Unusual distribution of childhood cancer in Namibia.

A survey of childhood cancer was undertaken in Namibia from 1983 to 1988 to record all tumors in children less than 15 years of age. The national incidence of childhood cancer in the republic of Namibia was 55.5 per million children. The overall incidence rate was 73.3 per million in urban and densely populated areas, and 44.4 per million in the rural areas. This difference was not statistically significant. The relatively high 75 per million overall incidence of tumors amongst the white population group was probably due to the generally higher socioeconomic status and concomitant good medical care of this ethnic group during the study period. The significantly higher overall incidence of tumors (109 per million) recorded in the Rehoboth ethnic group, however, could not be accounted for by socioeconomic status or better health care facilities and remains unexplained. The cause of the increased incidence of central nervous system tumors in the Herero (26 per million) and osteosarcomas in the Kavango (11 per million) ethnic groups is also not clear and warrants further research. The apparent geographical cluster of tumors in northern and central Namibia was caused by the irregular distribution of the population.