Brain tumors

Brain tumors are classified according to their origin (primary or secondary), their cellular nature (glial or non-glial), and whether they are benign or malignant. Around 100 types of brain tumors have been identified.
Primary tumors originate in the cells of the brain or spinal cord. They are further divided into glial and non-glial tumors. Glial tumors originate in glial cells, which surround and support neurons. Non-glial tumors, on the other hand, develop in brain structures such as nerves, blood vessels, or glands.
Among the tumors that are often benign are:

Although these tumors are not cancerous, they can cause symptoms due to compression.
Malignant tumors include gliomas, which are divided into different subtypes depending on the cells involved:

• Astrocytomas, which originate from glial cells called astrocytes. Glioblastoma is the most advanced, aggressive, and also the most common form in adults.
• Oligodendrogliomas, which develop from cells that produce myelin.
• Ependymomas, which arise near the cerebral ventricles.
• Medulloblastomas, which are more common in children and located at the base of the skull.

Secondary, or metastatic tumors originate from cancer located elsewhere in the body (lung, breast, skin, etc.) and migrate to the brain via the bloodstream. They are more common than primary tumors

The classification of brain tumors is based on two essential criteria: the cell type that causes the tumor and the tumor grade defined by the World Health Organization (WHO). This approach allows healthcare professionals to better understand the behavior of tumors, assess their aggressiveness, and guide treatment strategies.

• Grade I: benign, slow-growing tumors with cells similar to normal tissue. The prognosis is generally favorable, and surgery may be sufficient.
• Grade II: relatively slow-growing tumors that are not very aggressive but can infiltrate adjacent tissue. They may recur or progress to a higher grade.
• Grade III: malignant tumors with abnormal cells that actively reproduce and infiltrate normal brain tissue. High risk of rapid recurrence, multimodal treatment often required.
• Grade IV: very aggressive, rapidly growing tumors, often necrotic. A typical example is glioblastoma. These tumors require an intensive therapeutic approach

The symptoms of brain tumors vary depending on their location, size, and growth rate. Some tumors remain silent for a long time, especially when they develop in areas of the brain that are not heavily used, while others occur suddenly. In all cases, the symptoms result either from compression of neighboring brain tissue or from direct alteration of the functions performed by the affected area.

General symptoms include persistent headaches, often in the morning or exacerbated by coughing, visual disturbances (blurred vision, double vision, loss of visual field), unexplained nausea or vomiting, and the recent onset of epileptic seizures. Other symptoms may include speech disorders, memory problems, behavioral or personality changes, muscle weakness, balance disorders, and excessive sleepiness.

These symptoms are not specific to brain tumors, but their combination or persistence should prompt a prompt visit to the doctor for a thorough examination.

The origin of brain tumors remains partially unknown. Several hypotheses exist, combining genetic and environmental factors, but no single cause has been identified as responsible in the majority of cases.
Brain cells, like all cells in the body, have DNA that regulates their growth, division, and natural death. A brain tumor can develop when genetic mutations alter these normal functions, promoting uncontrolled proliferation. In the case of malignant tumors, cancer cells invade healthy brain tissue, destroy normal structures, and can spread to other areas of the central nervous system via the cerebrospinal fluid or bloodstream.
These mutations can occur spontaneously or be inherited, although hereditary forms are rare.
Among the environmental factors studied, only exposure to ionizing radiation (such as that used in certain therapies or accidental exposure) has been consistently associated with an increased risk of brain tumors. Other suspected exposures include industrial chemicals, viral infections, certain medications, and electromagnetic fields, but the results remain uncertain and often contradictory.

Although the causes remain unclear, certain factors can increase the likelihood of developing a brain tumor.

Age is a determining factor: some tumors, such as medulloblastomas, occur mainly in children, while others, such as glioblastomas, are more common in adults over the age of 60. Ethnic differences are also observed: gliomas affect white people more often, while meningiomas are more common in black people. Gender also influences incidence, with meningiomas being twice as common in women.

A family history of brain tumors or hereditary genetic syndromes (such as neurofibromatosis, tuberous sclerosis, or Li-Fraumeni syndrome) is also considered a risk factor, although these cases are marginal (5 to 10% of cases).

The diagnosis of a brain tumor is based on a combination of clinical examinations, medical imaging, and, in most cases, a biopsy.

The evaluation usually begins with a complete neurological examination to detect any vision, balance, coordination, memory, or speech disorders. The next step involves medical imaging tests, which are essential for locating and characterizing the mass. MRI (magnetic resonance imaging) is the gold standard test because it provides accurate images of the brain and spinal cord. In some situations, specialized MRIs, such as spectroscopy or functional MRI, may be performed. For patients who cannot undergo an MRI, a CT scan is a reliable alternative.
In some cases, a PET scan (positron emission tomography) may be requested to distinguish between a primary tumor and a metastasis.

Confirmation requires a biopsy. This can be performed during surgical removal or stereotactically (image-guided needle biopsy) if the location of the lesion prevents open surgery. Histopathological analysis of the sample allows the tumor to be classified according to its type and grade, which is essential for determining the appropriate treatment.

The treatment of brain tumors depends on many factors: whether the lesion is benign or malignant, its histological type, location, size, growth rate, and the patient's general condition.
There are three main therapeutic approaches: surgery, radiotherapy (including stereotactic radiosurgery), immunotherapy, and chemotherapy.

Surgical treatment

Surgery is often the first therapeutic step, aiming to remove part or all of the tumor, relieve symptoms, and obtain tissue for analysis. When complete resection is possible without compromising vital functions, it significantly improves the prognosis.
Modern techniques include image-guided surgical navigation, intraoperative neuromonitoring, 5-ALA fluorescence, and awake surgery, particularly for tumors located in areas involved in language or movement.

Radiotherapy and chemotherapy

External radiotherapy uses high-energy rays to destroy tumor cells. It is indicated for inoperable tumors or as a post-surgical adjunct. Precision methods such as 3D conformal radiotherapy, IMRT (intensity modulation) or proton therapy allow the tumor to be targeted more accurately while preserving healthy tissue.

Chemotherapy, often used as an adjunct or concomitant to radiotherapy, is based on cytotoxic agents. Certain molecules can be administered orally, intravenously, intrathecally, or even in the form of wafers implanted locally during surgery. Wafers are small tablets containing a chemotherapeutic drug, which diffuses slowly on contact with the surrounding brain tissue. This method allows chemotherapy to be delivered locally, directly to the tumor site, while reducing the rest of the body's exposure to the side effects of systemic treatments. The wafer dissolves naturally within a few weeks after surgery.

Radiosurgery (stereotactic)

Stereotactic radiosurgery (SRS) is an advanced form of non-invasive radiotherapy that delivers high doses of radiation in one or a few highly localized treatments. It is indicated for small, well-defined tumors that are sometimes inaccessible to surgery, such as certain meningiomas, pituitary adenomas, schwannomas, or single brain metastases.Systems such as the NeuroKnife linear accelerator allow for highly precise treatment, reducing side effects.

Brain tumors can develop in different ways. Some remain dormant for years, while others progress rapidly and require immediate treatment. Even benign tumors can cause damage if they compress essential structures in the brain. The expansion of the mass can lead to intracranial hypertension, causing severe headaches, visual disturbances, or persistent nausea. Damage to specific areas of the brain can also cause permanent neurological deficits, such as partial paralysis, speech disorders, or memory problems.In addition, long-term side effects of treatment (surgical, radiation, or chemotherapy) may include cognitive, hormonal, motor, or sensory disorders. Recurrences, whether localized or diffuse, are not uncommon, particularly for high-grade tumors. Long-term follow-up is therefore essential.

Despite these difficulties, advances in diagnosis and treatment now make it possible to significantly improve the survival and quality of life of many patients.

It is recommended that you consult a doctor as soon as persistent or unexplained symptoms that may indicate brain damage appear. These signs include frequent and unusual headaches, vision problems, seizures, memory or behavioral problems, or loss of coordination or muscle strength.

It is also important to see a specialist if existing symptoms worsen, especially for patients who have already been diagnosed with a brain tumor. Regular medical follow-up is necessary, even after treatment, in order to detect any recurrence or complications at an early stage.

Hôpital de La Tour offers multidisciplinary care for brain tumors, drawing on the expertise of neurosurgeons, oncologists, radiation therapists, neurologists, and radiologists. All cases are discussed at weekly tumor board meetings. Thanks to its state-of-the-art equipment and patient-centered approach, the hospital ensures a smooth care pathway, from detection to post-treatment follow-up.

Is a brain tumor always cancerous?

No. Many brain tumors are benign, but their location can still cause neurological disorders.

What are the warning signs?

Persistent headaches, visual disturbances, memory loss, behavioral changes, or epileptic seizures are reasons to seek medical attention.

Can the tumor be completely removed?

It depends on its size, location, and type. Some can be completely excised, others only partially.

What are the side effects after treatment?

Fatigue, cognitive impairment, memory loss, and sometimes hormonal or motor disorders, depending on the location and treatment.

Can you live a normal life with a brain tumor?

Yes, in some cases. Medical follow-up and appropriate care often make it possible to maintain a good quality of life.

Are brain tumors hereditary?

The majority are not. However, certain rare genetic diseases can predispose individuals to their development.

How is the diagnosis made?

It is based on a clinical examination, brain imaging (MRI, CT scan), and often a biopsy for histological analysis.

Which specialists should be consulted?

A neurologist, neurosurgeon, oncologist, and radiation therapist generally make up the referral team.