Understanding Brain Cancer

Critical Information, From Symptoms to Treatment

Woman sweating in bed
Peter Dazeley/Photographer's Choice/Getty Images

Brain tumors are the result of uncontrolled growth of abnormal cells in the brain. They can affect children and adults, and though they are fairly uncommon, brain cancer is the second most common type of cancer in children after acute lymphocytic leukemia.

Brain tumors can be classified as malignant (cancerous) or benign (non-cancerous). Malignant tumors tend to be more aggressive than benign types, but both are very serious and can be fatal.

There are over 140 different types of brain tumors that can form in the brain. Brain tumors can be classified as primary or metastatic, depending on where they arise in the body.

Primary brain tumors originate in the brain and rarely spread outside of it. Metastatic tumors begin in another part of the body and spread to the brain through blood or lymphatic tissue. Some cancer types are more prone to spread to the brain. These types include lung cancer, breast cancer, melanoma, and kidney cancerLung cancer is the most common tumor metastatic to the brain, occurring in around 40 percent of people. Metastatic tumors are not referred to as brain cancer, but rather are referred to as a tumor metastatic to the brain. For example, lung cancer which has spread to the brain is not called brain cancer, but rather lung cancer metastatic to the brain.

Causes

We don't know exactly what causes brain tumors, but studies suggest a number of factors may play a role in their development.

Risk factors for brain tumors include:

    Symptoms

    Brain tumor symptoms vary based on the location of the tumor within the brain and the size. The severity of symptoms does not indicate how large a tumor is as small tumors can cause severe symptoms.

    Headaches are a common symptom of brain tumors but are usually accompanied by another symptom. Headaches associated with brain tumors often have characteristics that set them apart from headaches that are related to less serious conditions. Other brain tumor symptoms may include:

    • Nausea and/or vomiting
    • Seizures
    • Visual and hearing disturbances (hallucinations)
    • Problems with memory
    • Slower thought process
    • Weakness on one side of the body, or an abnormal gait
    • Fatigue or increased sleep
    • Personality changes

    Diagnosing Brain Cancer 

    If your doctor suspects you have a brain tumor, they will send you to get a magnetic resonance imaging (MRI). This imaging test gives physicians an extraordinary view of your brain and may be the only test needed to identify the possible presence of a brain tumor. In some limited cases, a CT scan may be used. PET scans, which help doctors see the activity of the brain, may help diagnose primary brain cancer but may be less helpful when it comes to metastatic disease.

    Next, a brain biopsy will likely be ordered to confirm any malignancy and the type of brain tumor present.

    If tumors are present, as shown on an MRI, and the cancer you have is a type of cancer known to metastasize, then a biopsy may not be necessary. However, with types of cancer that don't spread to the brain, a biopsy is a vital diagnostic tool.

    Brain biopsies are often done as part of a surgery to remove the tumor. The sample tissue can be examined in the operating room, allowing the surgeon to make a decision about whether to proceed with surgical treatment or not. More extensive evaluation of the tumor specimen will also be done by a pathologist which can take up to several days to receive results.

    In some cases, a closed biopsy, also called a stereotactic biopsy, is performed when the tumor is located in a region of the brain that is difficult to reach. It is the least invasive type of biopsy but does carry risks. A lumbar puncture (spinal tap) is sometimes also done.

    Surgical and Medical Treatment Options

    Brain tumors are treated by an experienced group of medical professionals. The team is usually composed of a neurosurgeon, medical oncologist, radiation oncologist, and pathologist. Many supporting team members such as oncology nurses and a social work are included as well.

    The tumor type, location, and grade will determine the treatment plan. Curative treatment is possible with some tumors, while slowing the growth or simply relieving severe symptoms may be the goal of treatment for others. Unfortunately, there may be no recommended course of treatment for some brain tumors.

    Surgical approaches in brain tumor treatment include tumor resection (complete removal) or debulking (removing as much as possible). In some cases, surgery may be the only treatment method that is required, but others may need other treatment methods such as radiation therapy. Surgery followed by radiation therapy is common with many tumors.

    Radiation therapy may be used alone or following surgery for some brain tumors. Side effects may including problems with memory loss and concentration. Swelling can be a side effect as well, which is often treated with corticosteroids.

    Chemotherapy may be utilized in some tumors that are known to respond well to chemotherapy agents such as CNS lymphoma, gliomas, or medulloblastomas. Treatment with chemotherapy is often limited due to the inability of many chemotherapy agents to cross the blood-brain barrier to reach the brain. Targeted therapy drugs are a newer category of treatment which directly attacks changes in cancer cells. Avastin is one of these drugs that works by cutting off the blood supply to a tumor, in effect "starving" the tumor.

    Continue Reading