Understanding glioblastoma and its impact on health

Glioblastoma, commonly known as glioblastoma multiforme, is the most aggressive and fatal type of primary brain tumor in adults. Glioblastoma, which is characterized by fast growth and resistance to therapy, has a substantial influence not only on brain function but also on overall health and quality of life.

What is Glioblastoma?

Glioblastoma is a cancer that begins as a proliferation of cells in the brain or spinal cord. It grows swiftly and can invade and destroy healthy tissue. Glioblastoma develops from astrocytes, which support nerve cells.

Glioblastoma can occur at any age. However, older persons are more likely to experience this. Glioblastoma symptoms may include worsening headaches, nausea and vomiting, impaired or double vision, difficulty speaking, altered sense of touch, and seizures. There may also be issues with balance, coordination, and moving portions of the face or body.

Glioblastoma multiforme histology shows a very heterogeneous tumor of necrotic tissue, aberrant blood vessels, and several types of glial cells. Glioblastoma is very difficult to treat due to its complicated cellular structure. It starts from astrocytes—glial cells that support neurons—and is categorized as a Grade IV glioma, the most severe.

There is no cure for glioblastoma. Treatments may halt cancer growth and alleviate symptoms.

Identifying Glioblastoma Symptoms

Early detection is challenging due to the tumor's deep brain location and the ambiguity of the symptoms. The most prevalent glioblastoma symptoms are:

• A headache, especially one that is worse in the morning.
• Nausea and vomiting.
• Confusion or a decrease in brain function, such as difficulties comprehending and interpreting information.
• Memory loss.
• Personality alterations or irritation.
• Vision alterations include impaired vision, double vision, and loss of peripheral vision.
• Speech problems.
• Trouble with balance and coordination.
• Muscle weakness in the face, arms, and legs.
• Reduced tactile sensation.
• Seizures, particularly in someone who has never had them before.

Investigating Glioblastoma Causes

While the causes of glioblastoma are not fully known, risk factors include:

• Genetic mutations (for example, EGFR, IDH1, and TP53)
• Older age, especially between 45 and 70.
• Previous radiation exposure to the head.
• Weakened immune system, either due to illness or medicine.

According to current research, most instances occur spontaneously and are not genetic.

Risk factors due to Glioblastoma:

• Ionizing radiation is a known environmental component that raises the incidence of glioma, particularly after therapeutic radiation treatments.
• Inherited genetic illnesses such as neurofibromatosis types 1 and 2, Li-Fraumeni syndrome, tuberous sclerosis, Turcot syndrome, and retinoblastoma can increase the risk of glioblastoma, but hereditary cases account for less than 1%
• Age is a significant risk factor, with glioblastoma most usually diagnosed in those aged 45 to 70, and the average age of onset is 64.
• Vinyl chloride, a chemical used in plastics and industrial materials, has been tentatively linked to glioma development.
• Pesticide use in agricultural contexts may raise risk, although evidence is inconsistent.
• Working in petroleum refining or synthetic rubber manufacturing may increase your exposure to possibly carcinogenic compounds.
• Smoking and tobacco-related chemical exposure have minor links with glioma, although no definitive causal link has been shown.

Diagnosis and tests suggested for Glioblastoma

How do doctors diagnose glioblastoma?

A healthcare provider will assess your symptoms and do a neurological examination. If it is suspected to have a brain tumor, then the following tests:

• An MRI or CT scan to detect brain tumors
• A biopsy is performed to get a sample of a tumor and analyze the tissue for cancer cells.

What are the different grades of glioblastoma?

To describe brain tumor activity, healthcare clinicians employ a grade system ranging from I (1) to IV (4). Grade I brain tumors develop slowly and are the least aggressive. Grade IV cancers spread quickly and are more aggressive. Glioblastoma tumors are grade IV.

Management & Treatment for Glioblastoma

How are glioblastomas treated?

Tumor removal surgery (craniotomy), radiation therapy, and chemotherapy are all options for treatment. If surgery is not a safe option, the doctor may recommend radiation and chemotherapy to help control the tumor.

Glioblastoma Treatment Options:

While there is no cure for glioblastoma, several treatment options aim to increase survival, alleviate symptoms, and enhance quality of life. These include surgery, radiation, chemotherapy, and developing therapeutics.

1. Radiation therapy: High-energy X-rays are used to harm and eliminate cancer cells. Patients often have up to 30 treatments over six weeks, depending on the size and location of the tumor.
2. Intensity-modulated radiation therapy (IMRT): A more advanced type of radiation that accurately targets the tumor while reducing exposure to nearby healthy brain tissue.
3. Stereotactic Radiosurgery (Gamma Knife): Delivers highly focused radiation beams to the tumor in a single or few sessions, commonly utilized for glioblastoma recurrence following regular radiation treatment.
4. Laser-Interstitial Thermal Therapy (LITT): A minimally invasive therapy that uses laser energy to burn and kill tumor tissue, usually guided by real-time MRI.
5. Targeted therapy: Blocks specific molecular alterations that promote tumor growth, providing a more tailored approach than standard chemotherapy.
6. Tumor Treatment Fields (TTF): Delivers low-intensity electric fields through scalp electrodes to inhibit cancer cell division. TTF is frequently utilized following chemoradiation in suitable patients.

Glioblastoma Chemotherapy and Targeted Therapy.

Glioblastoma chemotherapy, primarily temozolomide, is given orally during and after radiotherapy. Its efficacy varies according to tumor genetics.

Other alternatives for chemotherapy for glioblastoma are:

• Lomustine (CCNU)
• Bevacizumab (Anti-Angiogenic Agent)
• Clinical trials involving targeted agents

These treatments may provide additional survival benefits for some individuals.

Immunotherapy Glioblastoma: It is a Hope on the Horizon.

Despite modest results, immunotherapy glioblastoma research is progressing. Immunotherapies like checkpoint inhibitors and CAR T-cell treatment seek to improve the immune system's ability to detect and fight cancer cells. However, the tumor's immunosuppressive environment remains a significant barrier.

Cystic glioblastoma: A Unique Subtype

A proportion of patients develop cystic glioblastoma, which is characterized by the formation of fluid-filled sacs (cysts) within the tumor. Despite their rarity, these cysts can modify imaging features and have a minor impact on prognoses. Treatment approaches remain mostly unchanged.

Glioblastoma Prevention:

While glioblastoma cannot be avoided entirely, specific measures may help minimize risk and promote brain health:

• Ionizing radiation is a known danger factor for the head; thus, limit exposure to it unless medically essential.
• Avoid using dangerous chemicals, including vinyl chloride, insecticides, petroleum products, and synthetic rubber, especially in work environments.
• Follow workplace safety standards to reduce carcinogenic exposure in high-risk industries.
• Maintain a healthy lifestyle with a balanced diet, frequent exercise, and no smoking to help your immune and cognitive function.
• You should be aware of the hereditary risks if there is a family history of neurofibromatosis or Li-Fraumeni syndrome.
• Use hands-free devices whenever possible, as there is no direct link between cell phone use and glioblastoma.

If brain tumors run in your biological family, you may want to consider genetic testing. Talk to a doctor or a genetic counselor about the risks and benefits of genetic testing.

Glioblastoma Life Expectancy:

Unfortunately, the survival rate for glioblastoma is still low. Key statistics include:

• Median survival time: 12-15 months.
• Two-year survival rate: approximately 25%.
• Five-year survival rate: around 5-7%.

A genetic marker called MGMT (Methyl Guanine Methyl Transferase) methylation can be a positive prognostic factor, with tumors exhibiting this marker having better survival rates. Patients with MGMT promoter methylation, younger age, and complete surgical resection may live longer than the average. 

Living and coping with glioblastoma:

In addition to physical symptoms, glioblastoma has an impact on mental health, mobility, and independence. Patients and caregivers have emotional, logistical, and financial difficulties. Rehabilitation, palliative care, and psychological support are all necessary components of comprehensive care.

References: 

National Library of Medicine - https://pmc.ncbi.nlm.nih.gov/articles/PMC5123811/

National Brain Tumor Society - https://braintumor.org/events/glioblastoma-awareness-day/about-glioblastoma/