Temporal changes in survival among adult patients with acute lymphoblastic leukaemia diagnosed in the period 1998-2020 – A Danish nationwide population-based cohort study

BACKGROUND: Previous studies have shown continuous improved overall survival (OS) up to 2015 for young adults with acute lymphoblastic leukaemia (ALL). However, recently several important advances have been made justifying a more contemporary analysis of outcomes in adult with ALL. METHODS: In this nationwide population-based cohort study, we included patients above 18 years of age diagnosed with ALL between January 1, 1998, and December 31, 2020. Patients were followed until December 31, 2022. By employing flexible parametric survival models, we quantified progress in OS using the key endpoint of 2-year age standardized OS for all patients and clinical subgroups of interest. FINDINGS: This study includes 657 patients and demonstrates a significant improvement in OS over time with the 2-year age standardized OS increasing from 36·4 % (95 % CI, 27·0-45·8 %) for patients diagnosed in 1998 to 68·6 % (95 % CI, 60·2-76·9)for patients diagnosed in 2020, corresponding to an absolute increase in 2-year OS of 32·2 % points (95 % CI, 19·1-45·2). Stratified analysis revealed improvements for both Philadelphia chromosome positive and negative ALL, across cytogenetic risk groups, and for B- and T-cell ALL, whereas the latter did not reach statistical significance. Improvements were seen across all ages; however, most pronounced for Philadelphia chromosome positive ALL and patients below 60 years of age. INTERPRETATION: These results show a universal and continuous improvement in the treatment of adult ALL. Currently, novel treatment combination and advances in cellular therapy occur rapidly, and we expect even further improvements in the years to come. FUNDING: Northern Region of Denmark.