Cancers of the brain and central nervous system were reported diagnosed in 160 persons in the SRRHIS region from 1991 through 1993. Incidence rates for whites of both sexes are higher than for blacks, and the rate for black females was much lower than for other groups (Figure 4). Although nationally the incidence rate for white males is higher than for white females, in this population they are similar with white females showing a rate of 5.8 per 100,000 compared to white males at 5.7 (SEER white females 5.8; white males 8.2).

Among black residents of the SRRHIS area, the incidence rate for black males was 4.4 per 100,000, similar to the SEER rate of 4.2. Black females however, showed a remarkably low rate of 1.7 compared to the SEER rate of 3.1.

Risk factors for brain and other nervous system cancers are not well understood or identified. Potential risk factors include exposures to ionizing radiation, organic solvents, pesticides, and electromagnetic fields, but the true risks in both occupational settings and the general population remain poorly defined.

Incidence and mortality rates have been increasing nationally over the last two decades, partly due to the development of noninvasive imaging techniques such as Computerized Axial Tomography and Nuclear Magnetic Resonance Imaging which can provide more accurate diagnosis without surgical intervention (Miller, 93). Also the availability of better medical care for elderly persons since the advent of Medicare has allowed more accurate discrimination of brain cancers from similar symptoms for stroke or other degenerative diseases.

Five year relative survival rates for brain cancers in adults are poor regardless of stage. The survival rate for all stages is 29%, for localized tumors 33%. However, for children younger than 20 at diagnosis, five year relative survival rates are 63% (Kosary, 95).