The Effect of BCR-ABL(IS) Levels on Early and Late-Stage Response Rates and Prognosis at the Time of Diagnosis in Patients with Chronic Myeloid Leukemia (CML) in Chronic Phase

Abstract

Objective: The BCR-ABL(IS) value plays a crucial role in the prognosis of chronic myeloid leukemia (CML) patients. The aim of this study was to compare molecular response rates two BCR-ABL(IS) score levels at the time of diagnosis in chronic-phase CML patients.
Methods: The study included 104 patients diagnosed with chronic-phase CML at the Hematology Clinic of Dicle University Faculty of Medicine. BCR-ABL(IS) values were measured during the course of the patients' treatment, with a median follow-up period of 42 months. Molecular response rates were assessed at the 3rd, 6th, and 12th months, and long-term follow-up was conducted to evaluate the effect of BCR-ABL(IS) values at diagnosis on patient outcomes.
Results: Patients were divided into two groups based on their BCR-ABL(IS) values at diagnosis: 52 patients (50%) had BCR-ABL(IS) values below 75% (median BCR-ABL(IS) = 56.3%), and 52 patients (50%) had BCR-ABL(IS) values above 75% (median BCR-ABL(IS) = 111%). No significant difference was observed between the early (3rd and 6th months) and late (12th month and long-term) optimal response rates between the two groups. Both groups showed similar responses at these time points, indicating that the initial BCR-ABL(IS) value did not significantly impact the response rates or prognosis at the 3rd, 6th, and 12th months, in the long-term follow-up.
Conclusions: The prognosis of CML patients is influenced by various factors at diagnosis, including patient characteristics and disease factors. However, our study found that the BCR-ABL(IS) value at the time of diagnosis is not a predictive factor for prognosis.

Keywords

• Chronic Myeloid Leukemia(CML)
• BCR-ABL(IS)
• Prognosis

Project Number

177

Ethical Statement

This retrospective study was conducted with the approval of the Dicle University Faculty of Medicine Ethics Committee for Noninterventional Studies (decision date: 15.04.2026, decision no: 177).

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