CHILDHOOD-CANCER INCIDENCE IN ZARAGOZA AND NAVARRE (SPAIN) - 1973-1987

Patterns and trends in childhood cancer incidence for Navarre and Zara goza registries were studied over the 15-year period, 1973-1987. Overa ll cancer rates and rates for 10 specific types of cancer were analyse d using a log-linear Poisson model or, alternatively, a gamma-Poisson model whenever overdispersion was present, with age, sex, registry and period being used as predictor variables. Childhood cancer was 30% mo re frequent in boys than in girls, and, except for lymphomas and bone tumours, incidence decreased remarkably with age. Adjusted rates were high in comparison with other European countries, particularly in the case of non-Hodgkin's lymphomas. Cancer rates proved somewhat higher i n Navarre, but this difference attained statistical significance solel y in the case of central nervous system tumours (rate ratio = 1.75; 95 % confidence interval 1.21-2.54). A significant rise in overall incide nce was observed (11% 5-yearly increase) due mainly to the upward tren d in central nervous system tumours. While the rise in these tumours c oincides with the period which witnessed the spread of computerised to mography in Spain, the trend nevertheless held steady over the last 5- year period, when access to this diagnostic technique had already beco me generalised nationwide. (C) 1997 Elsevier Science Ltd.