A brain tumor or intracranial neoplasm occurs when abnormal cells form within the brain. There are two main types of tumors: malignant or cancerous tumors and benign tumors.Cancerous tumors can be divided into primary tumors that start within the brain, and secondary tumors that have spread from somewhere else, known as brain metastasis tumors. This article deals mainly with tumors that start within the brain. All types of brain tumors may produce symptoms that vary depending on the part of the brain involved
Symptoms as consequences of increased intracranial pressure (often first noticed) Large tumors or tumors with extensive peritumoral swelling (edema) inevitably lead to elevated intracranial pressure which translates clinically into headaches, vomiting (with or without nausea), altered state of consciousness (somnolence, coma), dilation of the pupil on the side of the lesion (anisocoria), papilledema (prominent optic disc at the funduscopic eye examination). However, even small tumors obstructing the passage of cerebrospinal fluid (CSF) can also present such symptoms. Increased intracranial pressure may result in brain herniation (i.e. displacement) of certain parts of the brain, such as the cerebellar tonsils or the temporal uncus, resulting in lethal brainstem compression. In very young children, elevated intracranial pressure may cause an increase in the diameter of the skull and bulging of the fontanelles.
New techniques for imaging scans are being researched. These may help doctors better track how well treatment is working and watch for possible tumor recurrence or growth.Researchers are examining biomarkers to find better ways of using blood or other tests to determine the presence of a brain tumor before symptoms begin. Immunotherapy, also called biological response modifier (BRM) therapy, is designed to boost the body's natural defenses to fight the cancer. It uses materials either made by the body or in a laboratory to improve, target, or restore immune system function. Different methods are being studied for brain tumors, such as the use of dendritic cells or the use of vaccines aimed against a specific molecule on the surface of the tumor cells. Several methods are currently being tested in clinical trials.
"Age adjusted incidence rates for cancers of nervous system by sex and year for various registries are presented in .The average age adjusted incidence rates along with its annual percentage change for CNS cancers by sex for various registries are presented in . For studying predominance of CNS cancers it’s ranking at starting period (1982-83) and at the end of period (2002-03) in both the sexes are compared for each registry. For Mumbai registry cancers of CNS are ranked 9th in both the sexes in both the periods. For Bangalore and Chennai registries it ranked 9th in males and 8th in females in both the periods. At Delhi registry it’s ranking is 9th in males and 7th in females in both the periods. For Bhopal registry it also ranked 9th in males in both the periods and could not occupy. The average age adjusted incidence rates for CNS cancers are ranged in males from 2.53 (Chennai registry) to 4.14 (Delhi registry) while in females it ranged from 1.46 (Bhopal registry) to 2.66 (Delhi registry). The observed and expected values of age adjusted incidence rates over a period of time for cancer of CNS by sex are presented by line graphs in fig. 1. There has been increasing trend in incidence rates in both the sexes of CNS cancers were observed in all the registries except Delhi. The increase in incidence for Bhopal registry and decrease in incidence for Delhi registry was not statistically significant. More than 3%, statistically significant increase in age adjusted incidence rates of CNS cancers were noted in both the sexes in Mumbai, Chennai and Bangalore registries." source