Sixty-five years of progress in outcomes of acute lymphoblastic leukaemia in children in Kujavian-Pomoranian region of Poland

Background: The first report on children treated for acute leukemia in Bydgoszcz (Poland) comes from 1958: eleven children were treated with steroids and blood transfusions. Objective: Analysis of results of treatment of children with ALL between 1958–2023 in a single-center study in Poland. Material and methods: A total number of 809 children were included in the study: 215 children treated with various drugs between 1958–1972; 56 children treated with Total Therapy protocols V–VII (St. Jude, Memphis) between 1976–1983; 33 children treated according to BFM-83; 81 children treated according to NOPHO-86 between 1988– –1995; 115 children treated with BFM-90 or New York I/II protocols between 1995–2002; 115 children treated with ALL-IC-2002 between 2002–2011; 95 children treated with ALL-IC-2009 between 2011–2018; and 99 children treated between 2018–2023 with a new international protocol. Results: In respective periods, the following 10-year probabilities of overall survival (pOS) were obtained: p = 0.012 ± 0.008 (1958–1972); p = 0.143 ± 0.047 (1976–1983); p = 0.485 ± 0.087 (1983–1988); p = 0.543 ± 0.055 (1988–1995); p = 0.731 ± 0.042 (1995–2002); p = 0.791 ± 0.038 (2002–2011); p = 0.915 ± 0.021 (2011–2018); and p = 0.962 ± 0.024 (2018–2023) (p <0.0001). After adjustment for the time period, in univariate Cox analysis, in comparison to 2018–2023, the hazard risk (HR) of death was: HR = 2.4 for patients treated between 2011–2018; HR = 5.2 (2002–2011); HR = 6.3 (1995–2002); HR = 12.7 (1988–1995); HR = 13.6 (1983–1988); HR = 38.0 (1976–1983); and HR = 52.4 (1958–1972) (p <0.0001). The hazard risk of leukemic relapse was: HR = 1.9 for patients treated between 2011–2018; HR = 7.6 (2002–2011); HR = 10.4 (1995–2002); HR = 19.9 (1988–1995); HR = 15.9 (1983–1988); HR = 26.0 (1976–1983); and HR = 75.0 (1958–1972) (p <0.0001). The hazard risk of any event was: HR = 1.4 for patients treated between 2011–2018; HR = 4.4 (2002–2011); HR = 4.9 (1995–2002); HR = 8.4 (1988–1995); HR = 8.7 (1983–1988); HR = 18.5 (1976–1983); and HR = 33.4 (1958–1972) (p <0.0001). Conclusions: Complex management of children with ALL based on therapy of international strategy of multidrug chemotherapy and multidirectional supportive therapy has enabled to increase longterm survival from 1% in 1960s to 96% in 2023.