Frequencies of BCR::ABL1 Transcripts in Patients with Chronic Myeloid Leukemia: A Meta-Analysis

Abstract

Chronic myeloid leukemia (CML) is associated with the Philadelphia chromosome and distinct BCR::ABL1 gene transcripts. We assessed the frequencies of these transcripts in Mexico, Latin America, and worldwide. We determined the prevalence of BCR::ABL1 transcripts in CML patients and intercontinental or regional variations using specialized databases and keywords. We analyzed 34 studies from 20 countries, encompassing 5795 patients. Keyword-based searches in specialized databases guided data collection. ANOVA was employed for transcript distribution analysis. The b3a2 transcript was most prevalent globally, followed by b2a2, with e1a2 being the least frequent. Interestingly, Mexico City exhibited a higher incidence of b2a2, while b3a2 predominated in the remaining country. Overall, no significant intercontinental or regional variations were observed. b3a2 was the most common BCR::ABL1 transcript worldwide, with b2a2 following closely; e1a2 was infrequent. Notably, this trend remained consistent in Mexico. Evaluating transcript frequencies holds clinical relevance for CML management. Understanding the frequency of transcript informs personalized CML treatments.

Keywords: BCR::ABL1 transcripts; b2a2; b3a2; chronic myeloid leukemia; e1a2; prevalence.

Figure 1

Distribution of frequencies of b3a2, b2a2, and e1a2 transcripts for the analyzed continents. A two-factor ANOVA was conducted, with rows representing continents and columns representing transcripts. For the row-wise ANOVA, no significant differences were found (p > 0.99), while for the column-wise ANOVA, a p-value of < 0.0001 was obtained, indicating differences between the transcripts. Significant differences were observed only between the b3a2 and e1a2 transcripts (p < 0.0001) and between the b2a2 and e1a2 transcripts (p = 0.0002). *** p < 0.001; **** p < 0.0001.

Figure 2

Histogram of frequencies of the different BCR::ABL1 transcripts in countries of the world. A two-factor ANOVA was conducted, with rows representing countries and columns representing transcripts. For the country-wise ANOVA, no significant differences were found (p > 0.999), while for the transcript-wise ANOVA, a p-value of <0.0001 was obtained. Significant differences were observed in all countries between the b3a2 and e1a2 transcripts (p < 0.0001) and between b3a2 and b2a2 transcripts (p = 0.0002), with b3a2 being the most frequent transcript. Significant differences were also found for the b2a2 transcript when compared to the e1a2 transcript (p = 0.0001). *** p < 0.001; **** p < 0.0001.

Figure 3

Histogram of frequencies of the different BCR::ABL1 transcripts in different regions of Mexico. A two-factor ANOVA was conducted, with rows representing regions and columns representing transcripts. For the regional ANOVA, no significant differences were found (p > 0.099), while for the transcript-wise ANOVA, a p-value of 0.0025 was obtained, indicating significant differences in the Tukey multiple comparison for the frequency between b3a2 and e1a2 transcripts. In the case of Guanajuato, the western region of Mexico, and Puebla, the b3a2 transcript was significantly more frequent compared to e1a2 (0.0202). In Mexico City (CDMX), the most frequent transcript was b2a2. Meanwhile, no significant differences were noted between the b3a2 and b2a2 transcripts for any of the regions analyzed. CDMX = Mexico City. * p < 0.05.