1. Getting to Know the Brain
The brain is an amazing and complex organ that controls everything we do, think, and feel. It’s like the command center of our body, managing our actions, emotions, thoughts, and many automatic functions. Here’s a simpler look at how the brain works and what it does.
Main Parts of the Brain:
1) The Cerebrum:
• Divided into the right hemisphere (controls the left side of the body) and the left hemisphere (controls the right side of the body)
• Each hemisphere has several sections: the frontal lobe, temporal lobe, parietal lobe, and occipital lobe.
• Responsible for thinking and storing memory.
2) The Cerebellum:
• Located behind and below the cerebrum.
• control balance and coordination.
3) The Brain Stem:
• Regulates basic bodily functions like heartbeat, breathing, and blood pressure.
• Nerves from the cerebrum pass through the brainstem to the spinal cord.
4) The Meninges
• The meninges are thin tissue layers separating the skull from the brain. The outermost layer next to the skull is called the dura. Beneath the dura is the arachnoid layer. Below the arachnoid is the cerebrospinal fluid (CSF), which bathes the brain and spinal cord.
5) The Pituitary Gland
• The pituitary gland releases various hormones into the bloodstream.
6) Brain Cells
• Neurons: The main type of cell in the brain, with millions present. Neurons have long, thin nerve fibers that allow them to send messages to other parts of the brain and throughout the body via the spinal cord.
• Glial Cells: These cells provide support, nourishment, and protection for neurons. DiNerent types of glial cells include astrocytes, oligodendrocytes, and ependymal cells.
2. What Causes Brain Cancer?
The exact causes of brain cancer are not always clear, but several factors are believed to contribute to its development. Here’s a simplified overview to help you understand the possible causes:
1. Genetic Factors:
• Inherited Genetic Mutations: Some people inherit genes from their parents that increase their risk of brain cancer. These mutations can cause brain cells to grow uncontrollably, leading to cancer.
• Sporadic Genetic Mutations: Mutations can also occur spontaneously during a person’s lifetime, not inherited but caused by random errors in cell division or due to environmental exposures.
2. Environmental Factors
• Radiation Exposure: High doses of ionizing radiation, such as those from radiation therapy for other cancers or from nuclear accidents, can increase the risk of brain cancer.
• Chemical Exposure: Prolonged exposure to certain chemicals, like those used in some industrial workplaces, might increase the risk of brain cancer, although this is less common.
3. Age:
• Brain cancer can develop at any age, but it is more common in children and older adults. Different types of brain tumors are more likely to occur at different ages.
4. Family History:
• Having a family history of brain cancer can slightly increase your risk. If close relatives have had brain cancer, there may be a genetic predisposition.
5. Immune System Disorders:
• Individuals with weakened immune systems, such as those with HIV/AIDS or those who have undergone organ transplants and take immunosuppressive drugs, have an increased risk of developing brain cancer.
7) Unknown Factors:
• In many cases, the cause of brain cancer is not known. It can occur even if you don’t have any of the known risk factors.
Note: Key Points to Remember:
i) Most Brain Cancers are Not Inherited: Although genetics can play a role, the majority of brain cancers do not run in families.
ii) Prevention is Not Always Possible: Unlike some other cancers, there are no definitive lifestyle changes that can prevent brain cancer.
iii) Early Detection is Important: Recognizing symptoms and seeking medical advice early can aid in eNective management and treatment of the condition.
3. Types of Brain Tumors
Brain tumors can be classified into different types based on their location, the type of cells involved, and whether they are cancerous (malignant) or non-cancerous (benign).
1. Primary vs. Secondary Tumors:
• Primary Brain Tumors: These tumors start in the brain. They can be benign (non-cancerous) or malignant (cancerous).
• Secondary Brain Tumors (Metastatic): These tumors start in another part of the body and spread to the brain. They are always malignant.
2. Benign Brain Tumors:
• Meningiomas: These are the most common type of benign brain tumors. They develop from the meninges, the layers of tissue covering the brain and spinal cord. They grow slowly and are often treatable.
• Acoustic Neuromas (Vestibular Schwannomas): These tumors develop on the nerves that control balance and hearing, located near the inner ear. They are typically slow-growing and benign.
• Pituitary Adenomas: These tumors develop in the pituitary gland, which is located at the base of the brain. They are usually benign and can affect hormone levels.
3. Malignant Brain Tumors:
• Gliomas: This is a group of tumors that start in the glial cells, which support nerve cells in the brain. Gliomas can be benign or malignant, and they include:
• Astrocytoma: These tumors can be benign or malignant and vary in how fast they grow. Glioblastomas are a type of astrocytoma that are very aggressive and malignant.
• Oligodendrogliomas: These tumors develop from oligodendrocytes, a type of glial cell, and can be slow-growing or more aggressive.
• Ependymomas: These tumors develop in the ependymal cells lining the ventricles (fluid-filled spaces) in the brain and spinal cord. They can range from benign to malignant.
4. Medulloblastomas: These are the most common malignant brain tumors in children. They start in the lower part of the brain and can spread through the cerebrospinal fluid.
5. Other Types of Brain Tumors:
• Craniopharyngiomas: These are rare, benign tumors that develop near the pituitary gland.
They can affect hormone production and vision.
• Pineal Region Tumors: These tumors develop in or around the pineal gland, a small gland located deep within the brain. They can be benign or malignant.
4. How Common Are Brain Tumors?
Brain tumors are a significant health concern in India.
The GLOBOCAN 2020 data indicated that there were 308,102 new cases of brain and other central nervous system tumors, along with 251,329 deaths resulting from these conditions. The Indian Council of Medical Research’s Hospital Based Cancer Registry data from 2021 reported that brain tumors made up 1.6% of all cancer cases.
The most frequent types of brain tumors in adults are benign meningiomas and gliomas, particularly glioblastoma multiforme. Certain types are quite rare. Brain tumors can develop at any age, with some types, like medulloblastomas, being more prevalent in children, and others more common in adults. Typically, tumors that aNect adults are more likely to occur as people get older. Secondary (metastatic) brain tumors are more common than both benign and malignant primary brain tumors.
5. Symptoms of Brain Tumors
Brain tumors can cause a variety of symptoms depending on their size, location, and rate of growth. Here are some common symptoms explained in an easy-to-understand way:
• Headaches:
– Persistent or Severe: Frequent headaches that don’t go away and are often worse in the morning or during the night.
– Changes in Pattern: Headaches that change in frequency or severity over time.
• Seizures:
– New Onset Seizures: Experiencing seizures for the first time or having more frequent seizures if you’ve had them before.
– Uncontrolled Movements: Involuntary movements, jerking, or twitching of muscles.
• Nausea and Vomiting:
– Unexplained Nausea: Feeling nauseous without a clear reason, often worse in the morning.
– Frequent Vomiting: Vomiting that occurs frequently and is not related to other illnesses.
• Cognitive or Personality Changes:
– Memory Problems: Difficulty remembering things, confusion, or inability to concentrate.
– Personality Changes: Noticeable changes in behavior or personality, such as increased irritability or mood swings.
• Vision or Hearing Problems:
– Blurry Vision: Experiencing blurred vision, double vision, or loss of vision in one or both eyes.
– Hearing Loss: DiNiculty hearing or ringing in the ears (tinnitus).
• Balance and Coordination Issues:
– Clumsiness: Trouble walking or performing tasks that require fine motor skills. – Dizziness: Feeling dizzy or unsteady, which can lead to falls.
• Speech Difficulties:
– Slurred Speech: Difficulty speaking clearly or finding the right words.
– Communication Problems: Trouble understanding or expressing language.
• Weakness or Numbness:
– Loss of Sensation: Numbness or weakness in a part of the body, often on one side. – Muscle Weakness: DiNiculty moving or controlling certain muscles.
• Fatigue:
– Constant Tiredness: Feeling unusually tired and lacking energy, even with adequate rest.
• Hormonal Changes:
– Endocrine Issues: Tumors near the pituitary gland can cause hormonal imbalances, leading to various symptoms like changes in menstrual cycles, lactation, or growth issues.
6. Primary vs. Secondary Tumors
The initial location where a tumor begins to develop is known as the primary tumor. Malignant (cancerous) tumors can spread to other areas of the body, forming secondary tumors (metastases). These secondary tumors can grow, invade, and damage nearby tissues, and potentially spread further.
• Primary Malignant Brain Tumors
A primary malignant brain tumor is a type of cancer that originates from cells within the brain. These tumor cells grow and damage the normal brain tissue. Similar to non-cancerous (benign) brain tumors, they can increase the pressure inside the skull. However, unlike most other malignant tumors, primary brain tumors rarely spread (metastasize) to other parts of the body.
There are diNerent types of primary malignant brain tumors, each developing from various cell types in the brain. These tumors are generally graded on a scale from 1 to 4:
– Grade 1 and Grade 2: Low-grade tumors, which tend to grow more slowly.
– Grade 3 and Grade 4: High-grade tumors, which are more aggressive and grow faster.
The higher the grade, the more aggressive the tumor is likely to be. Treatment options and prognosis depend on the type and grade of the tumor.
• Secondary Malignant Brain Tumors
A secondary malignant brain tumor occurs when cancer that began in another part of the body spreads to the brain. Various types of cancer can metastasize to the brain, with the most common being breast, lung, bowel, kidney, and skin (melanoma) cancers.
7. How Brain Tumors Are Diagnosed
Diagnosing a brain tumor involves several steps to accurately identify the presence, type, and location of the tumor. Here’s a simple explanation of how doctors diagnose brain tumors:
• Medical History and Physical Exam:
Medical History: Your doctor will ask about your symptoms, any medical conditions, and family history of illnesses.
Physical Exam: A general physical check-up to assess your overall health.
• Neurological Exam:
Brain and Nerve Function: The doctor will test your reflexes, muscle strength, vision, eye movement, coordination, balance, and cognitive abilities (like memory and problem-solving).
• Imaging Tests:
MRI (Magnetic Resonance Imaging): This is the most common test for diagnosing brain tumors. It uses powerful magnets and radio waves to create detailed images of the brain.
CT scan (Computed Tomography): Uses X-rays to create detailed cross-sectional images of the brain. It’s useful for detecting bleeding and swelling.
PET Scan (Positron Emission Tomography): Shows how the brain and its tissues are functioning, which can help differentiate between tumor types.
Biopsy:
Sample Collection: If imaging tests suggest a tumor, a biopsy may be done. This involves taking a small sample of the tumor tissue.
Surgical Biopsy: Performed during surgery where the tumor or a part of it is removed and tested.
Stereotactic Needle Biopsy: A less invasive method where a needle is used to remove a small sample guided by imaging tests.
Laboratory Tests:
Pathology: The biopsy sample is examined under a microscope by a pathologist to determine the type of tumor and whether it is benign (non-cancerous) or malignant (cancerous).
Molecular Testing: Tests on the tumor cells to identify specific genes, proteins, and other factors unique to the tumor, which can help guide treatment.
Additional Tests:
Lumbar Puncture (Spinal Tap): Sometimes, a sample of cerebrospinal fluid (CSF) is taken from the lower back to check for cancer cells.
Electroencephalogram (EEG): Measures electrical activity in the brain and is used if seizures are a symptom.
What to Expect:
Multiple Tests: Diagnosing a brain tumor often involves several diNerent tests to get a complete picture.
Specialists Involved: You may see a neurologist (specialist in brain and nerve disorders) and a neurosurgeon (specialist in brain surgery) as part of your diagnosis and treatment plan.
8. Treatments for Brain Tumors
Once diagnosed with a brain tumor, the main treatments typically include surgery, chemotherapy, radiotherapy, and medications to manage symptoms like seizures. It’s important to be cared for by a specialist multidisciplinary team experienced in treating brain tumors. In some cases, such as when surgery carries high risks or the tumor is very slow-growing, the initial approach might be ‘active monitoring.’ This involves regularly scheduled scans to monitor the tumor’s growth without immediate surgery or other treatments. The benefits and drawbacks of active monitoring versus treatment will be thoroughly discussed with the patient, and the decision will be made jointly by the patient and doctors. The recommended treatment or combination of treatments depends on several factors, including the type of brain tumor, its grade if it is malignant, its exact location, and the patient’s overall health.
• Surgery:
Surgery is frequently the primary treatment for both non cancerous (benign) brain tumors and primary cancerous (malignant) tumors. The goal of surgery is to remove the tumor, or at least part of it, while minimizing damage to healthy brain tissue. Your specialist will determine if surgery is a viable option for you. However, surgery always carries some risk, as it can potentially harm healthy brain tissue, nerves, or blood vessels.
• Radiation Therapy:
Radiotherapy is a treatment that uses high-energy radiation beams targeted at cancerous tissue to kill cancer cells or prevent them from multiplying. It is sometimes used as an alternative to surgery when operating on a malignant brain tumor is not feasible. Additionally, radiotherapy may be employed after surgery if the entire tumor cannot be removed or to eliminate any remaining cancerous cells following the procedure.
• Chemotherapy
Chemotherapy involves the use of anti-cancer medications to kill cancer cells or prevent them from multiplying. It may be used alongside other treatments like surgery or radiotherapy, depending on factors such as the type of tumor.
• Medication to Control Symptoms
If you experience seizures due to the tumor, anticonvulsant
medications are typically prescribed to manage them. Painkillers may be necessary to alleviate headaches. Steroid medications are also commonly used to reduce inflammation around the brain tumor. This helps lower the pressure inside the skull, which can relieve headaches and other related symptoms.
• Important Points to Remember:
Individualized Treatment Plan: Your treatment plan will be tailored to your specific situation, considering the type and
stage of your brain cancer, and your overall health.
Multidisciplinary Team: Treatment often involves a team of specialists, including neurosurgeons, oncologists, radiologists, and other healthcare professionals.
Side EXects Management: Your healthcare team will help
manage any side eNects of treatment to make you as comfortable as possible.
• Aims of treatment
a) Curative Treatment: Aimed at completely eradicating the cancer, often used for benign tumors or some malignant tumors when cure is possible.
b) Remission: For malignant tumors, doctors prefer this term as it signifies that no evidence of cancer is currently detectable. However, there is a possibility of recurrence later. c) Control: When a cure isn’t feasible, treatment focuses on slowing the progression of the cancer, maintaining quality of life, and managing symptoms.
d) Palliative Treatment: This approach aims to relieve symptoms and improve comfort, often used in advanced stages of cancer.
9. What is the outlook?
It’s challenging to provide a general outlook (prognosis) because each case is unique. For instance, if you have a benign meningioma located in an operable area, the outlook is generally very good. However, for primary malignant brain tumors, the prognosis can vary based on the tumor type, grade, and location in the brain. Secondary (metastatic) malignant brain tumors usually have a less favorable outlook.
Cancer treatment is an evolving field with ongoing advancements, so the information provided here is quite broad. Your specialist, who understands your specific situation, can oNer more precise details about your outlook and how your type and stage of cancer might respond to treatment.