Longitudinal changes in transfusion practice in myelodysplastic syndromes (mds): a population data-linkage study.

Abstract

Background: In recent years, MDS disease-modifying therapies (DMTs) which aim to slow disease progression and reduce transfusion burden, have become widely available. However, real-world data on transfusion needs in MDS patients and the impacts of DMTs, is sparse. In Australia, from 2011, 5-azacitidine became the first funded DMT for patients with IPSS classification intermed-2 or high-risk MDS and chronicmyelomonocytic leukaemia-2 (CMML2). National patient blood management (PBM) guidelines were also published in 2011. Aim(s): To describe red blood cell transfusion (RBC-T) and platelet transfusion (PLT-T) burden in MDS/CMML patients admitted to Victorian hospitals over 14 yrs, and explore whether transfusions were impacted by introduction of DMTs and PBM guidelines. Method(s): Retrospective longitudinal cohort study of all MDS/CMML patients admitted to Victorian hospitals from 2009-2022, using data linkage from hospital admissions dataset (contains all public and private hospital admission data), cancer and death registries. We used the mean cumulative function to estimate the average number of transfusion episodes per patient by a given time, and compared by MDS subtype, year of MDS diagnosis and whether admissions were 'pre' vs 'post' 2011. MDS subtypes were defined as those in the International Statistical Classification of Diseases and Related Health Problems, 10th Revision Australian Modification (ICD-10-AM), which is used in the datasets for all diagnoses and hospital procedures. Result(s): 7043 patients (5715 with MDS; 1328 with CMML) were reported to the cancer registry. The cohort was elderly (> 50% aged >= 75y), predominantly male (61%). Median follow-up was 1.9 years (IQR 0.6-4.1 years). 53% of patients died (median overall survival 3.6 years (95% CI 3.4-3.8)). In total, the cohort had 55,048 RBC-T and 10,749 PLT-T admissions. By 1yr post-diagnosis, an MDS patient had on average 3.6 RBC-T and 0.9 PLT-T admissions, increasing to 14 RBC-T and 2.7 PLT-T by 5 yrs. Disease subtype significantly impacted transfusions (Table 1). Patients with RARS and RAEB had the most RBC-T admissions (22.4 and 20.8 by 5yrs). PLT-T admissions were highest for patients with RAEB (6.7 by 5yrs). PLT-T were significantly higher post-2011 vs pre-2011 (0.8 more PLT-T admissions by 2 yrs, p < 0.001) but there was no difference in RBC-T admissions. MDS diagnosis year did not affect transfusion admissions. Summary/Conclusions: By 5 yrs post diagnosis, patients have an average of 14 RBC-T and 3 PLT-T admissions, with transfusion burden significantly affected by MDS subtype. Since 2011, PLT-Ts for MDS/CMML have increased despite PBM guidelines recommending against regular PLT-T in MDS; this may be due to the increased use of DMTs and their potential impacts on thrombocytopenia and/or clinicians choosing to administer PLT-T due to lack of other effective treatments for thrombocytopenia. Given the costs and limited supply of PLT products, our findings have implications for national blood supply planning and also highlight the need for research to optimise PLT-T in these patients. Acknowledgements: Victorian Department of Health for datasets.