Childhood leukaemia in North West England 1954-1977: epidemiology, incidence and survival.

The annual incidence of leukaemia among children aged up to 14 years as estimated by the Manchester Children's Tumour Registry has been analysed for the 24 years 1954-1977. A significant increase in acute lymphoid leukaemia (ALL) was found, while the incidence of acute myeloid leukaemia (AML) remained constant. Other types of leukaemia were too rare to be analysed separately. The increase in ALL was concentrated among boys in the 1--5-year age group. Analysis with respect to initial white-cell count showed the increase to be more pronounced in children with initial white cell counts of 1-5 x 10(4)/microliters. The proportion of cases presenting in Lancashire compared with Greater Manchester did not change during the study period. The distribution of cases with respect to social class and socio-economic group of the parents also remained constant. Due to advances in the treatment of childhood ALL survival improved considerably during the study period and no increase in mortality was seen.