Brain metastasis is known to occur when cancer cells spread from their original site to the brain. The most types of cancer that metastasize to the brain are lung, breast, colon, kidney and melanoma. They are also known as secondary tumors and occur in 10 to 30% of adult cancers. With time these metastatic tumors grow and create pressure on the brain tissue and also alter the function of the surrounding cells.
Can Brain Metastases Be Cured?
Earlier, brain metastases were perceived to be incurable. However, with recent advancements brain cancer treatments can not only control brain metastases but also in some cases may even be cured. Aggressive therapy that includes surgical resection and stereotactic radiosurgery has shown great control in brain metastases in some patients. The other treatment options include fractionated radiation and chemotherapy, which can control brain metastases temporarily or indefinitely. The goal of brain metastases treatment is to control or stop or slow down the growth of brain metastases and prevent the formation of new lesions in the brain. The treatment can provide several months or even years of remission and better quality of life by controlling the brain metastases during that period of time.
Some metastatic brain tumors occur years after the primary cancer while others metastasize, so quickly that they are diagnosed before the primary cancer. In some cases the body’s immune system destroys, the primary tumor before it becomes cancerous but it is not able to control brain metastases. In this case, the primary cancer remains unknown. The signs and symptoms of brain metastases include headaches, seizures, weakness in the arms or legs, loss of balance, memory loss, speech disturbances, changes in behavior and personality, vision disturbances or blurred vision, numbness and hearing loss. Mostly one-third of the people with other types of cancer develop metastatic brain tumor. The risk for metastatic brain tumor increases after the age of 45 years and is highest after 65 years of age.
Diagnosis And Treatment of Brain Metastases
Brain metastases remain undiagnosed till the symptoms do not appear. So, it becomes really important to get a detailed history of the patient and when suspicion of brain tumor is there, then further tests and investigations should be performed. Physical examination is also important along with vision and reflex tests to confirm the history of the patient. A neurological exam is very important to see how much the tumor has affected the brain and what functions have been compromised. A CT scan and MRI will give a detailed view of the brain and the lesions when present can be seen and their location known. Diffusion tensor imaging scan allows the surgeon and the team treating the tumor to visualize the circuitry or wiring of the brain to guide the surgery. A biopsy is done to confirm the diagnosis.
The treatment options depend upon the type of primary cancer the patient has and its response to treatment and the current status of the patient. The location and number of metastatic tumors within the brain or spine along with patient’s personal health and symptoms experienced by the patient will determine the type of treatment to be started. Surgery provides fast relief to the patient reducing the pressure inside the skull that results due to swelling and growing tumor. A surgery is performed when there is a clear correlation of neurological deficits with the location of the tumor. If the patient’s primary cancer is treatable and under control and if there is only one tumor then surgery is preferred. Radiation therapy is done to destroy cancer cells and prevent a tumor from growing and spreading. The procedures done are whole brain radiation, external beam radiation therapy, stereotactic radiosurgery and liquid radiation. Chemotherapy involves the use of chemotherapeutic agents or drugs to prevent the growth and spread of cancer cells. It can be done alone or in combination with radiation therapy. Immunotherapy is also being widely used these days for its success rate.