Glioma, the brain tumor, affects 9,000/yr.

ROLLING MEADOWS, Ill., May 22 (UPI) -- Glioma, the type of brain tumor with which Sen. Edward Kennedy was diagnosed, is the most prevalent type of adult brain tumor, U.S. surgeons said.

The American Association of Neurological Surgeons said that a brain tumor is an abnormal mass of tissue in which cells grow and multiply uncontrollably, seemingly unchecked by the mechanisms that control normal cells.

It is estimated that in 2005, there were a total of 18,500 new cases of brain and other nervous system tumors diagnosed -- 10,620 males and 7,880 females. The estimated number of deaths was 12,760, of which 7,280 were males and 5,480 were females.

Brain tumors -- whether primary or metastatic, benign or malignant -- are usually treated with surgery, radiation, and/or chemotherapy, alone or in various combinations. Gliomas, which affect some 9,000 a year, can present a challenge for complete surgical removal because they have roots and tentacles. While radiation and chemotherapy are more often used for malignant, residual or recurrent tumors, decisions as to what treatment to use are made on a case-by-case basis and depend on a number of factors