TUMORS OF THE CENTRAL NERVOUS SYSTEM
What is the central nervous system?
The central nervous system (CNS) is responsible for our voluntary (movement and speech) and involuntary (breathing and digestion) actions, and underlies our sensory functions (smell, hearing, sight, taste, and touch). It is composed of two main elements:
- The Encephalon, which includes the brain, the cerebellum, and the brainstem. The brain (the most extended area) is divided in two cerebral hemispheres (right and left) that control the contralateral side of the body. Each hemisphere is divided into four lobes having specific functions: frontal, parietal, occipital, and temporal. The brain contains the pituitary gland, the hypothalamus, the hippocampus, and the amygdala controlling various functions, such as the emotional ones. The cerebellum is the smaller area, responsible for controlling the balance and more complex activities, such as speaking and walking. The brainstem connects the encephalon to the spinal cord, and controls the breathing, body temperature, and blood pressure.
- The spinal cord, a bundle of nerves, cells, and nerve fibers transferring the stimuli from peripheral areas to the brain, and vice-versa, transmitting messages from the brain to the other organs.
Being the most important and delicate part of our body, it is protected by a series of barriers: meninges, cerebrospinal fluid, and bones.
What is a brain cancer?
The CNS can be affected by a neoplasia in any of its parts (brain, cerebellum, meninges, etc.), and for this reason there are a number of different types of tumor.
Tumors originating in the CNS are rare (1.6% of all tumors), whereas metastasis secondary to cancer cells migrating from other body districts (e.g., breast, lung, skin, liver) to the brain are more frequent. Among the primitive brain tumors, the most common ones are gliomas (40%) and meningiomas (30%), which grow very slowly and are malignant in less than 15% of the cases. There are also rarer tumors such as medulloblastomas and germinomas (more frequent during childhood and adolescence), primitive lymphomas (particularly malignant), neurinomas, hemangioblastomas, and craniopharyngiomas (benign).
In countries with advanced economies, 28.6 people out or 100,000 are diagnosed a brain tumor. In Italy, approximately 6,000 new cases were diagnosed in 2017.
Brain tumor risk factors:
There are still no scientific studies that have managed to establish with certitude the risk factors for the onset of brain neoplasias. Also, there are no indications on behaviors to adopt to prevent these forms of tumors. High-dose radiations are the only confirmed factor linked to the onset of brain tumors, while a hereditary genetic component has only rarely been found. Weakness of immune functions in HIV patients is also a risk factor for primitive lymphomas.
Therapies for the treatment of brain neoplasia
- Surgery: according to the type of tumor and its localization, surgical removal is the best possible option since it also allows performing a histology test and planning subsequent treatment. Surgery is often followed by radiation therapy, either alone or combined with chemotherapy, to reduce the risk of recurrence.
- Radiation therapy and chemotherapy: in addition to supporting treatment after surgery, these therapies can be administered when the tumor cannot be resected. At UPMC Hillman Cancer Center at Villa Maria we perform stereotactic radiotherapy and radiosurgery.