[Descriptive epidemiology of malignant tumors in children]

The object of this study is to present the descriptive epidemiology of cancer in children at the world and national levels. The international and national literature published on cancer in children was comprehensively reviewed, with emphasis on reports treating epidemiological aspects of time, place and person. For practical reasons and with the aim of integrating the information, only the more relevant publications were included. Incidence and child mortality were analyzed. Overall incidence is between 100 and 150 (annual rates = cases x 10(6) children). Specific incidence varies according to the type of cancer, the region and the country. The Latin American pattern of neoplasms is constituted by leukemias, lymphomas, and central nervous system tumors (CNST); in the Northamerican/European pattern the CNST appear in second place and in the African pattern, lymphomas show predominance. Incidence is higher among the younger than 5 year olds, from urban environments, and there is a 1% annual increase of cancer in Northamerican children. Child mortality has diminished remarkably, mainly in developed countries, whereas in developing or underdeveloped countries, incidence remains stable or shows a slight fall. The incidence of cancer in children is greater in developed countries, but in underdeveloped countries it may be underestimated. These countries have not managed to reduce the incidence of child mortality caused by cancer, as have the United States or Great Britain. Further studies on the epidemiology of cancer in children are necessary, since many data remain unknown.