Does BCR-ABL transcript type influence the prognosis of patients in chronic myelogenous leukemia chronic phase?

Abstract

Introduction and objective In this study, we evaluated the influence of the transcript type on hematological and clinical parameters, as well as the event-free survival of 50 patients in the Chronic myeloid leukemia chronic phase. Methods We reviewed the medical records of 55 patients with Chronic myeloid leukemia. The eligibility criteria were based on the availability of hematological and clinical baseline data in the medical records. Data on BCR-ABL transcripts were obtained from medical records. Results Eighteen patients (36%) had the b2a2 transcript, 24 (48%) had b3a2 and 8 (16%) had b2a2/b3a2 . The median platelet count for transcripts b2a2 , b3a2 and b2a2/b3a2 was 320.65 × 10 3 /L, 396 × 10 3 /L, and 327.05 × 10 3 /L, respectively ( p = 0.896). We could not find any differences in relation to the other hematological parameters, when compared to the transcript type. Comparison between spleen and liver size and type of transcript did not differ inside the groups ( p = 0.395 and p = 0.647, respectively) and the association between risk scores and transcript type did not show statistical significance ( p > 0.05). The 21-month probability for event-free survival was 21%, 48% and 66% for the transcripts b2a2 , b3a2 and b2a2/b3a2 respectively ( p = 0.226) Conclusion We conclude that the expression BCR-ABL transcripts have no influence on hematological, clinical and event-free survival parameters of patients in the Chronic myeloid leukemia chronic phase.

Characteristics of BCR–ABL gene variants in patients of chronic myeloid leukemia

“…Few studies have also documented higher frequency of e13a2 compared to more common e14a2 transcript in CML patients [ 31 , 32 , 33 ]. The variation in frequencies of common transcript among different population and regions of the world can be explained based on the dissimilarities of natural genetic factors, environmental factors, and living style in different ethnic groups [ 34 ].…”

“…Varying results from all over the world have been reported regarding the co-expression of both transcripts e13a2 and e14a2 in patients with CML. Incidence of this co expression has been reported to be as high as 16% in a study from Brazil [ 34 ]. However, in our local population, the frequency of co-expression was reported to be very low, which is in agreement to the result of the present study [ 25 , 33 ].…”

“…Higher platelets count in patients with e14a2 transcript was also observed in this study, but the difference was not found to be statistically significant. Few other studies reported no differences in hematological parameters in both transcripts of BCR–ABL fusion gene [ 25 , 34 , 35 ].…”

“…It is also believed that the type of transcript alone is not responsible for differences between the clinical and hematological parameters, and there must be some other factors that modify these parameters [ 34 ]. European Leukemia Net recommendations do not give any caution to patients with different transcripts and suggest that these variant translocations do not affect the prognosis of CML patients [ 16 ].…”

Złożona translokacja wariantowa t(9;22;6;17;1) w przebiegu leczenia przypadku przewlekłej białaczki szpikowej.

“…It is generally believed that the imatinib treatment failure in patients with chronic CML is most often caused by the presence of the BCR-ABL1 oncogene mutation [18]. Attempts to demonstrate the impact of BCR-ABL1 transcript on the treatment results did not show any significant differences in this respect, although it was demonstrated that patients with b2a2 transcript had a higher event-free survival (EFS) [18,19].…”