GBM: Glioblastoma Multiforme

GBM-Glioblastoma Multiforme

Glioblastoma Multiforme(GBM) is a rare but highly aggressive tumour occurring in the brain. GBM is the most common malignant or cancerous lesion of the brain. It invades the adjoining brain areas very fast but does not spread to other parts of the body.

Glioblastoma Multiforme or GBM is a devastating tumour. It is a WHO grade 4 tumour. WHO classifies brain tumours from grade 1 to grade 4. The grade 4 tumours are the most aggressive and feared tumours of brain. Despite all the advances in modern medicine, the survival from these tumours is very poor.

GBM is not a very common tumour. It affects 5-10 persons per 100000 population. However, the occurrence is increasing over time. It most commonly affects adults, and is more common in males as compared to females. The commonest age group affected is 50-60 years.

The tumour cells of GBM grow very aggressively. As per one study, the median growth rate of these tumours was 1.4% per day. The study found the volume doubling time was just 49.6 days. Hence you can see, why this tumour is so feared. It grows so rapidly and gives no time. As the tumour grows, it acquires new blood supply. Sometimes the acquisition of blood supply is not sufficient to completely sustain the tumour. The central part of tumour may become dead due to lack of supply and is called central necrosis.

Causes of Glioblastoma Multiforme

Despite years of research, no definite causes have been found for this aggressive tumour. Of all the possible causative factors identified, only high dose ionising radiation has been the only confirmed risk factor. History of previous radiotherapy for some other cancer can lead to this brain tumour. People from Hiroshima and Nagasaki showed higher occurrence of GBM.

Despite all the hue and cry about cellphone and electro-magnetic radiation, no conclusive evidence has been found linking to brain tumours.

Symptoms of Glioblastoma Multiforme

Because of the rapid growth rate, these tumours present very fast. The symptoms may be present from a couple of weeks to a few months only. Rapidly worsening headaches, new onset headaches, seizures, weakness in arms or legs, impairment in memory or speech difficulty are quite common symptoms. The type of symptoms depends on the location of the tumour in the brain. As an example, the tumours of temporal lobe of brain present with rapidly worsening memory problems.

Read more about symptoms of brain tumours.

Diagnosing GBM

The doctor would like to order MRI of brain with contrast. The tumour usually takes up the contrast material injected through a vein and it shines brightly on the MRI. There are certain features which are seen commonly in cases of GBM like necrosis in the central part of tumours, ill demarcated outline, and edema in the surrounding brain.

Certain special type of MRI may be ordered in case the tumour is seen close to a potentially important area of brain. This is to help the surgeon plan his surgical approach. As and example, functional mapping of language areas is done using special techniques in case the tumour is seen to be in close proximity to the language areas of brain.

Treatment of GBM

GBM is an aggressive tumour and needs to managed aggressively. The treatment involves multiple modalities. Surgery remains the foremost line of treatment.

Technical advances in surgery, radiotherapy, and chemotherapy have shown
gradual improvements in survival and quality of life of the Glioblastoma patients. However, despite everything the survival period is still depressing.

Surgery for GBM-Maximal safe resection

Surgery aims to remove as much tumour as possible without damaging the normal brain tissues. This reduces the incidence of new neurological problems. The idea is to maintain good quality of life of the patient and increasing the tumour resection. The tumours arising in the frontal lobes have a wider safer resection area.

In areas of important functions, it may not be possible to remove tumour completely. Damage to adjacent important areas may lead to unacceptable problems in the lifestyle of the patient.

Radiotherapy for Glioblastoma Multiforme

Radiation forms an important component of GBM management. It helps in controlling or delaying recurrence by destroying the tumour cells remaining after surgery. Radiotherapy can be given alongside Chemotherapy which enhances their individual effect.

Chemotherapy for Glioblastoma Multiforme

Chemotherapy helps in prolonging survival when combined with surgery and radiotherapy. Temozolamide or TMZ is the most commonly prescribed chemotherapy for GBM. It is given in an oral form and is quite well tolerated.

Prognosis of Glioblastoma Multiforme

GBM is a very aggressive disease. No treatment can CURE the disease. It has very poor survival figures even with the multiple treatment modalities. Prognosis or survival depends on multiple factors like location of tumour, age, previous health status and extent of surgical resection.

Survival beyond the first year is seen in less than 50% of patients after diagnosis. Looking at this figure, it is not hard to ascertain that 5 year survival is a fairytale. These figures take into account all the possible available treatment modalities.

However a lot of clinical research is going on and we may soon find an answer to this.

Disclaimer- This is for the general awareness of the patients and cannot replace expert medical advice. Treatment of neck pain is decided by a clinician after necessary clinical examination and relevant investigations.

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References

  1. Glioblastoma Multiforme: A Review of its Epidemiology and
    Pathogenesis through Clinical Presentation and Treatment
  2. Indian data on central nervous tumors: A summary of published work
  3. Growth dynamics of untreated glioblastomas in vivo

Published by DR. HARNARAYAN SINGH

I am a Neurosurgeon and spine surgeon practising in Gurugram, India. Besides Neurosurgery, I love to read, travel and play tennis.

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