How to Improve Prognostication in Acute Myeloid Leukemia with CBFB-MYH11 Fusion Transcript: Focus on the Role of Molecular Measurable Residual Disease (MRD) Monitoring

Usefulness of KIT mutant transcript levels for monitoring measurable residual disease in t (8;21) acute myeloid leukemia

In addition to RUNX1::RUNX1T1 transcript levels, measurable residual disease monitoring using KIT mutant (KITmut ) DNA level is reportedly predictive of relapse in t (8; 21) acute myeloid leukemia (AML). However, the usefulness of KITmut transcript levels remains unknown. A total of 202 bone marrow samples collected at diagnosis and during treatment from 52 t (8; 21) AML patients with KITmut (D816V/H/Y or N822K) were tested for KITmut transcript levels using digital polymerase chain reaction. The individual optimal cutoff values of KITmut were identified by performing receiver operating characteristics curve analysis for relapse at each of the following time points: at diagnosis, after achieving complete remission (CR), and after Course 1 and 2 consolidations. The cutoff values were used to divide the patients into the KITmut -high (KIT_H) group and the KITmut -low (KIT_L) group. The KIT_H patients showed significantly lower relapse-free survival (RFS) and overall survival (OS) rates than the KIT_L patients after Course 1 consolidation (p = 0.0040 and 0.021, respectively) and Course 2 consolidation (p = 0.018 and 0.011, respectively) but not at diagnosis and CR. The <3-log reduction in the RUNX1::RUNX1T1 transcript levels after Course 2 consolidation was an independent adverse prognostic factor for RFS and OS. After Course 2 consolidation, the KIT_H patients with >3-log reduction in the RUNX1::RUNX1T1 transcript levels (11/45; 24.4%) had similar RFS as that of patients with <3-log reduction in the RUNX1::RUNX1T1 transcript levels. The combination of KITmut and RUNX1::RUNX1T1 transcript levels after Course 2 consolidation may improve risk stratification in t (8; 21) AML patient with KIT mutation.

Symptomatic Patients with Hyperleukocytic FLT3-ITD Mutated Acute Myeloid Leukemia Might Benefit from Leukapheresis

PURPOSE

We aimed to identify subsets of patients who benefit from emergency LA and to establish a therapeutic algorithm for AML patients with hyperleukocytosis.

METHODS

In this single-center retrospective cohort study, a total of 20 consecutive patients underwent LA because of their clinical symptoms. Overall survival (OS) analysis was conducted using the Kaplan-Meier plot method. Univariate and multivariate analyses (using multiple logistic regression) were performed. At the time of diagnosis, all patients received a standard diagnostic workup for AML including FLT3-ITD mutational analysis.

RESULTS

FLT3-ITD mut AML patients receiving LA had a median OS of 437 days (range 5-2379 days) with a corresponding 14-day survival of 92.3%, while FLT3 wt AML patients displayed a significantly lower median OS of only 5 days (range 1-203 days) with a corresponding 14-day survival of 14.3% (p = 0.0001).

CONCLUSIONS

Among patients with clinical symptoms of leukostasis, the subset of FLT3-ITD mut AML patients showed a better outcome with lower early mortality after emergency LA. Based on these observations, we established a therapeutic algorithm for AML patients with hyperleukocytosis.

Minimal Infiltrative Disease Identification in Cryopreserved Ovarian Tissue of Girls with Cancer for Future Use: A Systematic Review

BACKGROUND

Ovarian tissue cryopreservation and transplantation are the only available fertility techniques for prepubertal girls with cancer. Though autotransplantation carries a risk of reintroducing malignant cells, it can be avoided by identifying minimal infiltrative disease (MID) within ovarian tissue.

METHODS

A broad search for peer-reviewed articles in the PubMed database was conducted in accordance with PRISMA guidelines up to March 2023. Search terms included 'minimal residual disease', 'cryopreservation', 'ovarian', 'cancer' and synonyms.

RESULTS

Out of 542 identified records, 17 were included. Ovarian tissues of at least 115 girls were evaluated and categorized as: hematological malignancies (n = 56; 48.7%), solid tumors (n = 42; 36.5%) and tumors of the central nervous system (n = 17; 14.8%). In ovarian tissue of 25 patients (21.7%), MID was detected using RT-qPCR, FISH or multicolor flow cytometry: 16 of them (64%) being ALL (IgH rearrangements with/without TRG, BCL-ABL1, EA2-PBX1, TEL-AML1 fusion transcripts), 3 (12%) Ewing sarcoma (EWS-FLI1 fusion transcript, EWSR1 rearrangements), 3 (12%) CML (BCR-ABL1 fusion transcript, FLT3) and 3 (12%) AML (leukemia-associated immunophenotypes, BCR-ABL1 fusion transcript) patients.

CONCLUSION

While the majority of malignancies were found to have a low risk of containing malignant cells in ovarian tissue, further studies are needed to ensure safe implementation of future fertility restoration in clinical practice.

Prevalence and Clinical Outcome of FMS-Like Tyrosine Kinase Mutations Among Patients With Core Binding Factor-Acute Myeloid Leukemia: Systematic Review and Meta-Analysis

BACKGROUND

Core binding factor acute myeloid leukemia (CBF-AML) belongs to favorable risk group in AML. However, approximately 50% of patients with CBF-AML remain incurable and their outcomes are also determined by the various co-occurring mutations. Though, FMS-like tyrosine kinase-3(FLT3) mutation in AML is associated with poor survival, the prevalence and prognostic significance of FLT3 mutations among CBF-AML is unknown.

PATIENTS AND METHODS

We performed a systematic review and meta-analysis to assess the prevalence of FLT3 mutations (ITD and TKD) among patients with CBF-AML. The pooled prevalence of FLT3 mutations was estimated for patients with CBF-AML, t(8;21) and Inv(16). Pooled odds ratio was calculated to compare the prevalence of various FLT3 mutations within the 2 subsets of CBF-AML. A random effects model was adopted for analysis when heterogenicity existed (P_{heterogenicity}< 0.05 or I² > 50%). Otherwise, a fixed effects model was used.

RESULTS

The pooled prevalence of any FLT3 mutations among patients with CBF-AML was available from 18 studies and was 13% (95% CI: 10%-16%; I² = 79%). Comparison of prevalence of FLT3 mutations between the 2 subgroups of CBF-AML showed that patients with t(8;21) had a higher prevalence of FLT3-ITD [pooled odds ratio(OR): 2.23 (95% CI:1.41-3.53, P < .01)] and lower prevalence of FLT3-TKD [pooled OR: 0.29 (95% CI:0.19-0.44; P < .01)] compared to patients with Inv(16). Additionally, we have discussed the prognostic significance of FLT3 mutations in CBF-AML patients.

CONCLUSION

The prevalence of FLT3-TKD mutation was commoner among Inv(16) AML while FLT3-ITD mutation was commoner among t(8;21) AML. Uniform reporting of outcomes is essential to understand the prognostic significance of FLT3 mutations among CBF-AML.