The prognostic value of CD2, CD4, and HLA-DR expression and FLT3-ITD mutation in adult acute promyelocytic leukemia

Negative expression of CD117 predicted inferior OS and PFS in acute promyelocytic leukemia

INTRODUCTION

In recent years, the correlation between CD117 antigen and the prognosis of hematological malignancies has been demonstrated. However, there is limited literature on the clinical significance of CD117 antigen in acute promyelocytic leukemia (APL). The aim of this study was to retrospectively analyze the clinical features and prognostic significance of CD117 in APL.

METHODS

In this study, we retrospectively investigated the clinicopathological characteristics, outcome, and prognostic impact of negative CD117 expression (CD117-) in 169 APL patients treated with all-trans retinoic acid (ATRA) and arsenic trioxide (ATO) containing regimen.

RESULTS

The median follow-up period was 63.0 months. CD117- was detected in 13 APL patients (7.7%). No significant differences were found in baseline characteristics between CD117+ and CD117- subgroups. However, compared to CD117+ APL, the incidence of early death (ED) was significantly higher in CD117- APL (p = 0.023). By multivariate analysis, CD117- was an independent adverse prognostic factor for overall survival (OS) and progression-free survival (PFS) (p = 0.022 and p = 0.014, respectively).

CONCLUSIONS

To sum up, CD117- is associated with greater risk of ED and has the statistical power to predict inferior OS and PFS, this marker may be considered to build prognostic scores for risk-adapted therapeutic strategies in APL management.

Acute promyelocytic leukemia with PML/RARA (bcr1, bcr2 and bcr3) transcripts in a pediatric patient

Patients with acute promyelocytic leukemia (APL) exhibit the t(15;17)(q24.1;q21.2) translocation that produces the promyelocytic leukemia (PML)/retinoic acid receptor α (RARA) fusion gene. Different PML breakpoints yield three alternative molecular transcripts, bcr1, bcr2 and bcr3. The present study reports the simultaneous presence of three PML/RARA transcripts in a pediatric female patient diagnosed with APL, according to the clinical characteristics, immunophenotype and karyotype of the patient. The simultaneous presence of the PML/RARA transcripts were detected using reverse transcription-quantitative PCR (RT-qPCR). This was confirmed with HemaVision-28N Multiplex RT-qPCR, HemaVision-28Q qualitative RT-qPCR and the AmpliSeq RNA Myeloid Panel. To the best of our knowledge, the pediatric patient described in the present study is the first case found to exhibit all three PML/RARA transcripts (bcr1, bcr2 and bcr3). Additionally, a microarray analysis was performed to determine the expression profile, potential predictive biomarkers and the implications of this uncommon finding. According to the information obtained from molecular monitoring, the results reported in the present study were associated with a good patient prognosis. In addition, upregulated genes that are rare in acute myeloid leukemia were identified, and these genes may be promising diagnostic biomarkers for further study. For example, CCL-1 is present in leukemic stem cells, causing treatment failure and relapse, and α- and β-defensins have been reported exclusively in chronic myeloid leukemia. However, the results of the present study confirmed that they may also be present in APL. Thus, these findings suggested a possible signaling pathway that involves the PML/RARA oncoprotein in APL.

All-trans Retinoic Acid, Arsenic Trioxide, and Anthracycline-based Chemotherapy Improves Outcome in Newly Diagnosed Acute Promyelocytic Leukemia Regardless of FLT3-ITD Mutation Status

All-trans retinoic acid (ATRA) and pre-upfront arsenic trioxide (ATO) have revolutionized the therapy of acute promyelocytic leukemia (APL). However, internal tandem duplication of FMS-like tyrosine kinase 3 (FLT3-ITD) mutations is associated with increased risk of relapse. The aim of this study was to analyze the prognostic impact of FLT3-ITD on APL patients who received remission induction with ATRA, idarubicin (IDA) and/or ATO, followed by ATRA plus ATO along with anthracycline, as consolidation therapy. A total of 72 patients newly diagnosed with APL were included in this study. 83.3% of the patients achieved complete remission (CR) after induction therapy. FLT3-ITD mutations were detected in 16 (22.2%) patients and closely related to bcr-3 PML-RARa transcript (P<0.001). The 5-year overall survival (OS) rate was 100% in both FLT3-ITD^positive and FLT3-ITD^negative groups, and there was no significant difference in 5-year event-free survival (EFS) between the two groups (78.3% vs. 83.3%, P=0.85). ATRA plus ATO and anthracycline-based chemotherapy achieved great outcome in newly diagnosed APL regardless of the FLT3-ITD mutation status.