Prognostic significance of B-cell lymphoma 2 expression in acute leukemia: A systematic review and meta-analysis

Abstract

A number of studies have provided estimates of the correlation between B-cell lymphoma 2 (Bcl-2) expression and its clinical significance in acute leukemia (AL); however, the results have been heterogeneous. In order to clarify the prognostic significance of Bcl-2 status in patients with AL, a systematic review and meta-analysis of 5 published studies including a total of 665 subjects was performed. The reported frequency of Bcl-2 expression was 0-99.00%. Bcl-2-positive patients had a higher median white blood cell count compared to Bcl-2-negative patients. Additionally, Bcl-2-negative patients had >2-fold higher odds of achieving complete remission (CR) compared to Bcl-2-positive patients. The summary hazard ratio of Bcl-2 negativity/positivity for CR was 0.62 [95% confidence interval: 0.53-0.81, P<0.001]. Although this meta-analysis was based on data abstracted from observational studies, our results may justify the use of risk-adapted therapeutic strategies for AL according to the Bcl-2 expression status.

Keywords: B-cell lymphoma 2 protein; acute leukemia; clinical significance; meta-analysis.

Figure 1.

Flow diagram of the study selection process.

Figure 2.

Forest plots of the hazard ratio (HR) for complete remission. The size of the blocks or diamonds reflects the weight for the random-effects model in the meta-analysis. HR <1 indicates that the negative expression of Bcl-2 was associated with a better prognosis. Bcl-2, B-cell lymphoma 2; WBC, white blood cell.

Figure 3.

Funnel plot of the hazard ratio for complete remission. SE (MD), standard error of the mean difference.