The term ‘brain tumour’ can sound frightening, but not all of them are fatal. Some may not even require treatment. Generally, we use the term ‘tumour’ to include both benign and malignant varieties of cellular growth. A malignant tumour is called cancer. Read on more to find out about brain tumour and brain cancer.
What is brain cancer?
Brain cancer consists of two types: primary and secondary. Primary brain cancer means cancer that arises from the brain tissue itself. Secondary brain cancer refers to cancer that travels from other regions of the body to the brain. The process of traveling of cancer cells from one part of the body to another part is called metastasis. E.g., cells of kidney cancer, skin cancer, or breast cancer can travel to the brain through blood and lymph and get deposited there.
Globally, every year 10-17 cases of brain cancer are reported per 100,000 population. According to GLOBOCAN (Global cancer observatory) and a research study, there are about 4 cases of brain cancer per 100,000 population in eastern Asia and about 2 cases per 100,000 population in southeastern Asia.
What are the causes of brain cancer?
It occurs due to mutation in the DNA of a cell which causes its abnormal and uncontrolled growth. A mutation is defined as an alteration of the genetic material of a cell.
What are the risk factors of brain cancer?
- Genetic predisposition
- Family history of brain cancer
- Smoking and drinking
- Viral infection e.g., Epstein-Barr Virus
- Radiation exposure
- Environmental toxins
How to classify brain tumours?
There are different types of cells in your brain e.g. astrocytes, glial cells, ependymal cells, etc. Cancer arising from these various types of cells are named accordingly. Some examples of brain tumour are as follow:
- Astrocytoma: brain tumour that originates from astrocytes.
- Glioma: brain tumour that originates from glial cells.
- Pituitary adenoma: tumour arising from the pituitary gland (a gland located inside the brain that controls the secretion of other hormones).
- Acoustic neuroma: tumour arising from a nerve fibre inside the brain.
- Meningioma: tumour arising from the covering of the brain known as meninges.
What are the symptoms of brain cancer?
Symptoms depend upon the location, rate of growth, and size of a tumour. Since the skull is a closed space, any extra mass inside it raises the pressure inside the brain. Some symptoms of brain cancer include:
- Headache: new onset of headache or change in the pattern of headache if a patient has a preexisting headache. Headache, particularly in the morning, suggests raised pressure inside the brain
- Seizure: abnormal jerky movement of body parts due to unusual electrical discharge inside the brain
- Change in the level of consciousness
- Difficulty in walking
- Hallucination: perception of sensation that is not normally present.
- Nausea and vomiting
- Problems in vision
- Nystagmus: It is an unusual movement of the eye in to and fro direction
- Memory problem
- Change in speech
- Problem in coordination
- Altered sensation to touch
- The weakness of arms or legs
- Change in behaviour and personality
How to diagnose brain cancer?
A doctor takes a detailed history, performs a physical exam, and neurological exam.
Neurological exam: It includes an examination to test the vision, the coordination of the body, muscle strength, and sensation.
MRI or CT brain: The advantage of MRI over CT scan is that it does not expose a patient to radiation and allows clear visualisation of soft tissue. But since CT scan is economical, it is also used sometimes as an alternative to MRI.
Brain biopsy: It involves taking samples of brain tumour tissue and looking under a microscope to determine the origin and nature of cancer.
How to manage brain tumours?
Management of a brain tumour requires a team approach. A team of neurologists, oncologists, neurosurgeons, radiologists, and physical therapists is involved in the care of patients. If cancer is detected in an early stage, treatment helps to slow down the progression and improve the quality of life. These treatments may need to be used in combination depending on the type of tumour.
Surgery can be done if the cancer is located in a surgically accessible location. It improves the symptoms and may prolong the survival of a patient. But the downside is that since it is an invasive procedure, it carries a risk of bleeding and infection.
Chemotherapy means the administration of drugs inside the body in the form of a pill or injection to kill cancer cells. These drugs have a variety of side effects.
Radiotherapy means exposing protons and X-rays to kill cancer cells. It is of two types: external beam radiotherapy (where radiation is exposed from an external machine) and brachytherapy (where a radiation-emitting substance is placed inside the brain).
Radiosurgery involves exposing a concentrated beam of radiation particularly focused on a small area of the brain where the cancer is located. Gamma knife and linear accelerator are used in radiosurgery.
A patient should be rehabilitated after treatment to help return to his normal daily life. Some rehabilitation methods include physical therapy, occupational therapy, speech therapy, etc.
A single sitting of treatment does not cure the problem, instead, a patient may require frequent follow-up.
If a patient has a terminal stage of cancer, high-grade cancer, or if cancer has spread widely inside the body, then patients may require hospice care. Hospice care focuses on improving the suffering and quality of life of patients rather than prolonging survival.
What is the outlook of brain cancer sufferers?
The outlook of treated brain cancer depends on multiple factors: stage of cancer, age of the patient, degree of metastasis, location of the tumour inside the brain (whether it is located in cerebrum, cerebellum, pituitary gland, etc.). Despite instituting all effective treatments, the survival of patients is not that good. Various studies have reported that the survival rate of patients range from less than 5% to 86%.
Article is written in conjunction with World Brain Tumour Day 2021, held on 8 Jun.