Population-based survival after childhood cancer diagnosed during 1970-98: a report from the Childhood Cancer Registry of Piedmont, Italy.

BACKGROUND AND OBJECTIVES: Survival after childhood cancer has shown a steady improvement from the late 1970s in most developed countries. Since 1967 the Childhood Cancer Registry of Piedmont has been collecting cases of malignant tumor, diagnosed in children aged 0-14 years, living in Piedmont. This work aims to update survival rates to 31.12.2000. DESIGN AND METHODS: This study includes 2,678 children diagnosed between 1970-98. Vital status was assessed at the Registry Office of the town of residence. One thousand four-hundred ninety cases were reported to be alive, 1170 dead and for 18 the status was unknown. Thirty-three cases registered with a death certificate only were excluded. Completeness of follow-up was 99.3%. All tumor types were classified according to the Birch-Marsden classification. Histologic verification was available for 94.4% of cases. RESULTS: Survival at 5 years increased over the period 1970-98 for all tumor types with a statistically significant trend over time (p<0.0001). The 5 year survival rate for acute lymphoblastic leukemia (ALL) increased steadily from 24.7% (95%CI 15.0-34.3) to 87.6% (80.9-94.3), for acute non-lymphoblastic leukemia (ANLL) from 0.0% to 38.1% (17.3-58.9), and for non-Hodgkin's lymphomas from 25.2% (0.6-49.8) to 79.7% (61.9-97.5). Five year survival rates of children with central nervous system tumors increased from 33.4% in 1970-74 to 78.5% in 1990-94 and decreased in 1995-98 to 70.9%. Age <1 year and >50,000x10(6) cells/L at diagnosis were negative prognostic factors for ALL. Age <1 year was a favorable prognostic factor for neuroblastoma. INTERPRETATION AND CONCLUSIONS: Survival of children with all types of tumors improved in Piedmont. This improved survival is comparable to that reported by other European and North American population-based cancer registries.