International patterns of cancer incidence in adolescents.

International patterns of childhood cancer incidence are well documented but equivalent information relating to adolescence is scarce. This article synthesizes international data on cancer in adolescents from population based cancer registries. Total incidence ranged from 95 to 255 per million person years in the series studied. The highest rates were in Australia and among Jews in Israel and the lowest in India and Japan. Lymphomas were the most frequent cancers in western industrialised countries of the northern hemisphere and in the Middle East, and occurred in substantial numbers in all other regions. Hodgkin lymphoma outnumbered non-Hodgkin in western industrialised countries but was relatively rare in most developing countries and in Japan. Leukaemias were the most frequent diagnostic group in India, East Asia and Latin America. Melanoma was the commonest cancer of adolescents in Australia and New Zealand and moderately frequent in many other predominantly white populations but rarely seen elsewhere. Kaposi sarcoma was the most frequent cancer in both sub-Saharan African series studied. The highest rates for nasopharyngeal carcinoma were in Algeria and Hong Kong and for liver carcinoma in Hong Kong and sub-Saharan Africa. Testicular germ cell tumours were relatively frequent in predominantly white populations. Central nervous system tumours and thyroid carcinoma were most often registered in countries with higher standard of living. Osteosarcoma was moderately frequent almost everywhere. Characteristic embryonal tumours of childhood and the most common carcinomas of adulthood were rarely seen. Only osteosarcoma, ovarian germ cell tumours and, in some populations, nasopharyngeal carcinoma have their highest incidence at age 15-19 years. Total cancer incidence was higher in adolescent males than females, but there was often a female excess in melanoma and thyroid carcinoma, and Hodgkin lymphoma was at least as frequent among females as males in several countries with relatively high incidence. More complete delineation of worldwide patterns of cancer in adolescence would be facilitated by availability of more data classified in a standard way to take account of morphology.