Comparison of ELTS Score with Sokal, Euro and EUTOS Scores in Risk Stratification of Patients with Chronic Myeloid Leukaemia at a Tertiary Care Hospital in Bangladesh.

Abstract

Chronic myeloid leukaemia (CML) is a common myeloproliferative neoplasm characterized by constitutional tyrosine kinase activation resulting from translocation between chromosome 9 and 22. For its treatment, second line tyrosine kinase inhibitors are often preferred ahead of first line tyrosine kinase inhibitors in patients with high-risk disease. Historically, prognostic scores - Sokal, Euro and European Treatment Outcome Study (EUTOS) scores were utilized for risk stratification. In 2016, a newer risk scoring system - European Treatment Outcome Study (EUTOS) Long Term Survival (ELTS) score was formulated. European Leukaemia Net recommended ELTS score as the preferred scoring system for CML in 2020. The study stratified CML Chronic Phase patients utilizing all four available risk scoring system. This observational study was conducted among chronic myeloid leukaemia patients at Bangabandhu Sheikh Mujib Medical University (BSMMU), Bangladesh from June 2020 to April 2021. Fifty CML patients in chronic phase were enrolled in this study using purposive sampling technique. Risk stratification was done using Sokal, Euro, EUTOS and ELTS scores. Among study participants, 14.0% were identified as high-risk cases using ELTS score. Previously used scores - Sokal score, Euro score and EUTOS score identified 32.0%, 8.0% and 10.0% cases as high-risk disease respectively. Sokal and Euro scores had moderate (kappa 0.403 and 0.469 respectively) agreement with ELTS score while EUTOS and ELTS scores had slight (kappa 0.073) agreement. ELTS score should be adopted as the preferred prognostic tool for CML patients.