Friday, January 20, 2012

Brain Cancer: causes and prevented of brain cancer

What is the causes of brain cancer ?
As with tumors elsewhere in the body, the exact cause of most brain tumors is unknown,
The following factors have been proposed as possible risk factors for primary brain tumors, but whether these factors actually increase an individual's risk of a brain tumor is not known for sure.
  • Radiation to the head 
  • An inherited (genetic) risk
  • HIV infection 
  • Cigarette smoking
  • Environmental toxins (for example, chemicals used in oil refineries, embalming chemicals, rubber industry chemicals) 


How is Brain Cancer be Prevented ?
In general, there is no known way to prevent brain cancers. However, early diagnosis and treatment of tumors that tend to metastasize to the brain may reduce the risk of metastatic brain tumors.
  • Avoiding or reducing contact with radiation (especially to the head) 
  • Avoiding toxic chemicals associated with the oil and rubber industry, embalming chemicals, and other environmental toxins may help prevent brain cancers. 
  • Avoiding HIV infection is also suggested. 
The popular press and some web sites suggest that avoiding cell phone use and using a macrobiotic diet will help avoid brain cancer. Currently, there is no good evidence for these claims. In December 2010, a large study of about 59,000 cell phone users, with use times ranging over five to 10 years, claims that no substantial change in brain cancer incidence could be found in these individuals. Investigators suggest that "high usage" of cell phones over long time periods is yet to be investigated. However, for those who want to minimize any radiation dose from cell phones, the reader can consult the web for a list of phones that produce the highest and lowest radiation levels .

Brain cancer - What are treatments and risks ?

What are the treatments of brain cancer ?
Treatment for brain cancer should be individualized for each patient. The treatments  are based on the patient's age and general health status as well as the size, location, type, and grade of the tumor. In most cases of brain cancer, surgery, radiation, and chemotherapy are the main types of treatment. Often, more than one treatment type is used.


What are the types of  Treatments for Brain Cancer  ?
Treatment of brain cancer is usually complex. Most treatment plans involve several doctors consulting . The team of doctors includes neurosurgeons (surgical specialists in the brain and nervous system), oncologists, radiation oncologists (doctors who practice radiation therapy), course, also primary health-care provider. A patient's team may include a dietitian, a social worker, a physical therapist, and probably other specialists. The treatment can be done according to the location of the tumor, its size, grade, and type, the patient's age, and any additional medical problems that the person may have. The most widely used treatments are surgery, radiation therapy, and chemotherapy. In some cases, more than one of these treatment types is used.


Surgery 
  • The purposes of surgery are to confirm that the abnormality seen on the brain scan is indeed a tumor, to assign a grade to the tumor, and to remove the tumor. If the tumor cannot be removed, the surgeon will take a sample of the tumor to identify its type and grade.
  • In some cases, mostly in benign tumors, symptoms can be completely cured by surgical removal of the tumor. A neurosurgeon will attempt to remove the tumor when possible. Patients may undergo several treatments and procedures before surgery. They may be given a steroid drug, such as dexamethasone (Decadron), to relieve swelling. They may be treated with an anticonvulsant drug, such as levetiracetam (Keppra), phenytoin (Dilantin), or carbamazepine (Tegretol), to relieve or prevent seizures. Surgery for tumors is to remove as much of the tumor as is safely possible with the minimal possible loss in brain function. Some surgeries are done awake or under light sedation for the purpose of mapping language function. For surgery done under general anesthesia, an endotracheal tube is placed, while for those done awake, a laryngeal mask airway (or no airway) is placed and the patient is deeply sedated. The head is appropriately positioned using a clamp system that holds the skull motionless. An image-guided navigation system is often used to help determine the precise location of the incision. The scalp is prepped, after the hair is clipped, the planned incision line is infiltrated with local anesthesia, and the scalp is then incised and pushed aside to expose the skull bone. A portion of the skull is temporarily cut away and the lining tissues of the brain are opened. If it is necessary to determine whether brain function is compromised, the patient is awakened from sedation in order to respond as mapping procedures are carried out. In either case, tumor resection is then carried out. A portion of the tumor is usually sent to a pathologist for analysis. The surgeon may also decide to place biodegradable polymer wafers that deliver chemotherapy drugs (Gliadel wafers) into the tumor cavity. Once the tumor resection is complete, the membranes surrounding the brain are closed and the skull is closed, often with the use of titanium plates and screws that help hold it rigidly in its desired position. The scalp is closed; some surgeons use drains placed under the scalp for a day or two after surgery to minimize the accumulation of blood or fluid.
  • Stereotactic radiosurgery is a newer "knifeless" technique that destroys a brain tumor without opening the skull. CT or MRI scan is used to pinpoint the exact location of the tumor in the brain. High-energy radiation beams are trained on the tumor from different angles. The radiation destroys the tumor. Equipment used to do radiosurgery varies in its radiation source; a gamma knife uses focused gamma rays, and a linear accelerator uses photons, while heavy-charged particle radiosurgery uses a proton beam. 
Radiation therapy (also called radiotherapy) is the use of high-energy rays to kill tumor cells and stop them from growing and multiplying.
  • Radiation therapy is sometimes used for people who cannot undergo surgery. In other cases, it is used after surgery to kill any tumor cells that may remain. 
  • Radiation therapy is a local therapy. This means that it affects only cells in its path. It does not harm cells elsewhere in the body or even elsewhere in the brain. Radiation can be administered in either of two ways. 
  • External radiation uses a high-energy beam of radiation targeted at the tumor. The beam travels through the skin, the skull, healthy brain tissue, and other tissues to get at the tumor. The treatments are usually given five days a week for about four to six weeks. Each treatment takes only a few minutes. The gamma knife and cyber knife are two terms that describe methods that use external radiation to kill cancer cells in the brain. 
  • Internal or implant radiation uses a tiny radioactive capsule that is placed inside the tumor itself. The radiation emitted from the capsule destroys the tumor. The radioactivity of the capsule decreases a little bit each day; the amount of radioactivity of the capsule is carefully calculated to run out when the optimal dose has been given. You need to stay in the hospital for several days while receiving this treatment. 
Chemotherapy is the use of powerful drugs to kill tumor cells.
  • A single drug or a combination may be used. 
  • The drugs are given by mouth or through an IV line. Two drugs, temozolomide (Temodar) and bevacizumab (Avastin), have recently been approved for the treatment of malignant gliomas. They are more effective and have fewer adverse effects when compared with older drugs. Temozolomide has another advantage in that it is administered orally, eliminating the need for intravenous lines and hospital stays for chemotherapy.
  • Chemotherapy is usually given in cycles. A cycle consists of a short period of intensive treatment followed by a period of rest and recovery. Each cycle lasts a few weeks. 
  • Most regimens are designed so that two to four cycles are completed. There is then a break in the treatment to see how the tumor has responded to the therapy. 
  • The side effects of chemotherapy are well known and are very difficult to tolerate for some people. They include nausea and vomiting, mouth sores, loss of appetite, loss of hair, and many others. Some of these side effects can be relieved or improved by medication.
New therapies (for example, use of nanotechnology to deliver drugs to tumor cells) for cancer are being developed all the time. When a therapy shows promise, it is studied in laboratories and improved as much as possible. It is then tested on people with cancer; these tests are called clinical trials.
  • Clinical trials are available for virtually every kind of cancer. 
  • The advantage of clinical trials is that they offer new therapies that may be more effective than existing therapies or have fewer side effects. 
  • The disadvantage is that the therapy has not been proven to work or does not work in everyone. 
  • Many people with cancer are eligible for participation in clinical trials. 
There are many "holistic" and other treatments for brain tumors cited in Internet sites, health magazines, and other publications. Patients should discuss any such substances with their doctors before buying and using these items.

Brain cancer - The symptoms and signs of brain cancer

What are the symptoms and sign of brain cancer ?
The symptoms of brain tumors are numerous and not specific to brain tumors.  The way to make sure the symptoms of  brain cancer  is  undergo diagnostic testing. Early symptoms may not occur; but the diagnostic test  will do with the following reason  : 
  • The symptoms are caused by the tumor pressing on or encroaching on other parts of the brain and keeping them from functioning normally. 
  • Some symptoms are caused by swelling in the brain primarily caused by the tumor or its surrounding inflammation. 
  • The symptoms of primary and metastatic brain cancers are similar in men, women, and children.
The following symptoms are most common:
  • Headache 
  • Weakness 
  • Clumsiness 
  • Difficulty walking 
  • Seizures 
Other nonspecific symptoms and signs include the following: 
  • Altered mental status: changes in concentration, memory, attention, or alertness 
  • Nausea, vomiting: especially early in the morning 
  • Abnormalities in vision (for example, double vision, loss of peripheral vision)
  • Difficulty with speech
  • Gradual changes in intellectual or emotional capacity 
Brain Cancer
  
In many people, the onset of these symptoms is very gradual and may be overlooked by both the person with the brain tumor and the person's family members, even for long time periods. Occasionally, however, these symptoms appear more rapidly. In some instances, the person acts as if he or she is having a stroke. In some patients, the symptoms may be more pronounced if the cancer is located mainly in a specific brain lobe that is usually responsible for certain body functions. For example, behavioral changes may predominate in frontal-lobe cancers while difficulty with speech or movements may predominate in cancers within the parietal lobe.

Brain cancer: What are the causes of brain cancer ?

What are the causes of brain cancer ?

picture of brain cance
As with tumors elsewhere in the body, the exact cause of most brain tumors is unknown.
The following factors have been proposed as possible risk factors for primary brain tumors, but whether these factors actually increase an individual's risk of a brain tumor is not known for sure.
* Radiation to the head
* An inherited (genetic) risk
* HIV infection
* Cigarette smoking
* Environmental toxins (for example, chemicals used in oil refineries, embalming chemicals, rubber industry chemicals)

Brain cancer - What is brain cancer ?

What is Brain cancer ?
Brain cancer is  the consequence of abnormal growths of cells in the brain. Brain cancers can arise from primary brain cells, the cells that form other brain components (for example, membranes, blood vessels), or from the growth of cancer cells that develop in other organs and that have spread to the brain by the bloodstream (metastatic brain cancer).

Knowing of brain cancer or brain tumors :
  • Although many growths in the brain are popularly called brain tumors, not all brain tumors are cancerous. Cancer is a term reserved for malignant tumors. 
  • Malignant tumors grow and spread aggressively, overpowering healthy cells by taking their space, blood, and nutrients. Like all cells of the body, tumor cells need blood and nutrients to survive. This is especially a problem in the brain, as the added growth within the closed confines of the skull can lead to an increase in intracranial pressure or the distortion of surrounding vital structures, causing their malfunction. 
  • Tumors that do not grow aggressively are called benign. Almost all tumors that begin in the brain do not spread to other parts of the body. The major difference between benign and malignant tumors is that malignant tumors can invade the brain tissues and grow rapidly. This rapid growth in the confines of the skull can quickly cause damage to nearby brain tissue. 
  • In general, a benign tumor is less serious than a malignant tumor. However, a benign tumor can still cause many problems in the brain, but usually the problems progress at a slower rate than malignant tumors. 
Sometimes people confuse brain aneurysms with brain tumors. Brain aneurysms are not tumors; they are areas in the brain arteries or veins that are abnormally weak and expand to form a ballooning or expansion of the vessel wall. They seldom produce any symptoms unless they begin to leak blood into the surrounding brain tissue. Aneurysms may be congenital (present at birth) or expanded or formed in brain vessels after vessel damage (for example, trauma, atherosclerosis, high blood pressure) but are not formed from cancer cells. Unfortunately, when aneurysms produce symptoms, they can resemble those produced by brain tumors.

Primary brain tumors
Primary brain tumor is The brain that  made up of many different types of cells and tumors that arise from a brain cell type .
  • Cancers occur when one type of cell transforms and loses its normal characteristics. Once transformed, the cells grow and multiply in abnormal ways.
  • As these abnormal cells grow, they become a mass of cells, or tumor. 
  • Brain tumors that result from this transformation and abnormal growth of brain cells are called primary brain tumors because they originate in the brain.
The most common primary brain tumors are gliomas, meningiomas, pituitary adenomas, vestibular schwannomas, primary CNS lymphomas, and primitive neuroectodermal tumors (medulloblastomas). The term glioma is an expansive one since it includes numerous subtypes, including astrocytomas, oligodendrogliomas, ependymomas, and choroid plexus papillomas.

These primary tumors are named after the part of the brain or the type of brain cell from which they arise. Brain tumors vary in their growth rate and ability to cause symptoms. The cells in fast growing, aggressive tumors usually appear abnormal microscopically.

According to The National Cancer Institute (NCI) uses a grading system to classify tumors. The NCI lists the following grades:
  • Grade I: The tissue is benign. The cells look nearly like normal brain cells, and cell growth is slow.
  • Grade II: The tissue is malignant. The cells look less like normal cells than do the cells in a grade I tumor. 
  • Grade III: The malignant tissue has cells that look very different from normal cells. The abnormal cells are actively growing. These abnormal-appearing cells are termed anaplastic. 
  • Grade IV: The malignant tissue has cells that look most abnormal and tend to grow very fast. 

Metastatic brain tumors
Metastatic brain tumors are made of cancerous cells that spread through the bloodstream from a tumor located elsewhere in the body. The most common cancers that spread to the brain are those arising from cancers that originate in the lung, breast, and kidney as well as malignant melanoma, a skin cancer. The cells spread to the brain from another tumor in a process called metastasis. The process metastasis occurs when cancer cells leave the primary cancer tissue and enter either the lymphatic system to reach the blood or the bloodstream directly. These cancer cells eventually reach the brain tissue through the bloodstream where they develop into tumors. Metastatic brain tumors are the most common type of tumor found in the brain and are much more common than primary brain tumors. Metastatic tumors are usually named after the type of tissue from which the original cancer cells arose (for example, metastatic lung or metastatic breast cancer). Brain blood flow usually determines where the metastatic cancer cells will lodge in the brain; about 85% locate in the cerebrum (the largest portion of the brain, located in the upper part of the skull cavity). But in fact , the majority of metastatic brain tumors occur at more than one site in the brain tissue.