Friday, May 13, 2011

Most common Types of Cancer - Brain and Spinal Cord Cancer

Brain and Spinal Cord Cancer
Brain and spinal cord make up the nervous system. Brain and Spinal Cord tumors originating is not very common. Most primary tumors are caused by abnormal cells growth that surround and support neurons, with a small number may be caused by gene defect from exposure to radiation or toxic chemicals. Benign tumors are noncancerous, and malignant tumors are cancerous. More than 190.000 people in US are diagnosed with a brain tumor each year alone.

Types of brains and spinal cord cancer
1. Non-infiltrating astrocytomas
Noninfiltrating astrocytomas are tumors that grow slowly and usually do not grow into the tissues around them and is considered as benign tumors.
a. Juvenile pilocytic astrocytomas
Juvenile pilocytic astrocytomas occur most often in the cerebellum in young children and is a neoplasm of the brain that occurs more often in children and young adults (in the first 20 years of life).
b. Subependymal giant cell astrocytomas
Subependymal giant cell astrocytomas grow in the ventricles and are almost always seen in children with tuberous sclerosis, but it can can become aggressive and cause obstructive hydrocephalus usually in older children and adolescents.

2. Low-grade astrocytomas (Infiltrating or diffuse astrocytomas)
An astrocytoma is a type of glioma that develops from star-shaped cells (astrocytes) that support nerve cells and accounts for about 10 percent to 15 percent of gliomas, a primary brain tumor that originates from the supportive cells of the brain. Low-grade astrocytomas is classified as a grade II tumor.
3. Intermediate- and high-grade astrocytomas
a. Intermediate- grade astrocytomas
Intermediate-grade astrocytomas (grade III) have more anaplasia and readily detectable mitotic activity, but not necrosis. The white arrow points to a mitotic figure. Glioblastomas, which are the most malignant grade of astrocytoma, are highly anaplastic and contain mitotic activity and tumour necrosis.
b. High-grade astrocytomas
High-grade astrocytomas are very different from secondary brain tumors, which originally developed elsewhere in the body and spread (metastasized) to the brain and generally respond poorly to surgery, radiation therapy, and chemotherapy.

4. Oligodendrogliomas and anaplastic oligodendrogliomas
a. Anaplastic astrocytomas
Malignant or anaplastic astrocytoma is a glioma that develops from star-shaped glial cells (astrocytes) that support nerve cells. It is an infiltrating, primary brain tumor, with tentacles that may invade surrounding tissue and is classified as more aggressive grade III astrocytomas.
b. Glioblastomas
Glioblastomas is the most common and most aggressive malignant primary brain tumor in humans, involving glial cells and accounting for 52% of all parenchymal brain tumor cases and 20% of all intracranial tumors and is and is classified as more aggressive grade IV astrocytomas.
5. Ependymomas and anaplastic ependymomas
a. Ependymomas
Ependymoma is malignant glioma originated in ependyma, a tissue of the central nervous system. Usually, in children the location is intracranial, while in adults it is spinal. The common location of intracranial ependymoma is the fourth ventricle. Rarely, ependymoma can occur in the pelvic cavity.
6. Anaplastic ependymomas
Anaplastic ependymoma is a malignant tumor of ependymomas, a tissue of the central nervous system commonly found in children and adults that are younger than 25 years old. These tumors grow rapidly and most patient eventually die if the tumor is not diagnosed and treated early.

7. Schwannomas (including acoustic neuromas)
Schwannomas is a noncancerous nerve sheath tumor arises from the nerve sheath and consisted of Schwann cells in a collagenous matrix, which normally produce the protective covering to peripheral nerves. As it grows, it can cause pressure, irritation or damage to the nerve and affect the sensations of hearing and balance.

8. Spinal cord tumors
Primary cancerous tumors of spinal cord are not common. Most of spinal cord tumors are secondary tumors, and are spread from other parts of the body but they can interfere with the transmitting signals from the brain to the spinal cord, leading to loss of function and sensation.

9. Lymphomas
Lymphomas is a cancer in the lymphatic cells of the immune system, including Hodgkin disease and non-Hodgkin lymphoma.
a. Hodgkin disease
Hodgkin disease is a type of lymphoma found in the lymph nodes, named after Thomas Hodgkin who published the first description of lymphoma in 1832 and can spread systemically from one lymph node group to another.
b. Non-Hodgkin lymphoma
Non-Hodgkin lymphomas are caused by abnormal growth of cancerous white blood cells (T and B cells) due to mutation or alternation of cells DNA. They can spread to almost any other part of the body.

10. Brain tumors that occur more often in children
a. Astrocytomas
Astrocytomas in children age from 5 -8 age are usually benign, low grade which are localized and grow slowly.
b. Ependymomas
Ependymomas arises from cells of the ependymal lining located in tiny passageways (ventricles) in the brain and interfered with the flow of cerebrospinal fluid (CSF), causing problem of speak, walk, eat, see and other normal functions in children.

c. Medulloblastomas
Medulloblastomas are the most common types of brain cancers in children originated in the cerebellum (10-20%) or posterior fossa (40%) and occurred more often in boys than girls between age 5 to 10.

11. Etc.

Grades of a tumor
The grades of tumor is classified according to abnormal cancer cells how quickly the abnormal cancer cells in the tumor grow and spread look under a microscope by using tissue removed for biopsy.
1. Grade I
Slow growth tumor, rarely spreads into nearby tissues can beremove the entire tumor by surgery.
2. Grade II
Slow growth tumor grows slowly may spread into nearby tissue and become a higher-grade tumor.
3. Grade III
Quickly grows tumor and is likely to spread into nearby tissues.
4. Grade IV
Aggressive growth tumor likely spread to nearby tissues and other parts of the brain. It is difficult to treat successfully. The chance of recovery depends on the type, grade, and location of the tumor.

Symptoms
1. Headache
Headache is one of first symptoms for person with brain ans spinal cord tumors. The symptom is worse when wake up and gradual improve throughout the day.

2. Seizures
Seizure happened due to sudden, abnormal electrical activity in the brain, can be last in 2 minutes or less. Not all seizure are convulsions, but some os them are. It cab be divided into two main groups. Focal seizures or partial seizures, happen in just one part of the brain, a common symptom of a brain tumor and generalized seizures happens to both sides of the brain.

3. Mental and personal change
Not all patients with brain and spinal cord cancer may result in mental and personal change, but depending to the location of the tumors, it may affect the ability of memory, speech, communication, etc.
4. Mass effect
If the tumor growth affect the normal intracranial pressure (IICP) volume such as accumulation/restriction of fluid, it may cause mass effect, leading to vomiting, nausea etc.

5. Focal symptoms
Many patients with brain and spinal cord tumors may result in certain focal symptom which affect a specific region of the body such as weakness in the left arm, the right leg, buzzing sounds in the ears or hearing loss, decreased muscle control, etc. These types of symptom are important for the doctors to determine the exact location of the tumors.

6. Loss of appetite
May be caused by the use of medication in chemotherapy

7. Etc.

Causes and risk factors
1. Family history
Although many people with brain and spinal cord cancer do not have a family history of the diseases, but if one of you direct family have the following disorders, you may be at a high risk
a. Neurofibromatosis type 1 (NF-1)
Neurofibronatosis type 1 is a genetic disorder which can either caused by inherited from the parent or genetic change after birth of the single gene NF-1 as a result of the mutation of a gene on the long arm of chromosome 17, leading to cognitive and learning disability.

b. Neurofibromatosis type 2 (NF- 2)
Neurofibromatosis type 2 (NF- 2) is associated with vestibular schwannomas (acoustic neuromas) and, in some patients, meningiomas or spinal cord ependymomas. Changes in the NF2 gene are responsible for neurofibromatosis type 2. Like NF1, the gene changes are inherited from parent or occurred before birth in children without a family history.

c. Tuberous sclerosis
Tuberous sclerosis is a rare, multi-system genetic disease. People with this condition may have causes non-malignant tumors to grow in the brain and along with benign tumors of the skin, heart, kidneys, and other organs. It is caused by changes in either the TSC1 or the TSC2 gene. These gene changes can be inherited from a parent, but in most cases they develop in people without a family history.

d. Von Hippel-Lindau disease
Von Hippel-Lindau disease is a rare, autosomal dominant genetic condition associated with an inherited tendency to develop benign or cancerous tumors in different parts of the body, including hemangioblastomas (blood vessel tumors) in the brain, spinal cord, or retina, as well as tumors of the inner ear, kidney, adrenal gland, and pancreas, due to change in the VHL gene on the short arm of chromosome 3. In most cases the gene changes are inherited, but in some cases the changes happen very early in life in people whose parents don't have them

e. Li-Fraumeni syndrome
Li-Fraumeni syndrome is a rare autosomal dominant hereditary disorder. People with this condition are at higher risk for developing gliomas, along with certain other types of cancer caused by changes in the p53 tumor suppressor gene.

f. Turcot syndrome
Turcot syndrome is a condition associated with biallelic DNA mismatch repair mutations during DNA replication and recombination such as repairing erroneous insertion, deletion and mis-incorporation of bases.

g. Etc.

2. Immune disorder
People with impaired immune systems have an increased risk of developing lymphomas of the brain or spinal cord. Lymphoma is a cancer in the lymphatic cells developed within the lymphatic system, a part of the body’s immune system at birth or caused by treatments that required to suppress the immune system such as preventing rejection of transplanted organs, or the result of diseases such as the acquired immunodeficiency syndrome (AIDS).

3. Radiation exposure
Radiation exposure is considered as one the environmental risk factor for brain tumors, such as radiation therapy. Researcher found that children with ringworm of the scalp (a fungal infection)and leukemia were treated with low-dose radiation therapy have an increased risk of brain tumors as they got older.
But for most patients with other brain cancers, the benefits of radiation therapy far outweigh the risk of developing a brain tumor years later.

4. Toxic chemicals
Prolonged period of exposure to toxins in months or years can mutation of DNA of cell in replication and division. Study found that chemicals identified as being causally associated with cancers in humans, have all been shown to produce cancer in laboratory animals.

5. Infection with certain viruses
Virus can cause genetic changes in cells by deleting and adding genes and genetic materials into your cells, causing DNA alternation, such as Cervical cancer can be caused by human papilloma virus (HPV), primary liver cancer caused by hepatitis B and C viruses and lymphomas caused by Epstein-Barr Virus.

6. Exposure to electromagnetic fields
Study in adults, found that long term exposure to electromagnetic field exposure showed very small increases in leukemia and brain tumors.

7. Etc.

Diagnosis
1. Magnetic resonance imaging (MRI)
By using radio waves and magnetic fields to take pictures, MRI scan provides very high quality of a cross-sectional slice and lengthwise slices of the brain and spine, thus providing the better and detail image of location of tumor and the surrounding structures. It is one of most likely early test ordered by a doctor for people suspected to have brain and spinal cord tumor.

2. Positron emission tomography (PET) scan
Positron emission tomography (PET) scan is a nuclear medicine imaging technique with radioactive material may be injected into a vein, inhaled or swallowed to produce a three-dimensional image or picture of functional processes in brain with an aim to detect location of the tumor and surrounding structure. More radioactive material accumulated often corresponds to areas of disease and shows up as brighter spots on the PET scan.

3. Computerized tomography (CT)
CT scan is always the first test to be done if there is any suspicious of tumors. It is useful to detect the location of the tumor as it takes many X-ray images, creating detailed cross section pictures.

4. A myelogram
A myelogram, an x-ray examination after injecting dye (oil-based liquid that is removed after the x-ray exam while water-based liquid that is not removed) into the fluid-filled space around the spinal cord with aim to detect any abnormality of the spinal cord and surrounding structures. Radiologist who performs the test interprets the information then reports to your doctor.

5. Biopsy
A biopsy is a test of removal sample of cells or tissues for examination and determination of the grade and type of the tumors by examining them under a microscope by a pathologist or chemically, if the location of the tumor allows the test to be done without major risk to the patient.

6. Etc.


Treatment Options
The objective of any cancer treatment is to eliminate the cancer and prevent the chance of recurrence and types of the treatment are depended on types of caner, position and grade.
A. General treatments
1. Surgery
Surgery is one of most common treatment of choice for many brain and spinal cord tumors if they can be removed without causing major neurological problems. Sometime surgery is necessary to relieve the pressure on your brain from the tumor and conbined with other treatment depending such as radiation therapy. Complications during or after surgery are rare, but it can happen, such as side effects of bleeding, infections, or reactions to anesthesia.

2. Dexamethasone
Dexamethasone is a class of steroid drugs and used as immunosuppressant for patient who undergoing chemotherapy to counteract certain side-effects of their anti-tumor treatment to relieve the symptoms of vomiting and nausea, prevent the development of edema and treat spinal cord compression.

3. Radiation therapy
Radiation therapy is another most effective treatment for brain and spinal cord tumors locally by using X-rays or other high-energy rays to destroy cancer cells before and after surgery and shrink tumors if necessary. It most of the time used in combination with other treatments but can be used alone depending to diagnosis. The treatment is performed by radiation oncologist. The aims of radiation therapy is to kill tumor cells but normal cells of normal brain and spinal tissue is also damaged.

4. Chemotherapy
Chemotherapy most of the time uses medications to eliminate cancer cells with IV by giving of medicine directly into a vein or taking orally. As the medications travel through our bloodstream, they kill cancer cells throughout the body including the cancers in brain and spinal cord. Chemotherapy can be given orally or through a needle in the vein. Since it is designed to kill cancer cells which divide quickly, it also affects the normal cells in the bone marrow, the lining of the mouth and intestines, and the hair follicles and causes symptoms of hair loss, mouth sores, loss of appetite, nausea and vomiting, diarrhea, low white blood cell and low blood platelet counts.

5. Etc.






No comments:

Post a Comment

Post a Comment