INCREASING INCIDENCE OF CHILDHOOD-CANCER - RESORT OF 20 YEARS EXPERIENCE FROM THE GREATER DELAWARE VALLEY PEDIATRIC TUMOR REGISTRY

As little is known about the aetiology of cancer in children, analysis of time trends may be useful. Recent data on time trends for paediatr ic cancers are very limited. We report here on trends in the incidence of 15 categories of cancer in children under 15 years of age from 197 0 to 1989, using data from the Greater Delaware Valley Pediatric Tumor Registry in the US. Total cancer incidence increased 1% per year (P < 0.001). Neither acute lymphocytic leukaemia, acute myelocytic leukaem ia, nor total leukaemia incidence changed significantly. In contrast, the incidence of central nervous system (CNS) tumours rose 2.7% per ye ar (P < 0.001). All three subgroups of this category, glioma, primitiv e neuroectodermal tumour (PNET)/medulloblastoma, and other CNS tumours , showed increases. For glioma and PNET/medulloblastoma, trends differ ed by age, race, and/or gender. Among the other childhood cancers, sig nificant increases were observed for non-Hodgkin lymphoma and neurobla stoma. For osteosarcoma and retinoblastoma, no overall change in incid ence was observed, although decreases were observed in some age and ra ce subgroups. The rise in CNS tumour incidence confirms previous repor ts from the US and Great Britain. The lack of change for acute lymphoc ytic leukaemia conflicts with other data from the US, but diagnostic c hanges appear to explain at least part of the discrepancy. The increas e in neuroblastoma has also been observed in Great Britain. In contras t to our finding, investigators in the US and Great Britain have repor ted no rise in non-Hodgkin lymphoma. Analyses for more of the childhoo d cancers from other registries would aid in detecting and interpretin g incidence trends in recent years.