Brain Cancer: Types, Risk Factors, Symptoms, Treatment And Long Term Outlook

What is brain cancer?

Brain cancer is the development of tumor (either malignant or benign) cells in the brain characterized by a headache that  usually worse in the morning, drowsiness, memory defect and so on.

Cancer cells grow to form a mass of cancer tissue (tumor) that interferes with brain functions such as muscle control, sensation, memory, and other normal body functions. Tumors composed of cancer cells are called malignant tumors, and those composed of mainly noncancerous cells are called benign tumors. Cancer cells that develop from brain tissue are called primary brain tumors while tumors that spread from other body sites to the brain are termed metastatic or secondary brain tumors. Statistics suggest that brain cancer occurs infrequently (1.4% of all new cancer patients per year), so it is not considered to be a common illness and is likely to develop in about 23,770 new people per year with about 16,050 deaths as estimated by the National Cancer Institute (NCI) and the American Cancer Society. Only about 5% of brain tumors may be due to hereditary genetic conditions such as neurofibromatosis, tuberous sclerosis, and a few others.

What are the types of brain cancer?

Brain cancer is named based on where in your body it develops. Brain cancer begins in your brain. This is sometimes referred to as primary brain cancer.

You can also have cancer that has spread to your brain after starting somewhere else in your body. This is called metastatic brain cancer. Cancerous tumors in the brain are typically metastatic and not due to primary brain cancer.

There are also types and grades of brain tumors. The tumor type is based on where it is located in your brain, and the grade indicates how quickly a tumor grows. The grades range from 1 to 4, with grade 4 having the fastest growth.

There are more than 120 types of brain tumors. However, there is no standard for naming them according to type, and there are many subtypes. Different doctors might use different names for the same tumor.

What causes brain cancer?

Mostly the causes of brain cancer is unknown.

Risk factors

There are many varieties of brain cancer risk factors. The cause of brain cancer is still largely unknown. Although some genetic conditions and environmental factors may contribute to the development of brain cancer, the risk factors are much less defined for brain cancer than for other cancers in the body. Also, the risk of developing primary brain cancer is very low. The American Cancer Society estimates the risk over a lifetime is less than 1%.

It’s important to remember that a brain cancer risk factor only affects the probability of developing brain cancer over a lifetime. For example, if you’ve received radiation therapy to treat another cancer, or if you’ve worked in an industry where you handled potentially cancerous chemicals, you may want to discuss with your doctor what it means for your individual risk of developing brain cancer.

There is no definitive cause of brain tumors or brain cancer, though certain factors may increase the risk. They include:

1. Age: People who are 65 years and older are more likely to develop brain cancer than people at young age. The age factor varies depending on the cell type and location of the tumor. Adults have a very low risk of developing medulloblastomas, while gliomas are most common in adults. The incidence of meningiomas and craniopharyngiomas are far more frequent in adults over age 50, but again, these tumors may occur at any age.

2. Compromised immune system: Some people with compromised immune systems have an increased risk of developing lymphomas of the brain.

3. Genetic links: Family history may affect the likelihood of developing certain diseases. Von Hippel-Lindau disease, Li-Fraumeni syndrome and Neurofibromatosis (NF1 and NF2) are inherited conditions that have been found in families with a history of rare brain tumors. Otherwise, there is little evidence that brain cancer runs in families.

4. Gender: Certain cancers, like medulloblastomas, are frequently found in men, while meningiomas are as twice  likely develop in women.

5. Chemical exposure: Exposure to certain industrial chemicals or solvents has been linked to an increased risk in developing brain cancer. Although it is not conclusive, evidence has found a higher incidence of certain types of brain tumors in individuals who work in oil refining, rubber manufacturing and drug manufacturing.

6. Previous radiation treatment: Exposure to radiation therapy, particularly at a young age, may increase the likelihood of developing brain cancer.

What are the symptoms of brain cancer?

The symptoms of brain cancer depend on the size and location of the tumor.

Common brain cancer symptoms include:

Headaches that are usually worse in the morning

Difficulty walking

Difficulty thinking

Drowsiness

Nausea and vomiting

A lack of coordination

A lack of balance

Memory defect

Speech problems

Vision problems

Uncontrolled movement of muscle

Personality changes

Abnormal eye movements

Muscle twitching

Unexplained passing out, or syncope

Numbness or tingling in the arms or legs

Seizures.

Many of the symptoms of brain cancer are also caused by other, less-serious conditions. There’s no need to panic if you’re experiencing these symptoms, but it’s a good idea to visit your doctor to have your symptoms investigated, just in case.

What are the methods of diagnosing brain cancer?

A complete and accurate diagnosis is the first step in developing a brain cancer treatment plan. A multidisciplinary team of experts uses a variety of tests and tools for diagnosing brain cancer, evaluating the disease and customizing a treatment plan based on each individual patient’s disease and situation. Throughout treatment, imaging tests track the size of the tumor(s) and monitor response to treatment, so the treatment plan may be modified as needed.

Common tools used for diagnosing brain cancer include:

. Lab tests

The main lab test for brain cancer is advanced genomic testing, which analyzes a tumor’s genomic profile to look for DNA alterations that may be causing the cancer to grow. By identifying the mutations (changes) in a cancer cell's genome, doctors may better understand the tumor’s behavior and tailor treatment based on these findings.

. Biopsy

Whenever possible, a full surgical resection of the cancerous tissue is performed. If such a resection threatens neurological function, a lesser resection, or simple biopsy, is performed.

A biopsy for brain cancer involves the removal of a small amount of the cancerous brain tissue. This helps evaluate the tumor in order to develop a treatment plan. A needle biopsy may be performed for tumors in difficult-to-reach or critical areas of the brain.

. Nuclear medicine bone scan

By capturing images of bones on a computer screen or on film, a nuclear medicine bone scan may reveal the location of the cancer, as well as whether the brain cancer has spread to the bone. To perform the scan, a small dose of radioactive material is injected into a blood vessel, where it travels through the bloodstream, gathers in the bones, and is detected by a scanner through nuclear imaging.

. Angiography

This procedure uses X-rays to obtain multiple, detailed, 3-D images of the blood vessels in the brain. An angiography may be used to plan the surgical resection of a tumor near an area of the brain with many blood vessels. Sometimes, this test is used to embolize (close off) blood vessels feeding a tumor prior to surgery.

. Other imaging tests

Imaging tests for brain cancer produce pictures of the brain to determine the location and grade of brain tumors. A contrast agent may be used to distinguish normal and abnormal brain tissue.

Imaging tests used in brain cancer diagnosis include:

1. MRI (magnetic resonance imaging): MRIs are used to look for brain and spinal cord tumors because they tend to provide greater detail than CT scans. However, for the bones and skull, MRI does not provide the same image quality as CT scans and, therefore, may not show the effects of tumors on the skull.

2. Computed Tomography (CT scan): CT scans create detailed images of the body’s soft tissues and may be performed when MRI is not an option, such as with overweight or claustrophobic patients. CT scans also show greater detail of bone structures near the tumor.

3. PET (positron emission tomography) scan: PET scans are more often used for fast-growing, high-grade tumors. Following treatment, a PET scan may be performed to determine whether tumor tissue remains.

What are the stages of brain cancer?

The staging process assesses the spread of cancer beyond the original site. Brain cancer does not behave in the same way as other cancers. Tumors may migrate within the brain, but it is very rare for primary brain tumors to spread outside of the brain, or away from the central nervous system (CNS).

Consequently, brain cancer is usually graded rather than staged. The brain tumor grading system features four distinct grades and provides your care team with an understanding of how the tumor grows. This process helps doctors match brain cancer treatments to individual needs.

Assessing brain tumors.

To determine the growth and development of tumors in the brain, doctors focus on the characteristics of the tumor and its effect on functionality. The main factors used to assess brain tumors include:

Size and location

Type of tissue or cells affected

Resectability (the likelihood that part or all of the tumor can be removed by surgery)

The spread of the cancer within the brain or spinal cord

The possibility the cancer has spread beyond the brain or CNS

A complete assessment will also factor in age and brain cancer symptoms that are limiting basic functions, such as speech, hearing or movement.

Brain cancer grading is much different than staging other cancers in the body. Cancers in the lung, colon and breast are staged based on their location in the body, size, lymph node involvement and possible spread. Tumors in the brain are graded based on how aggressive the tumor cells appear under a microscope.

The grade and resectability of the tumor will help guide treatment decisions. Surgery depends on the tumor’s accessibility (location), size, extent (spread within the brain) and the patient’s overall health (including medical history).

Grade I (grade 1 brain cancer): The tumor grows slowly and rarely spreads into nearby tissues. It may be possible to completely remove the tumor with surgery.

Grade II (grade 2 brain cancer): The tumor grows slowly but may spread into nearby tissues or recur.

Grade III (grade 3 brain cancer): The tumor grows quickly, is likely to spread into nearby tissues, and the tumor cells look very different from normal cells.

Grade IV (grade 4 brain cancer): The tumor grows and spreads very quickly, and the tumor cells do not look like normal cells.

Brain metastasis: Secondary brain tumors, which have spread to the brain from another location in the body, are much more common than primary brain tumors. These tumors are also becoming increasingly more common as individuals do better with cancer treatment and live longer, giving the original cancer the opportunity to spread to the brain.

Some cancers that commonly spread to the brain are lung, breast, colon, kidney, melanoma, thyroid and uterine. Lung cancer is the most common form of brain metastasis. In fact, lung cancer staging often involves a brain scan.

Brain metastases will likely be assessed through the Tumor, Node, Metastasized (spread) staging system (TNM). Sometimes, individuals are diagnosed with brain or spinal metastases before they realize they have another, primary cancer.

How to treat brain cancer?

There are several treatments for brain cancer. Treatment for primary brain cancer will be different from treatment for cancers that have metastasized from other sites.

You may receive one or more treatments depending on the type, size, and location of your brain tumor. Your age and general health are also factors.

Treatments include:

Chemotherapy and radiation therapy

You may be given chemotherapy drugs to destroy cancer cells in your brain and to shrink your tumor. Chemotherapy drugs may be given orally or intravenously.

Radiation therapy may be recommended to destroy tumor tissue or cancer cells that can’t be surgically removed. This is done with high-energy waves, such as X-rays.

Sometimes, you may need to undergo chemotherapy and radiation therapy at the same time. Chemotherapy may also be done after radiation treatment.

  Surgery

Surgery is the most common treatment for brain cancer. Sometimes, only part of your tumor can be removed due to its location.

In some instances, a tumor is located in a sensitive or inaccessible area of your brain, and surgery to remove it can’t be performed. These kinds of tumors are referred to as inoperable.

  Biologic drugs

Your doctor may prescribe biologic drugs to boost, direct, or restore your body’s natural defenses against your tumor. For example, the drug bevacizumab works to stop the growth of blood vessels that supply tumors.

  Other medications

Your doctor may prescribe medications to treat symptoms and side effects caused by your brain tumor and brain cancer treatments.

  Clinical trials

In advanced cases of brain cancer that don’t respond to treatment, clinical trial therapies and medications may be used. These are treatments that are still in the testing phase.

  Rehabilitation

You may need to go through rehabilitation if your cancer has caused damage in your brain that affects your ability to talk, walk, or perform other normal functions.

Rehabilitation includes physical therapy, occupational therapy, and other therapies that can help you relearn activities.

  Alternative therapies

There isn’t a lot of scientific research that supports the use of alternative therapies to treat brain cancer. However, your doctor may recommend that you combine alternative therapies or lifestyle changes with conventional treatments.

For example, they may recommend a healthy diet and vitamin and mineral supplementation to replace nutrients lost from your cancer treatment. They may also recommend acupuncture and certain herbs.

You should talk to your doctor before taking herbs because some can interfere with medications.

  Long-term outlook

Your long-term outlook depends on the type, size, and location of your brain tumor. Some types of brain cancer generally have a low survival rate.

However, the American Cancer Society reports that for some types of brain cancer, up to 90 percent of patients between the ages of 20 and 44 survive for 5 years or longer.

Some brain cancer treatments can increase your risk of getting other cancerous tumors or may cause cataracts, which is clouding of the eyes.

  Reducing your risk of brain cancer

There’s no way to prevent brain cancer, but you can reduce your risk of getting it if you:

Avoid exposure to pesticides and insecticides

Avoid exposure to carcinogenic chemicals

Avoid smoking

Avoid unnecessary exposure to radiation.

Preventions of brain cancer

Although there is no way to prevent brain cancers, early diagnosis and treatment of tumors that tend to metastasize to the brain may reduce the risk of metastatic brain tumors. The following factors have been suggested as possible risk factors for primary brain tumors: radiation to the head, HIV infection, and environmental toxins. However, no one knows the exact causes that initiate brain cancer, especially primary brain cancer, so specific preventive measures are not known. Although web sites and popular press articles suggest that macrobiotic diets, not using cell phones, and other methods will help prevent brain cancer, there is no reliable data to support these claims.

Sources:

www.medicinenet.com

www.healthline.com

www.cancercenter.com