THE ETHNIC DISTRIBUTION OF PRIMARY CENTRAL NERVOUS SYSTEM TUMORS: AFIP, 1958 TO 1970

A retrospective ethnic study was made of 16,311 cases of primary central nervous system (CNS) tumors seen at the Armed Forces Institute of Pathology (AFIP), Washington, D.C, from 1958 to 1970. Results showed a considerably higher Caucasian:Negro (C:N) case ratio (13.7:1) than the C:N population ratio (8.4:1), indicating a higher relative frequency of primary CNS tumors in American Caucasians as compared to American Negroes. The glioma was significantly more frequent in Caucasians than in Negroes (p < 0.005). In contrast, Negroes had an excess of the pituitary adenoma as compared to Caucasians (p < 0.01). The proportional frequencies of the meningioma and the nerve sheath tumor were also higher in Negroes than in Caucasians. When this pattern of the tumor distribution of American Negroes was compared to that of African Negroes (a composite African series), the preponderance of the pituitary adenoma and the meningioma and the relative paucity of the glioma in the Negro race as compared to Caucasians were again confirmed. The differences in the relative frequency and the tumor distribution between American Negroes and Caucasians and the considerable similarity of the tumor distribution between American and African Negroes emphasize the importance of genetic factors in the development of at least some primary CNS tumors.