Population-based survival after childhood lymphoblastic leukaemia in time periods corresponding to specific clinical trials from 1979 to 1998--a report from the Childhood Cancer Registry of Piedmont (Italy).

This study evaluated the outcome after childhood acute lymphoblastic leukaemia (ALL) in a population aged 0-14 years served by the Childhood Cancer Registry of Piedmont (CCRP) during the accrual periods to nationwide clinical studies run by the Italian Association for Paediatric Haematology and Oncology (AIEOP). In the time period considered (March 1979-December 1998) the CCRP recorded 498 incident cases of ALL. The living status on 31 December 2000 was known for 497 cases. Overall survival at 5 years was 74.1% standard error (S.E.) 2.0%). It increased from 58.6% (S.E. 4.9%) for cases diagnosed in March 1979-July 1982 to 87.3 (S.E. 3.6) in May 1995-December 1998. Results observed from data in our population-based study in Piedmont were similar to those presented in the nationwide clinical trials. Survival was better (statistically significant) for children aged 1-4 years, with a white blood cell (WBC) count lower than 10 000 x 10(3) cells/litre and for B-precursor ALL. Differences by immunophenotype were statistically significant only in the univariate analyses. Girls showed a non-statistically significant survival advantage over boys. Results of the present study show the impact on the population of recent clinical trials and emphasise the role of population-based cancer registries in evaluating childhood cancer care delivery in a given population.