10 Things You Should Know About Glioblastoma (GBM), One of the Most Lethal Brain Cancers

Glioblastoma (GBM) is the most aggressive and lethal form of brain cancer, accounting for approximately 15% of all primary brain tumors. Despite advancements in medical research, GBM remains an incurable disease with limited treatment options and a poor prognosis. Below are ten key facts that highlight the characteristics, risk factors, and current treatment strategies for GBM.

1. GBM is the most aggressive type of glioma – Classified as a Grade IV tumor by the World Health Organization, GBM represents over 60% of primary brain tumors in adults. It is characterized by rapid, uncontrolled cell growth, highly invasive tumor masses, and significant disruption of surrounding brain tissue.

2. Poor Prognosis – Even with surgical resection, radiation therapy, and chemotherapy, GBM remains an incurable disease. The median survival time post-diagnosis is approximately 14–15 months, and the five-year survival rate is below 5%. This is primarily due to GBM’s rapid progression, treatment resistance, and its ability to infiltrate healthy brain tissue.

3. Age and Gender Prevalence – Although GBM can develop at any age, it most commonly affects adults between 55 and 60 years old. Men are more frequently diagnosed than women. Genetic mutations, such as alterations in tumor suppressor genes like TP53, can also contribute to an individual’s risk of developing GBM.

4. Radiation Exposure as a Risk Factor – The only well-established environmental risk factor for GBM is high-dose ionizing radiation. Additionally, rare genetic syndromes such as neurofibromatosis type 1 (NF1) and tuberous sclerosis can predispose individuals to GBM, though most cases occur sporadically with no clear environmental trigger.

5. Primary vs. Secondary GBM – GBM can be classified into two main types: primary GBM, which develops afresh in healthy brain tissue, and secondary GBM, which evolves from pre-existing lower-grade gliomas (e.g., grade II or III astrocytomas) over several years. While secondary GBM tends to have a slightly better prognosis, it remains highly aggressive.

6. Symptoms – GBM symptoms vary depending on tumor location but commonly include cognitive impairment (memory loss, difficulty concentrating), focal neurological deficits (weakness or numbness), seizures, headaches, and personality changes. Symptoms often progress rapidly due to the tumor’s aggressive nature.

7. Diagnosis – MRI is the gold standard for diagnosing GBM, offering high-resolution images that define tumor boundaries. Functional MRI (fMRI) and perfusion-weighted imaging (PWI) provide additional insights into tumor function and blood flow. Although CT scans may be useful in emergency settings, they are less effective in evaluating GBM’s characteristics.

8. Surgical Resection as a Key Treatment – Surgery is the primary treatment option, aiming to remove as much of the tumor as possible. However, complete removal is nearly impossible due to the infiltrative growth of GBM. Technologies like intraoperative MRI and fluorescence-guided surgery help maximize tumor resection, though recurrence remains common within months.

9. Chemotherapy and Emerging Treatments – Temozolomide (TMZ) is the standard chemotherapy treatment for GBM, which works by damaging the DNA of tumor cells. However, resistance to TMZ is a significant challenge, particularly in tumors with high MGMT (O6-methylguanine-DNA methyltransferase) expression, which repairs the DNA damage induced by TMZ. Novel treatment approaches, including immunotherapy and targeted therapy, are being explored to overcome resistance and improve patient outcomes.

10. The role of early detection: Early detection of glioblastoma is critical for improving treatment outcomes. Identifying the tumor early allows for more effective surgery, better symptom management, and earlier intervention with therapies that can slow its progression. Since glioblastoma symptoms, such as headaches and seizures, can be mistaken for other conditions, seeking medical attention for persistent symptoms is essential, as timely diagnosis can help extend survival and maintain quality of life.

Conclusion

Despite extensive research, glioblastoma (GBM) remains one of the most challenging cancers to treat. Advancements in molecular research, personalized medicine, and innovative therapies are essential for improving survival rates and enhancing patients' quality of life. Early detection plays a critical role in this process, as it significantly impacts prognosis and overall patient outcomes.

REFERENCES

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2.      https://www.mdanderson.org/cancer-types/glioblastoma.html

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4.      Kanderi T, Munakomi S, Gupta V. Glioblastoma Multiforme. [Updated 2024 May 6]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK558954/

5.      Verhaak, R. G. et al. Integrated genomic analysis identifies clinically relevant subtypes of glioblastoma characterized by abnormalities in PDGFRA, IDH1, EGFR, and NF1. Cancer Cell 17(1), 98–110 (2010).

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