The frequency and population selectivity of primary tumors of the nervous system was determined for the entire population of Israel. A national tumor registry in the Ministry of Health included information on patients discharged from all hospitals in the country as well as data from autopsies and death certificates. During the 5-yr period 1961–1965, 1,354 cases were identified. The average annual incidence was 12.8 per 100,000 population. Histological verification of tumor was available for 69 per cent of the cases included in this study. Glioma was the most commonly verified tumor (27 per cent) and, in decreasing frequency, verified tumors included meningioma (17 per cent), neurofibroma (12 per cent), pituitary adenoma (5 per cent), neuroblastoma (3 per cent), hemangioma (2 per cent), craniopharyngioma (1per cent) and dermoid (1 per cent). The distribution of tumors by type within the nervous system was calculated: 3 out of 4 involved the brain and, of these, 50 per cent were in the cerebrum. Seven per cent occurred in the spinal cord and 12 per cent affected peripheral nerves. Most of the tumors were more common in males, with the exception of meningioma which showed a female preponderance. When ethnic groups in Israel were compared as regards frequency of primary nervous system tumors, the African born immigrants had the lowest average annual incidence (7.3 per 100,000 population) and European immigrants had the highest (15.6 per 100,000 population). The immigrants born in Asian countries had an intermediate rate closer to the African, whereas the Israeliborn had rates closer to the Europeans. The differences in incidence among the ethnic groups could not be attributed to an unusual predilection to tumor at a given site in the nervous system. Five-year survival rates were calculated and, in order of decreasing survival, the tumors were: craniopharyngioma and dermoid (100 per cent), pituitary adenoma (89 per cent),hemangioma (73 per cent), meningioma (62 per cent), medullloblastoma (58 per cent), neurofibroma (52 per cent), neuroblastoma (25 per cent) and glioma (21 per cent). Age distribution data were also calculated. Direct comparisons between the Israeli series and others in the literature were difficult because of differences in method of case collection and classification of tumors. However, studies in Rochester Minnesota, and in Sweden, which used a simliar method to that employed in Israel gave an average incidence close to that observed in Israel. Literature on ethnic and racial differences in tumor incidence was reviewed and the relatively constant frequency of various nervous system tumors over the last several decades was noted. The implications of epidemiologic information about nervous system tumors were discussed with reference to etiologic considerations.
Read full abstract