Brain Tumours
Introduction
If the cells in the brain grow irregularly it is called brain tumor.
They are of two groups:
Primary brain tumors
Primary brain tumors originate within the brain tissue. Tumors in which growth is slow are called low-grade tumors, where as fast growing tumors are called high-grade tumors. Sometimes low-grade tumors convert into high-grade tumor.
Secondary brain tumors
Secondary brain tumors spread from a primary cancer located in another part of the body e.g.lung, breast. These brain tumors are also called as metastatic cancer or brain metastases.
Types of Primary Brain Tumors
Different types of primary brain tumors are there:
Gliomas
Gliomas are the most common primary brain tumors. These gliomas usually arise from the supporting cells of the neurons in the brain called as glial cells. These gliomas are graded usually ranging from 1 to 4 depending on the growth. These are commonly seen in the middle age and older age people.
The types of gliomas include:
1. Astrocytoma
Astrocytoma is the most usual type of glioma.
✔ Grade I gliomas are benign and are sometimes called as Juvenile pilocytic Astrocytoma. They occur most commonly in children and can be cured with surgery alone.
✔ Grade II gliomas are also called as low-grade gliomas. These are most commonly treated with surgery and sometimes require additional treatment after surgery. Grade 2 gliomas can transform into more aggressive grade 3 or grade 4.
✔ Grade III gliomas are classified as high grade gliomas. It is a cancer tumor.
✔ Grade IV gliomas or glioblastoma are more aggressive brain tumors.
2. Oligodendroglioma
3. Ependymoma
4. Brain stem glioma.
Non-glioma tumors
Tumors that arise from cells other than glial cells are called non-glioma tumors.
Types of non-glioma tumors:
✔ Meningioma:
A tumor that arises from the meninges is called meningioma. It is noncancerous
tumor.
✔ Pineal gland and pituitary gland tumors.
Tumor in the pituitary gland is called pituitary gland tumor.
✔ Primary CNS lymphoma:
Primary central nervous system lymphoma is caused by tumor in the lymph tissue of the brain.
✔ Medulloblastoma:
Medulloblastoma is a type of cancer tumor usually found in children. It starts in the part of the brain called cerebellum.
✔ Craniopharyngioma.
It is a type of brain tumor that originates near pituitary gland.
✔ Schwannoma:
Schwannoma tumor is uncommon and begins in the nervous system.
Risk Factors
The risk of getting brain tumor may increase through the following factors:
1. Age: People of any age can get a brain tumor, and most probably in children.
2. Gender: At large men get brain tumor than women.
3. Home and work exposures: Brain tumor can develop more in people who have close contact with pesticides, oil products, rubber, etc.
4. Family history: 5% of the people may get brain tumor through hereditary factors.
5. Exposure to infections, viruses: Exposure to some infections and viruses have chances to get brain tumor.
6. Electromagnetic fields: Electromagnetic fields have least impact on getting brain tumor.
7. Ionizing radiation: Past treatments to the brain with radiation can cause brain tumor.
8. Head injury and seizures: Research tells that Head injury and seizures may lead to brain tumor to some extent if they are very serious.
9. N-nitroso compounds: Brain tumor is often caused from nitrites or nitrates.
Symptoms and Signs
Symptoms of brain tumor are classified into 2 types, general and specific. General symptoms are because of the tumor in the brain. Specific symptoms occurs when tumor disturbs the working of a particular part of the brain.
General symptoms:
✔ Severe headache
✔ Seizures
✔ Personality changes
✔ Changes in memory
✔ Nausea or vomiting
✔ Fatigue
✔ Drowsiness
✔ Sleep problems
✔ Memory problems
✔ Ability of walking may disturb
Specific symptoms:
✔ Pressure near the tumor.
✔ Loss of balance
✔ Loss of initiative, sluggishness
✔ Muscle weakness or paralysis
✔ Complete or limited loss of vision
✔ Variations in hearing, speech
✔ Memory changes
✔ Problems in understanding
✔ Weakness
✔ Inability to look upward occur in pineal gland tumor.
✔ Difficulty in swallowing
✔ Facial weakness
✔ Changes in vision
Prognostic factors
Depending on many factors like type of the tumor, place of the tumor and grade of the tumor the treatment for the brain tumor is decided.
Factors that decide treatment of brain tumor:
Tumor histology:
Predicting of the growth of the tumor by knowing the type and grade of the tumor is called Tumor histology.
✔ Age:
Younger adults has more options for prognosis.
✔ Symptoms:
Prognosis can be determined by the signs and symptoms the brain tumor patient.
✔ Extent of tumor residual:
Extent of tumor residual refers to the amount of tumor left in the body after surgery.
✔ Tumor location:
Depending on the location of the brain tumor prognosis is determined. Molecular features: Definite genetic mutations which are found in the tumor can help to determine prognosis.
✔ Functional neurologic status:
Better neurologic status of the brain tumor patient can be given better prognosis.
✔ Metastatic spread:
A tumor that spreads to other parts of the body can have lesser prognosis.
✔ Recurrent tumor:
A tumor which comes back after treatment is called recurrent tumor.
Types of Treatment
Treatment options depend on:
✔ The size of the tumor
✔ Grade and type of the tumor
✔ Whether there is pressure on important parts of the brain
✔ Spreading of the tumor
✔ Side effects
✔ The patient’s overall health and preferences
If the tumor can be removed like a low-grade brain tumor surgery can be the only treatment. In case of high-grade tumors surgery is followed by radiation therapy and chemotherapy. Immunotherapy and targeted therapy are other treatment ways. Treatment options of brain tumor:
Physical, social, emotional effects of a brain tumor
People having brain tumor have many symptoms and side effects. Along with these physical effects brain tumor treatment causes some emotional and social problems. Dealing with these effects is called palliative care, which is also called as supportive care. Supportive care is given to the patient by supporting mentally and also physically. Patients with brain tumor can sometimes have severe symptoms, then palliative care helps to lessen symptoms and give them good quality of life to some extent. Family support is also a part of palliative care.
Supportive care includes:
✔ Drugs are used to decrease swelling in the brain, and therefore reduce headache.
✔ Anti-seizure medicines:
These medicines help to control seizures.
Surgery
Surgery is an operation which is the initial treatment for brain tumor. Tumor is removedduring operation. Craniotomy is the process of removing a part of the skull for the treatment,which is covered by the bone of the patient after the removal of the tumor. Through surgery a sample tissue can also be taken for biopsy. The result of the biopsy helps to decide whether to use medications or radiation therapy. In some cases, there will be no possibility for surgery due to the location of the tumor, which are called as inoperable tumors. Many recent advances are made in surgery like enhanced imaging, cortical mapping and fluorescent dyes. Surgery is followed by some other treatments depending on the condition of the brain tumor.
Radiation therapy
Radiation therapy is given to decrease the growth of the tumor or stop the growth. Radiation therapy is given sometimes along with chemotherapy and after surgery. Definite number of treatments are involved in radiation therapy. The following are different ways of radiation therapy:
✔ Conventional radiation therapy:
Conventional radiation therapy uses x-ray films to decide the location of the treatment.
✔ 3-dimensional conformal radiation therapy (3D-CRT):
3-dimensional conformal radiation therapy is used to create 3-dimensional image of a tumor and nearby tissue in a computer. CT scan and MRI scan results are used.
✔ Intensity modulated radiation therapy (IMRT):
Intensity modulated radiation therapy is a type of radiation therapy that targets tumor more directly. It is like 3D-CRT and gives high dose of radiation. It gives less radiation to the nearby healthy tissue
✔ Proton therapy:
Protons are used in the place of x-rays in the proton therapy. Less radiation is required for the treatment of some tumors, then proton therapy is used, which is a type of external-beam radiation therapy.
✔ Stereotactic radiosurgery:
The treatment in which high dose of radiation targeted to the tumor is called Stereotactic radiosurgery. Healthy tissue is not effected in this treatment.
✔ Fractionated stereotactic radiation therapy:
If stereotactic radiosurgery is alienated into small doses and are given daily then it is called as fractionated stereotactic radiation therapy. There are side effects for radiation therapy may be for short period and long period. Short- term side effects radiation therapy may disappear after treatment.
Short-term side effects
✔ fatigue
✔ mild skin reactions
✔ hair loss
✔ upset stomach
✔ neurologic symptoms
Long-term side effects
✔ memory problems
✔ hormonal problems
✔ difficulty in understanding
Therapies using medication
Treatments that uses medication are called systemic therapy. These treatments uses drugs to kill tumor.
Types of medications:
✔ Chemotherapy
✔ Targeted therapy
Chemotherapy
Chemotherapy is used to kill the tumor cells, by stopping their growth and preventing them from multiplying. Drugs are used in chemotherapy. Different types of drugs are used in this process. Some of them are :
✔ Gliadel wafer indicates treating high-grade glioma. It contains the drug called carmustine.
✔ The most common drug used for treating brain tumors is Tammuz Olamide or timid. It is often given over a five-day period, usually first five days of the month. The patient has rest for a month where they don’t take chemotherapy while the drug is working in their system.
✔ Lomustine, procarbazine, and vincristine are combined and used sometimes with
radiation therapy. When the patient is getting active treatment, they are watched through MRI scan for every 2 to 3 months. The grade of the tumor decides the gap between the MRI scans. Most of the side effects of the chemotherapy disappears after the completion of the treatment, such as diarrhoea, fatigue, loss of hair, nausea. Some of the side effects may cause damage to kidney.
Targeted therapy
Specific genes and tissue environment, which support tumors growth, are targeted in the targeted therapy. A variety of targeted therapies are being studied to treat brain tumors that contain other specific molecular changes.
Alternating electric field therapy (tumor treating fields)
Non-invasive movable device is used by alternating electric field therapy. This device restricts spreading and growing of a cancer cell. Electrodes are placed outside of patients head to produce electric field. Patients who are diagnosed with glioblastoma can be treated with alternating electric field therapy. Side effects may include mood changes, headache trouble in sleeping. All patients treated with alternating electric field therapy may not get side effects.
Remission and the chance of recurrence
If the tumor is not found in the body, then it is called remission. Even though there are no signs of tumor growth there are chances to get tumor again in primary brain tumors. A remission can be temporary or permanent, due to which there will be doubt of recurrence to many people. It is better to continue MRI scans frequently even if the tumor growth is stopped. If tumor is found again then tests are made to decide the type of treatment.
Treatment options may include:
✔ Temozolomide
✔ Bevacizumab
✔ Electric field therapy is given for people with recurrent high-grade glioma alternately.
✔ Clinical trials studying new treatments
Metastatic cancer
Metastatic cancer is caused when cancer cells spreads from their starting place to another place. This happens when the tumor with cancer breaks. It is difficult to stop cancer if it started spreading. Treatment is given according to the place where it has spread. Surgery, radiation therapy, immunotherapy, targeted therapy can be included in the treatment of metastatic cancer.
Treatment of brain metastases
Metastatic cancer is also called as secondary brain tumor and brain metastases. Sometimes combination of treatments are included to treat brain metastases. In Metastatic cancer growth is very fast and damages brain tissue which are near to the tumor. Symptoms of the brain metastases include memory loss, seizures and headache.
Types of treatment available are:
✔ Surgery:
Doctor recommends surgery when there is coordination between symptoms and location of the tumor. Surgery removes the tumor as much as possible. Mostly used type of surgery for metastatic cancer is called craniotomy.
✔ Radiation therapy:
X-rays and some other forms of radiation are given for the treatment of brain metastases. Radiation therapy treats multiple tumors. High dose of radiation is given in the stereotactic radiosurgery which targets only the tumor, other healthy tissues are
protected from the radiation exposure. Whole-brain radiation is recommended for some people to treat multiple tumors.
✔ Targeted therapy:
Targeted therapy is the type of treatment which targets specific genetic changes that spreads to brain from metastatic disease that started in other part.
✔ Immunotherapy:
Metastatic cancer from melanoma and lung cancer can be treated by using immunotherapy. Immunotherapy is the process of treatment done by improving immune system. Many types of drugs are given to stop cancer tumors weakening the
immune system.
How and when radiation therapy and surgery are used for the treatment of brain metastases:
✔ Stereotactic radiosurgery is recommended for patients having less tumors from 1 to 3. Surgery is recommended for patients having large tumors with symptoms, afterwards stereotactic radiosurgery treatment is given.
✔ Depending on the number of tumors and speed of spreading surgery, stereotactic radiosurgery and whole brain radiation therapy are recommended.
✔ If the disease caused to other parts of the body is not becoming worst then routine treatment is continued.
Treatment of leptomeningeal metastases
Leptomeningeal metastases is caused when the cancer spreads to the meninges and spinal cord. Cerebrospinal fluid is in between of the membranes. Leptomeningeal metastases is treated by chemotherapy, lumbar puncture and also radiation therapy.
Dealing with the symptoms and side effects of brain metastases
The symptoms of brain metastases depends on the stage of the cancer. It depends on place of the cancer in the brain, how rapidly cancer is spreading and the number of cancer cells in the brain. To get rid of symptoms and other effects is the main thing in the cancer care.Though the treatment for the cancer stops or slowly done treating for symptoms may continue.
Options that help to relieve symptoms of brain metastases:
✔ To reduce swelling in the brain and to increase neurological symptoms produced by the tumor Dexamethasone (available as a generic drug) and a type of drug called a corticosteroid are used.
✔ Patients with seizures are suggested to use Anti-seizure medications.