promoter methylation — present in approximately 40–45% of GBMs — is the most important predictive marker for temozolomide benefit and should be tested in all newly diagnosed GBM patients.

IDH (isocitrate dehydrogenase) mutation status is the most important single molecular marker in adult diffuse glioma. Under the 2021 WHO CNS classification, IDH mutation status defines completely different tumor entities — regardless of how similar they may look under the microscope. IDH-mutant gliomas (Grade 2–4 astrocytoma and oligodendroglioma) have a substantially better prognosis than IDH-wildtype gliomas at any comparable grade, because IDH-mutant tumors generally grow more slowly and respond better to treatment. IDH-wildtype gliomas — unless they meet the criteria for a favorable specific diagnosis — are classified as GBM (Grade 4) by the 2021 WHO system, even if morphologically they appeared lower-grade. IDH-mutant Grade 2 glioma may be treated with vorasidenib (an IDH inhibitor), the first targeted therapy specifically approved for low-grade glioma. A brain tumor report that does not include IDH testing is incomplete and should be reviewed by a specialist neuro-oncology center.

MGMT (O6-methylguanine-DNA methyltransferase) is a DNA repair enzyme. When the MGMT gene is methylated (epigenetically silenced), the enzyme is not produced — leaving brain tumor cells unable to repair the DNA damage caused by temozolomide chemotherapy. MGMT-methylated GBMs are therefore more sensitive to temozolomide and have better overall survival with the standard Stupp protocol than MGMT-unmethylated GBMs. MGMT methylation is present in approximately 40–45% of GBMs. In elderly patients with GBM, MGMT methylation status is particularly important — MGMT-methylated GBM may be treated with temozolomide monotherapy alone (without full radiation), while unmethylated GBM is better managed with radiation alone. Without knowing MGMT methylation status, optimal temozolomide decision-making is not possible. All newly diagnosed GBM patients should have MGMT methylation testing performed on their tumor tissue.

Tumor treating fields (TTFields), marketed as the Optune device, deliver low-intensity alternating electric fields (200 kHz) to the tumor via arrays of transducer patches worn on the shaved scalp. These electric fields disrupt the mitotic spindle — the machinery cells use to divide — causing preferential disruption of rapidly dividing tumor cells while sparing normal non-dividing cells. The Optune device is FDA-approved for newly diagnosed GBM (in combination with adjuvant temozolomide, EF-14 trial demonstrating improved overall and progression-free survival) and for recurrent GBM. Benefit appears greatest with prolonged daily use — approximately 18 hours per day or more. TTFields are non-invasive, do not cause systemic toxicity, and are compatible with concurrent temozolomide. Access varies by country — they are more widely used in the United States than in many other countries. CancerFax can help patients explore TTFields access including at specialist centers in Asia where the device is increasingly available.

Diffuse intrinsic pontine glioma (DIPG) — now classified as Diffuse Midline Glioma H3K27-altered per WHO 2021 — is an aggressive pediatric brainstem tumor characterized by H3K27M or related histone mutations. It arises in the pons (a part of the brainstem controlling basic vital functions), making surgical resection virtually impossible without catastrophic neurological injury. DIPG is one of the most lethal childhood cancers, with median survival approximately 9–11 months with radiation alone (54 Gy fractionated to the brainstem). Conventional chemotherapy has not improved survival in large randomized trials. The landscape changed significantly with ONC201 — a dopamine receptor antagonist that has demonstrated meaningful responses in H3K27M-mutant DIPG/diffuse midline glioma and received FDA accelerated approval (2024) for use after radiotherapy. GD2-targeting CAR-T has also shown remarkable proof-of-concept responses in individual DIPG patients. Clinical trial enrollment at initial diagnosis is a priority recommendation for all newly diagnosed DIPG patients.

A specialist second opinion is particularly important in brain tumors at several points: when the pathology report lacks complete molecular testing (IDH, MGMT, 1p/19q, TERT) for a complete WHO 2021 diagnosis; before initial surgery at a non-specialist center — surgical expertise and intraoperative tools (5-ALA, iMRI, awake craniotomy) affect the extent of safe resection; for a newly diagnosed GBM, to ensure TTFields and clinical trial options are discussed at diagnosis; when BRAF V600E, IDH mutation, or H3K27M mutation is identified — to access vorasidenib, BRAF/MEK inhibitors, or ONC201 respectively; for DIPG in a child — to identify clinical trial access at a specialist pediatric neuro-oncology center; and at first tumor progression, to enroll in a clinical trial before eligibility is compromised by further disease progression. CancerFax can coordinate specialist neuro-oncology second opinions and facilitate access to advanced therapies and clinical trials globally.

The vast majority of primary brain tumors arise sporadically — without an identifiable hereditary cause — and most patients have no affected family members. However, a small proportion of brain tumors occur in the context of hereditary tumor predisposition syndromes. Neurofibromatosis type 1 (NF1) is associated with optic pathway gliomas, astrocytomas, and other CNS tumors. Neurofibromatosis type 2 (NF2) predisposes to meningiomas, ependymomas, and vestibular schwannomas. Li-Fraumeni syndrome (germline TP53 mutation) includes gliomas and medulloblastomas in its cancer spectrum. Gorlin syndrome (PTCH1 mutation) is associated with SHH-activated medulloblastoma. Turcot syndrome links MMR gene mutations (Lynch syndrome) or APC mutations with glioma and medulloblastoma risk. If a patient has multiple family members with brain tumors, or if a brain tumor occurs alongside other unusual cancers in the family, referral for genetic counseling and germline testing is appropriate. For most brain tumor patients, however, no hereditary cause will be identified.

Yes. CancerFax can support brain tumor patients by reviewing MRI reports, biopsy pathology, and molecular profiling results to confirm WHO 2021 integrated diagnosis and identify missing molecular tests; coordinating specialist neuro-oncology, neuropathology, and neurosurgery second opinions at high-volume brain tumor centers; facilitating access to vorasidenib for IDH-mutant Grade 2 glioma, TTFields (Optune) for GBM, ONC201 for H3K27M-mutant DIPG, dabrafenib + trametinib for BRAF V600E-mutant brain tumors, and bevacizumab for recurrent GBM; and helping patients identify clinical trial programs — including investigational CAR-T (EGFRvIII, IL13Rα2, GD2-targeting), targeted molecular therapies, oncolytic virus, and neoantigen vaccine programs — at specialist neuro-oncology centers in China and globally. Contact CancerFax to discuss your specific brain tumor diagnosis, molecular results, and treatment goals.