Incidence of malignant disease by morphological type, in young persons aged 12-24 years in England, 1979-1997.

Cancer incidence data are generally presented in terms of primary site, but this method is inappropriate for cancers in young persons. We have used a morphology-based classification system to produce national incidence rates for cancers in persons aged 12-24 years by detailed diagnostic sub-type. The overall incidence rates for malignant disease in young persons aged 12-14, 15-19 and 20-24 years were 10.1, 14.4 and 22.6 per 100000 population, respectively. The three most frequent cancer types in 12-14-year-olds were leukaemias, lymphomas and central nervous system (CNS) tumours. In 15-19-year-olds, lymphomas were most frequent and leukaemias second with carcinomas third. In 20-24-year-olds, lymphomas were again most frequent, but carcinomas and germ cell tumours were second and third. There was also variation with age in the ratios of rates in males and females. These changing incidence patterns have aetiological implications and provide clues for future hypothesis-based research.