1967 - 2001 . A report of the Childhood Cancer Registry

In the last few decades several studies have examined temporal trends in the incidence of childhood cancer in various Western countries. These reports have focused mainly on leukemia brain tumors, and to a lesser extent on rarer childhood neoplasms. The findings are not consistent, with differing patterns for different cancer sites and in different countries. Several papers have reported an increase in childhood leukemia or in some leukemia subtypes, whereas others have found no significant trends or have reported stable rates. A more complex pattern was reported by the SEER working group. Ries et al. reported a significant annual percent increase for leukemia (all types combined) of 0.7% from 1975 to 2001; the increases primarily occurred during 1975-1986 (annual percent change: +1.5%), whereas in 19872001 the trend was weaker and not statistically significant (+0.3%). The patterns are more consistent for brain tumors and for neuroblastoma with most studies reporting significant increases over time. However, it is not clear whether improvements in diagnostic procedures account for the observed trends or whether a genuine increase in incidence has occurred. Only a few studies have examined other types of childhood cancer and the findings have been inconsistent, possibly because of the small number of cases involved. The Childhood Cancer Registry of Piedmont (CCRP) is the oldest and largest pediatric population-based Cancer Registry active in Italy. Data are available over a 35-year period, from 1967 to 2001. In a previous report we described inciChildhood Cancer Registry of Piedmont, Cancer Epidemiology Unit, CPO Piemonte, CeRMS, S. Giovanni Hospital and University of Turin (PD, GP, LZ, MMM, NP, FM, CM); Medical Statistics Unit, Department of Public Health and Microbiology, University of Turin (PD); Division of Pediatrics, Dept. of Medical Sciences of the University of Eastern Piedmont, Novara (GP); Center for Public Health Research, Massey University Wellington Campus, New Zealand (NP); Unit of Medical Statistics and Epidemiology, CPO Piemonte and Department of Medical Sciences of the University of Eastern Piedmont, Novara (CM), Italy.