Brain Cancer Screening and Diagnosis
Brain tumors occur as growths or masses that can develop in any part of the brain. But overall, brain cancer is extremely rare.
Deborah Forst, MD, a Mass General Cancer Center neuro-oncologist, describes the tests for diagnosing brain cancer. Dr. Forst conducts research on neuro-oncology care and is the clinical director of the Stephen E. and Catherine Pappas Center for Neuro-Oncology.
Brain tumor risk factors
For most people, the risk of a brain tumor is very low. “While we don’t know many risk factors for brain tumors, we do know a couple,” says Dr. Forst. “Exposure to high-dose radiation, like if you had radiation therapy to treat other cancer, raises your risk. Some rare genetic syndromes can also predispose you to a high risk of brain tumor.”
These conditions include:
Symptoms that could indicate a brain tumor
For most people, the journey of testing for a brain tumor begins with new neurological symptoms. A wide variety of symptoms may occur depending on which part of the brain is affected.
Possible symptoms of a brain tumor include experiencing new or worsening:
However, these symptoms can also be signs of conditions unrelated to brain cancer. Brain tumor treatment is most successful when tumors are diagnosed early. If you have any new neurological symptoms, see your doctor. Your medical team may order an imaging test as a first step to diagnosing or ruling out a brain tumor.
Imaging tests for brain cancer
A computed tomography (CT) scan (also called computed axial tomography, or “CAT”) is typically the first imaging test for diagnosing a possible brain tumor. CT scans use x-rays to create an image of your brain. Your provider also may want you to have a magnetic resonance imaging (MRI) scan, which uses radio waves to give a more detailed picture than a CT scan.
“Imaging can only identify whether a mass is present in the brain — and not all masses are tumors,” cautions Dr. Forst. A mass appearing in an image scan may be due to:
- Bleeding in the brain
- Infection
- Inflammation
- Multiple sclerosis (MS)
- Brain tumor
“If your imaging test identifies a mass suspected to be a tumor, you’ll likely meet with a neurosurgeon to discuss possible surgery,” says Dr. Forst.
Depending on the results of the imaging tests, your symptoms, and other health factors, your providers may recommend:
- A biopsy, the surgical removal of a small sample of the tumor for testing
- Tumor removal (resection), the surgical removal of as much tumor as possible, as safely as possible
- A lumbar puncture (also known as spinal tap), a procedure that involves taking a fluid sample from the base of the spine. In a recent study, this minimally invasive test was shown to diagnose brain tumors more quickly than biopsy in some cases. Spinal tap may also help diagnose other conditions such as infection or inflammation.
- An alternative strategy, which may involve a non-surgical treatment. Or your provider may recommend waiting a period of time and then doing another imaging test to see if the mass has changed.
Surgery to diagnose and treat brain cancer
A brain tumor surgery may include a biopsy or tumor resection to remove as much tumor as safely possible. The goals for brain tumor surgery are to:
- Diagnose the mass seen in an imaging test with a biopsy.
- Reduce symptoms by removing part or all of the mass.
- Improve long-term survival if the tumor is cancerous. The more of the tumor the surgeon removes, the better the chances of longer survival.
“Choosing your neurosurgeon is an extremely important step,” says Dr. Forst. “You may want to consider going to a major medical center to find an experienced neurosurgeon who has done a high volume of brain tumor surgeries.”
Pathology tests for brain tumors
Pathologic testing refers to specialized testing of brain tumor tissue. To do this, a pathologist looks at a sample of tissue under a microscope and performs genetic and molecular tests. The results help your team identify the best treatment strategy.
Dr. Forst emphasizes how critical this testing is. “This information helps us personalize your treatment, possibly including targeted therapies.”
Based on the outcome of surgery and pathology test results, your medical team may recommend additional therapies such as radiation, chemotherapy, or other medications. Mass General Brigham researchers are investigating promising new ways to treat brain cancer and improve outcomes for patients.
