Population-based analysis of survival after childhood cancer diagnosed during 1970-1998: 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 centralm 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 >50,000×10⁶ 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.