There are about 120 different types of brain tumours. Neither all headaches are due to brain tumours, nor all brain tumours are killers. Some are worrisome and some even insignificant. But all are matter of concern and panic to the family.
Origin and types of Brain Tumours
A tumour is a mass or growth of abnormal cells in the body, the nature of which can be a cancer or a non-cancer. The origin of a brain tumour is primarily from the cells of the brain itself or secondarily from the circulating tumour cells in the blood or lymph from the other organs of the body.
The brain tumour is a collection of abnormally multiplying abnormal brain cells either in a controlled or in uncontrolled fashion and also the accumulation of uncontrollably multiplying abnormal non-brain cells which travelled from a distant organ of the body.
Thus there are three types of brain tumours arising from the brain tissue and its coverings, first type is controlled growth with a limiting cover called primary benign tumour (non-cancer), these are either worrisome tumours when located in a vital area of the brain or insignificant if located in a non-vital region.
These comprise more than 70% of all brain tumours. The commonest primary benign tumours are meningiomas which comprise of 30% of all brain tumours and others are schwannomas, craniopharyngiomas, pituitary adenomas etc. The second type arises from the uncontrolled multiplication of abnormal brain cells and the cells of its coverings without any limiting capsule, called primary malignant tumour (cancer).
These are the killer tumours. The primary cancerous or malignant tumours of the brain are gliomas (or astrocytomas) of which the highest grade III and IV (glioblastoma multiforme or GBM) account for 50% of all malignant brain tumours and arise from glial/astrocyte cells of brain. The GBMs are the most aggressive cancers of the brain and spreads very quickly in the whole brain.
However, third tumour type called secondary malignant or metastatic tumour (cancerous) arises from the uncontrolled and unlimited multiplication of non-brain abnormal cells. These arise from abnormal cells (Cancer cells) travelling from other distant organs like lung, breast, stomach, gut, liver etc. and may surely be killer tumours. About 120 types of brain tumours have been differentiated.
What is the Brain Like?
To know why brain tumours cause stupor, coma or paralysis in patients, let us know about the brain? The brain occupies the bony head-box or the cranial cavity without any windows or doors, where it is surrounded all over by the free flowing brain water (CSF) in which it floats. It has two thin and delicate coverings pia and arachnoid and one thick and tough covering called dura.
The brain tissue is like pinkish-white semi-solid jelly incorporated by large and small blood vessels which flow into it through the neck. The brain has upper storey called cerebrum and a lower backyard called cerebellum with brain-stem. The brain-stem is to the brain, like a stem is to the cauliflower and it connects brain to the spinal cord. The surface of the brain is folded with multiple short, long, thin, narrow and broad foldings creating crests and troughs exactly like the surface of a wall-nut kernel called gyrii and sulcii respectively.
The foldings are only to adjust the large surface area of the cortical brain on a proportionately small white matter globe in the cranial cavity. Each half of brain has many lobes of different names like frontal, temporal, parietal etc. and comprise of many cell types (neurons and glial) in structure and function with long tails called axons. The brain extends itself into three main corridors, one into the back bone through the neck called spinal cord and the other two into the eyes called optic nerves.
The brain tissue thrives mainly on the oxygen and glucose in the blood flowing inside it, thus the blood supply to brain is essentially and optimally richer and proportionately better than most of other organs of the body.
The brain does not tolerate any kind of increase in pressure on itself from inside or outside which jeopardizes its blood supply. The pressures on the brain arise from accumulation of brain water, increases in volume of brain tissue or hemorrhages.
The increase in any of the above elements will cause brain compression, that leads to the cessation of numerous functions of the brain, foremost of which is consciousness, the loss of which is called coma and this usually precedes the death.
The brain tumours are the most important causes of the brain compression and cause disabilities of various types from loss of power of special senses to the paralysis of limbs and coma before death.
Causes of Brain tumours
There are many causes for developing a brain tumour in an individual for example radiations (excessive X-Rays), Viruses, chemical compounds, genetic predisposition in families (uncommon), even trauma and also research on other much debatable causes like use of mobile phones and exposure to the magnetic fields is underway.
No one has control on the radiation and viral entries into the body. The chemical pollution has already erupted through the intake norms of processed food on many names like re-fined.
The chemical environment is also created by sprays of pesticides (toxic chemicals) which are inhaled and ingested, since the Valley of Kashmir has vast lands of different fruit orchards which need multiple chemical sprays annually to increase the yield.
Thus there are enough causes and factors in the space to cause cellular mutation in the brain of an individual if the milieu for the cell is timed to react. Several studies related to the brain tumours in the Valley of Kashmir have been reported.
Risk Factors for Brain tumours
A study on brain tumours in Kashmir published in 2008 at Sher-i-Kashmir Institute of Medical Sciences (SKIMS) pointed out that the exposure to pesticides may be the probable cause for the neurotoxicity and stimulation of brain cancers in Kashmir. It also revealed that the primary malignant brain tumours (gliomas) in Kashmir are on a rise since 1999, especially among the elderly population.
This study also showed that glioblastoma multiforme – GBM (the highest grade of glioma) among people of Kashmir accounted for 69.4% of all gliomas. Another study, published in 2010 in an Indian Journal of Oncology revealed direct link of suspicion between brain cancers and pesticide use in orchards and vegetable farms of Kashmir.
This study noted that the brain cancers in pesticide workers were high grade, more virulent and 12% more fatal than the gliomas in non-orchard farmers or non-pesticide exposed individuals. This study also reported familial gliomas in the Valley of Kashmir by recording malignant brain tumours in siblings of many families.
An International study published in 2014 on the ‘brain tumours in Kashmir’ showed that the most common brain tumour type in Kashmir was glioma with its highest grades i.e., grade-III (anaplastic astrocytoma) and grade-IV (glioblastoma multiforme – GBM). These were mostly found in men with a male/female ratio of 2;1 and in an age group of 41-50 years. The next common was a primary benign tumour called meningiomas, mostly in women.
This study reported, presuming population of Kashmir Valley at 7 million, an incidence of 180 to 220 brain cancers occurring every year which means about 2.5 to 3.1 glioma patients/one lakh population/one years in the Valley.
A study of USA shows that the brain cancer comprises only 2% of all cancers but is notoriously difficult to treat. About 55% of brain cancers occurred in males compared to 45% in females, between 2008 and 2012 in the United States.
While as only 36% of benign brain tumours occurred in males compared to 64% in females during the same period in the United States. Almost similar findings have been revealed in the various SKIMS studies.
Management
The symptoms and signs of a brain tumour in patients may be usually headache, vomiting, convulsions, paralysis, loss of vision, speech and hearing, loss of control on the bowel and bladder, loss of consciousness etc. Any of these symptoms may occur together or separately any time. However the tumour may be totally silent, without any symptom or sign, and might have been diagnosed just incidentally.
The diagnosis is usually dependant on the history and clinical examination. But the imaging diagnosis nowadays is very swift anywhere from the first to third World countries, owing to the advanced medical technology.
However, while the complete treatment of benign brain tumours is absolutely or relatively possible with total or lesser recovery, the treatment and prognosis of gliomas (brain cancer) is still unsatisfactory and grim, even in the developed countries, due its unnoticing silent spread and infiltration along the minutest canals of the inner brain which is the reason for the severe disabilities and high mortality.
The standard and complete treatment regimen of the gliomas consists of taking life saving drugs, surgical decompression (removal), radiation and chemotherapy over months.
The planned microscopic and ultrasound guided surgical/operative removal of the tumour has the advantages of reducing the tumour burden/load of the brain thereby relieving the symptoms/signs of the patient and securing the tissue diagnosis to establish the type of glioma which helps in choosing the type of adjuvant (radiation/chemo) therapy.
But the removal of sub-microscopic or nano tumour infiltrations of gliomas extending far into the normal brain tissue like filiform worms can never be achieved by the presently available diagnostic tractography and micro-instruments anywhere in the East or the West. These tumour extensions are taken care by the adjuvant therapies.
The future trends might involve sub-microscopic nano-instruments, robotics and nano-surgical manoeuvres to remove such nano infiltrations hopefully. Almost all the malignant brain tumours need radiation or/and chemotherapy postoperatively.
The tumour might reappear and recur many times with complications even after receiving a standard and full treatment regimen. The life span of a patient with malignant brain tumour without any treatment is naturally very short like 3 to 4 months but with complete treatment regimen, this might improve from months to years. However more important is the quality of the life with the span.
Conclusion
The outcome of the brain tumours depends mainly upon the age of the patient, type and grade of the malignancy and location of tumour inside the brain.
The eventual fate of a high grade glioma or GBM patient, which accounts for only 15% and less of all brain tumours (benign and malignant together), is either the recurrence or severe disability before death or uncomplicated death.
However all brain tumours which are not gliomas, which account for more than 70% of all brain tumours, have a good outcome after complete treatment regimen.
Dr. Abdul Rashid Bhat, Professor & Unit-Head, Department of Neurosurgery, SKIMS, Srinagar.
Disclaimer: The views and opinions expressed in this article are the personal opinions of the author. The facts, analysis, assumptions and perspective appearing in the article do not reflect the views of GK.