A brain tumor is a collection of neoplasm (abnormal and excessive growth of tissues)
arising in or around the brain. These tumors can disrupt brain function and cause
long-term neurological deficits and even death. Globally, brain tumors make up to
1.8% of all cancer incidences. The International Association of Cancer Registries
(IARC) reported that the incidence of brain tumors ranges from 5 to 10 per 100,000
population in India and ranked brain tumor as the 10th most common type of tumor
About Brain tumor
The brain is one of the most complex organs in the human body. The brain along with
the spinal column makes up the central nervous system (CNS), which controls all the
vital functions of the body.
A brain tumor is a mass of abnormal cells that grow in the brain. These abnormal
cells grow rapidly and invade the healthy areas of the brain. There are different
types of brain tumors; some are benign brain tumors (non-cancerous) and some can be
Brain tumors can either begin in the brain (primary brain tumors) or may migrate from
distant parts of the body to the brain (secondary or metastatic brain tumors).
Signs and Symptoms
The brain tumor symptoms and signs depend on the location and size of the tumor. In
most cases, brain tumors are asymptomatic during the early stage. However, when the
tumor begins to grow and exert pressure on the adjacent brain tissue, the following
symp may be evident:
- Persistent brain tumor headaches that worsen with activity or in the morning
- Nausea and vomiting
- Difficulty concentrating or problem-solving
- Memory changes
- Mood or personality changes
- Weakness on one side of the body
- Impaired speech and language (dysarthria)
- Vision problems
- Loss of balance or coordination
Causes and Risk factors
Though the exact cause of brain tumor is unknown, the primary brain tumor develops
when the normal cells in the brain undergo any mutation (cellular changes) and start
dividing at an uncontrollable rate. The secondary tumor can be the result of cancer
that might have developed in another part of the body and then spread to the brain.
The growth rate, as well as the location of a tumor, determines the severity of the
Factors that might increase the risk of brain tumor include the following:
- Being exposed to ionizing radiations
- Having a family history of brain tumors
- Having a personal history of cancer
- Having a weak immune system
- Being exposed to certain chemicals or carcinogens
- Being exposed to electromagnetic fields
- Being overweight or obese
Diagnostic tests for a brain tumor are recommended when a person experiences the
symptoms that may signal a brain tumor. The symptoms and signs of brain tumor, along
with the medical and family history of the patient are assessed to obtain a complete
The following tests are recommended to confirm the diagnosis:
- Neurological examination: This test involves examining the hearing, balance,
vision, coordination, and reflexes. Abnormal findings in one or more of these
examinations indicate that a specific part of the brain may be affected by a
- Imaging: Imaging tests like magnetic resonance imaging (MRI), computerized
tomography (CT) scan, and positron emission tomography (PET) scan are used to
diagnose brain tumors.
- Biopsy: For the biopsy, a small piece of the tumor is collected through
minimally invasive surgery and is examined in the laboratory to confirm the
diagnosis of the brain tumor and determine whether it is benign or malignant.
- Skull X-Ray: An X-Ray can show the presence of skull cancers secondary to brain
tumors. X-rays can also show the calcium deposits that are found inside some
- Electroencephalography (EEG): This test is used to monitor for possible seizure
activity. In this test, several electrodes are attached to the outside of a
person's head to measure the electrical activity of the brain.
Grading of the Brain Tumor
Brain tumors are graded on a scale developed by the World Health Organization.
Grading classifies tumor cells their features, how they look under the microscope
and how quickly they are dividing.
The grades of brain tumors include:
- Grade I: The tumor cells are nearly identical to healthy cells. They are
slow-growing and unlikely to spread. They can often be treated with surgery.
- Grade II: The tumor cells look slightly different from the healthy
tumors are less likely to grow and spread.
- Grade III: The tumor cells look abnormal and actively divide. They have
potential to transform to grade 4 tumors.
- Grade IV: The tumor cells are actively dividing. In addition, the tumor
both blood vessel growth and areas of dead tissue. These tumors can grow and
spread quickly to other body parts.
The brain tumor treatment aims to remove the tumor as much as possible and prevent
its recurrence. Based on the size and type of the tumor, its growth rate, brain
location, and the general health of the patient, the treatment team may recommend
any or a combination of the following treatment options:
The surgery involves complete or partial removal of tumors surrounding the brain
tissues. It is the first-line brain tumor treatment option for grade-1 tumors.
Even partial removal of tumors near the sensitive areas of the brain may help
reduce the signs of brain tumors and their symptoms.
The possible side-effects of surgery are bleeding, infections at the incision
site, blood clots, etc.
2. Radiation therapy:
This involves delivering high-energy beams to destroy the cancer cells. It is
usually done before the surgery to reduce the size of brain tumors. For brain
tumors, radiation therapy is given either externally by using an external
machine or internally by placing a radioactive substance near the tumor. X-rays,
gamma rays, electron beams, and proton beam therapy are common energy beams used
in radiation therapy. Based on the size, type, and location of the brain tumor,
advanced techniques like Intensity-Modulated Radiotherapy (IMRT), Stereotactic
Radiosurgery (SRS), and Whole-Brain Radiation therapy are used.
Common side effects of radiation therapy include fatigue, headaches, memory
loss, and scalp irritation.
Unlike traditional surgery, this method delivers precise, high-dose radiation
directly to the tumor, which destroys the tumor cells in that area. Various
technologies like the linear accelerator and gamma knife are used in
Chemotherapy is the usage of drugs to destroy rapidly growing cancer cells in
the body. These drugs can interfere with the process of cell division and
promote cancer cell death. Chemo drugs are injected into a vein (IV) or given
orally. Chemotherapy is usually given in cycles and the treatment plan includes
a treatment session and a rest period allowing the body to recover. The most
common drug used to treat brain tumors is temozolomide.
Common side effects of chemotherapy include nausea, vomiting, fatigue, and hair
5. Targeted drug therapy:
It uses specific drugs or other substances to identify and destroy the cancer
cells without harming the healthy cells. Drugs approved for the treatment of
brain tumors are bevacizumab and larotrectinib.
Although there is no way to prevent brain cancers, early diagnosis and proper
treatment may reduce the risk of metastatic brain tumors. Routine screening for
those with a personal and family history of cancer can help in early diagnosis.
Avoiding excessive exposure to radiation and chemicals may also help in reducing the
risk of developing a brain tumor.
The outlook after a brain tumor operation depends on the size, type, and location of
the tumor, and general health. Children with brain tumors need specialized
approaches and care. The survival rate and recurrence rate of cancer vary with the
type and grade of brain cancer and the age of the patient. Follow-up care and eating
healthy, nutritious food can help in faster healing and in preventing possible