Glioblastoma

Glioblastoma (GBM) is the most common and malignant tumor among neoplasms of the central nervous system. It originates in glial cells, which are responsible for supporting the cells of the nervous system. It is fast-growing and can manifest at any age, although it is more common in adults. Due to its malignancy, these tumors have a poor prognosis. Its incidence is very low, not exceeding 2-3 cases per 100,000 inhabitants.

The exact causes of glioblastoma are unknown. It can develop from a diffuse astrocytoma or an anaplastic astrocytoma (secondary glioblastomas), but in most cases, it occurs de novo, without any evidence of prior neoplasia.

At present, ionizing radiation is the only unequivocal risk factor identified for glial and meningeal tumors. Studies indicate that cranial radiation, even at low doses, can increase the risk of glial tumors, with a latency period of up to 20 years after exposure.

There are other factors that may contribute to the development of the disease:

• Genetic disorders that predispose individuals to tumor formation, such as neurofibromatosis type 1 and type 2, Lynch syndrome, Turcot syndrome, and Li-Fraumeni syndrome.
• Although it can develop at any time, it is more common after the age of 45.
• Gender, being slightly more common in men than in women.

Because glioblastomas can grow rapidly, the most common symptoms are generally caused by an increase in pressure in the brain. These symptoms may include headaches, nausea, vomiting, and drowsiness. In addition, seizures, progressive cognitive dysfunction, personality changes, behavioral changes, and memory loss may occur.

Depending on the location of the tumor, patients may develop a variety of symptoms such as weakness on one side of the body, memory loss, and/or speech difficulties and visual changes.

There is no complete preventive measure for the development of glioblastomas; however, in some cases, avoiding modifiable risk factors may help reduce it. At present, the only identified risk factor clearly associated with the development of these tumors is exposure to ionizing radiation.

Exposure to this type of radiation can occur through different routes:

• Internal exposure: occurs when the radionuclide is inhaled, ingested, or injected.
• External exposure: occurs when radioactive material is present in the environment.

People most exposed to this type of radiation include astronauts (due to cosmic radiation), X-ray medical staff, researchers, and personnel at radioactive facilities. Additionally, additional exposures can occur with each X-ray examination and nuclear medicine procedure.