Red blood cell distribution width at diagnosis as a predictor factor in chronic phase-chronic myeloid leukemia patients treated with first-generation tyrosine kinase inhibitors

Abstract: BACKGROUND: Chronic myelogenous leukemia is a hematological disorder of stem cells resulting from uncontrolled and unregulated growth of myeloid cells in the bone marrow. Since the introduction of tyrosine kinase inhibitors (TKIs), therapy has dramatically improved survival in these patients. TKIs treatment targeting BCR-ABL significantly improves the prognosis of patients with chronic myelogenous leukemia. To date, the validity of scoring systems is insufficient for predicting prognosis, and there are few studies of scoring systems for predicting treatment response and clinical efficacy of TKIs. OBJECTIVES: The objective of this study was to evaluate the ability of the red blood cell distribution width (RDW) to predict treatment response in chronic myeloid leukemia-chronic phase (CP) patients treated with first-generation TKI. PATIENTS AND METHODS: A prospective and retroprospective cohort study was conducted on chronic myeloid leukemia-CP patients treated with first-generation TKI at Iraqi Hematological Centers. The collection period was from December 2020 to November 2021. Patients were treated with first-generation TKIs as initial therapy and were followed up to assess the response by polymerase chain reaction (PCR). The assessment of RDW was done at baseline and then at 3, 6, 12, and 18 months after initiation of therapy. RESULTS: There were 150 patients included in this study. The mean age of patients was 43.7 ± 14 years (range: 18–84 years). Males were representing 48.6% and females 51.3%. The classification of baseline RDW showed that the majority of patients (53%) had high RDW. The RDW showed significant change over time, in which, it was significantly decreasing over time ( P < 0.05). Association between PCR over time and baseline RDW category showed that the high baseline RDW was associated with higher mean PCR at 3, 6, 12, and 18 months ( P < 0.05). The correlation between RDW at baseline and PCR at 3, 6, 12, and 18 months showed that there was a significant positive weak correlation between baseline RDW and PCR at 6, 12, and 18 months. The association between baseline RDW and the response showed that high baseline RDW was associated with higher failure rate at 6 and 12 months ( P < 0.05). CONCLUSION: RDW could be used in the prediction of response to treatment. Furthermore, high RDW showed significant association with high disease activity score, high white blood cell count, and lower hemoglobin, in addition to association and correlation with PCR level.