Temporal trends in the incidence of childhood leukemia, lymphomas and solid tumors in north-west Italy, 1967-2001. A report of the Childhood Cancer Registry of Piedmont

Background and Objectives. Several studies have been published on trends in childhood cancer incidence, with different patterns being reported. We present an analysis of cancer incidence trends in Piedmont (Italy) in 1967-2001 for the major categories of childhood malignant neoplasms. Design and Methods. The population-based Childhood Cancer Registry of Piedmont has recorded incident cases of malignant neoplasm in children (age 0-14) since 1967. Procedures for data collection and coding have been uniform throughout the study period. We calculated incidence rates per million children per year by sex and age-group. Trends were estimated using Poisson regression analysis, adjusted for age and sex and presented as the annual percent change (APC). Results. Significant increases were observed for all malignant neoplasms combined (3360 cases, APC: 1.3%, 95% CI: 1.0% to 1.6%), leukemia (APC: 1.0%, 95% CI: 0.4% to 1.6%), central nervous system (CNS) tumors (APC of 2.3%, 95% CI: 1.6% to 3.1%) and neuroblastoma (APC: 2.3%, 95% CI: 1.0% to 3.5%). Acute lymphoblastic leukemia (APC 1.2%, 95% CI: 0.2% to 2.3%), and Acute non-lymphoblastic leukemia (APC 1.7%, 95% CI-0.6%, 4.1) both increased over time. Differences by age groups were observed for some tumor types, such as for neuroblastoma in infants (4.8% increase per year), leukemia in children aged 1-4 years (1.2%) and CNS tumors in children aged 10-14 (3.4%). Interpretations and Conclusions. Our data suggest an increasing incidence of childhood cancer in general, and specifically for leukemia, CNS tumors and neuroblastoma in Piedmont in 1967-2001. The observed trends are unlikely to be explained by random variation, changes in exhaustiveness or quality of data collection and registration.