Predictive Factors of Patients with Chronic Phase Chronic Myeloid Leukemia Treated with Tyrosine Kinase Inhibitor

Abstract

Background: Chronic Myeloid Leukemia (CML) is a hematological malignancy caused by an abnormality of the Philadelphia chromosome. Along with the development of CML treatment, the discovery of tyrosine kinase inhibitors (TKI) paved the way for CML patient and lead to longer survival rate. It is very important to know whether the treatment response is successful or not as well as the predictive factors that can improve the therapeutic response of CML patients treated with TKI.

Methods: This study is an observational cohort study conducted for 12 months long and involving 40 CML patients treated with TKI, both hematological and molecular therapy response were evaluated in this study. We analyzed some predictive factors such as relationship between early clinical and laboratory symptoms before the treatment by TKI and treatment response and the relationship between Eutos, Sokal and Hasford scores and treatment response.

Results: A total of 40 chronic phase CML patients, consist of 25 men (62.5%) and 15 women (37.5%) with mean age of 37 years. Most common clinical manifestation was weight loss (100%), followed by splenomegaly in 39 people (97.5%). Complete Hematologic Response (CHR) after 3 months of TKI therapy was achieved by 15 patients (37.5%). The number of patients who achieved 6-months CHR increased to 19 patients (47.5%). Among 37 samples who performed quantitative examination on fusion of the breakpoint cluster region (BCR) gene on chromosome 22 gene in band q11 and Abelson murine leukemia (ABL1) gene on chromosome 9 band q34 (BCR-ABL), 20 patients (54%) achieved major molecular response (MMR), and the remaining 17 (45.9%) had not yet achieved MMR. We found significant relationship between basophils and quantitative BCR-ABL levels (p < 0.01). We didn't find any relationships between these three scores (Eutos, Sokal and Hasford) with treatment response, both hematological and molecular treatment response.

Conclusions: The prevalence of CHR at 3 months was 37.5% meanwhile prevalence of MMR after 12 months was 54%. We found that basophil percent at 3 months after treatment is predictive factor and significantly associated with quantitative BCR-ABL levels (p < 0.05).