Flow cytometry-based measurable residual disease (MRD) analysis identifies AML patients who may benefit from allogeneic hematopoietic stem cell transplantation.

Measurable residual disease (MRD) monitoring independently predicts long-term outcomes in patients with acute myeloid leukemia (AML). Of the various modalities available, multiparameter flow cytometry-based MRD analysis is widely used and relevant for patients without molecular targets. In the transplant (HCT) setting, the presence of MRD pre-HCT is associated with adverse outcomes. MRD-negative remission status pre-HCT was also associated with longer overall (OS) and progression-free survival and a lower risk of relapse. We hypothesize that the combination of disease risk and MRD at the time of first complete remission (CR1) could identify patients according to the benefit gained from HCT, especially for intermediate-risk patients. We performed a retrospective analysis comparing the outcomes of HCT versus non-HCT therapies based on MRD status in AML patients who achieved CR1. Time-dependent analysis was applied considering time-to-HCT as a time-dependent covariate and compared HCT versus non-HCT outcomes according to MRD status at CR1. Among 336 patients assessed at CR1, 35.1% were MRD positive (MRDpos) post-induction. MRDpos patients benefitted from HCT with improved OS and relapse-free survival (RFS), while no benefit was observed in MRDneg patients. In adverse-risk patients, HCT improved OS (HR for OS 0.55; p = 0.05). In intermediate-risk patients, HCT benefit was not significant for OS and RFS. Intermediate-risk MRDpos patients were found to have benefit from HCT with improved OS (HR 0.45, p = 0.04), RFS (HR 0.46, p = 0.02), and CIR (HR 0.41, p = 0.02). Our data underscore the benefit of HCT in adverse risk and MRDpos intermediate-risk AML patients.

Comprehensive Genomic Analysis of Noonan Syndrome and Acute Myeloid Leukemia in Adults: A Review and Future Directions.

Acute myeloid leukemia (AML) in the setting of Noonan syndrome (NS) has been reported before without clear guidelines for treatment or prognosis in these subgroups of patients, most likely due to its rarity and incomplete understanding of the pathogenesis of both diseases. In the current era of next-generation sequencing-based genomic analysis, we can better identify patients with NS with more accurate AML-related prognostic markers. Germline mutations in PTPN11 are the most common cause of NS. Somatic mutations in NPM1 occur frequently in AML. Here, we describe a young adult patient with a novel combined germline PTPN11 and somatic NPM1, IDH1,and BCL6 mutations who presented with fatal AML. In addition, a 50.5-Mb interstitial deletion of 7q21.11-q33 in tumor DNA was detected by chromosomal microarray analysis. While mutations in the transcriptional repressor BCL6 are known to contribute to the pathogenesis of diffuse large B cell lymphoma (DLBCL) and chronic lymphocytic leukemia (CLL), its novel identification in this patient suggests an expanded role in aggressive AML. The identification of key molecular aberrations including the overexpression of SHP2, which drives leukemogenesis and tumorigenesis, has led to the development of novel investigational targeted SHP2 inhibitors.

Extramedullary relapses after allogeneic stem cell transplantation for acute myeloid leukemia: clinical characteristics, incidence, risk factors and outcomes.

Acute myeloid leukemia (AML) relapse after allogeneic hematopoietic cell transplant (allo-HCT) is challenging. Data on extramedullary relapse (EMR) after allo-HCT are limited. We analyzed 215 patients with AML who underwent allo-HCT in our institution between January 2005 and December 2015. We limited this retrospective review to patients who received a MA conditioning, were in complete remission (CR) at the time of transplant and who received a matched sibling transplant, all other patients were excluded to avoid heterogeneity. Seventy-seven (35.8%) patients experienced disease relapse, 45 had BMR, and 32 had EMR. The only variable that was statistically associated with EMR post allo-HCT was male sex (OR = 3.2 (1.2, 8.2), p-value = 0.01); there was a trend for association between transplant in >CR2 and EMR (OR = 0.38 (0.14, 1.06), p-value = 0.06). The median overall survival (OS) after relapse for all relapses was 10 months (95% CI 4.839-15.161). The median OS for BMR group was 8 months (95% CI 2.850-13.150) and 14 months for the EMR group (95% CI 5.776-22.224); however, this was not statistically significant, p-value = 0.4. Multivariate analysis revealed that gender, treatment modality, and time from allo-HCT to relapse (≥12 vs. <12 months) have significant association with the post-relapse death. Male gender was the only significant factor associated with EMR.