Extramedullary infiltration at diagnosis and prognosis in children with acute myelogenous leukemia

Extramedullary infiltration in pediatric acute myeloid leukemia: Results from the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) initiative

BACKGROUND

The outcome of extramedullary infiltration (EMI) in pediatric acute myeloid leukemia (AML) is controversial, and little is known about the implications of stem cell transplantation (SCT) and gemtuzumab ozogamicin (GO) treatment on patients with EMI.

METHODS

We retrieved the clinical data of 713 pediatric patients with AML from the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) dataset, and analyzed the clinical and prognostic characteristics of patients with EMI at diagnosis and relapse.

RESULTS

A total of 123 patients were identified to have EMI at diagnosis and 64 presented with EMI at relapse. The presence of EMI was associated with age ≤2 years, M5 morphology, abnormal karyotype, and KMT2A rearrangements. Hyperleukocytosis and complex karyotype were more prevalent in patients with EMI at relapse. Additionally, patients with EMI at diagnosis had a reduced incidence of FLT3 ITD-/NPM1+, whereas those with EMI at relapse displayed a lower frequency of FLT3 ITD+. Patients with EMI at diagnosis exhibited a lower complete remission (CR) rate at the end of Induction Course 1 and higher relapse incidence. Importantly, EMI at diagnosis independently predicted both shorter event-free survival (EFS) and overall survival (OS). Regarding relapse patients, the occurrence of EMI at relapse showed no impact on OS. However, relapse patients with myeloid sarcoma (MS)/no central nervous system (CNS) exhibited poorer OS compared to those with CNS/no MS. Furthermore, regarding patients with EMI at diagnosis, SCT failed to improve the survival, whereas GO treatment potentially enhanced OS.

CONCLUSION

EMI at diagnosis is an independent adverse prognostic risk factor for pediatric AML, and GO treatment potentially improves survival for patients with EMI at diagnosis.

Limited Efficacy of Venetoclax Combination Regimens in Acute Myeloid Leukemia with Extramedullary Relapse

The recently approved BCL2 inhibitor venetoclax (VEN) has achieved promising outcomes in new and relapsed/refractory (R/R) acute myeloid leukemia (AML). Although its use is not well established in R/R AML with extramedullary disease (EMD), some reports have shown promising outcomes. We retrospectively analyzed 11 patients of R/R AML with EMD (with (n = 4) or without (n = 7) concurrent marrow involvement), who were treated with VEN plus decitabine (n = 9) or low-dose cytarabine (n = 2) between May 2020 and October 2020 in Seoul St. Mary's Hospital. The median number of prior treatment lines was 3 (1-6), and most (n = 9, 81.8%) had multiple sites of EMD. Nine patients (81.8%) received concurrent therapy for extramedullary (EM) involvement sites with radiotherapy (RT) (n = 4), surgery (n = 1), and both of them (n = 4). Among 11 patients, 4 patients (36.4%) had either marrow or EM responses to VEN combination; EM response was seen in 1 patient (9.1%, partial response) who had received concurrent RT (25 Gy, 10 fx) during the 1st cycle of VEN combination, and other 3 patients showed marrow response without EM response. After median follow-up of 27.0 months, the median overall survival was estimated to be 5.4 months. To conclude, VEN combination regimens have shown only modest efficacy in EM recurrence of AML with little impact on eliciting EM response.

Acute pancreatitis as initial presentation of acute myeloid leukemia-M2 subtype: A case report

BACKGROUND

Direct infiltration of the pancreas by acute myeloid leukemia (AML) with acute pancreatitis (AP) as an initial symptom is extremely rare. Only once in the literature, the leukemia cells in AML have been implicated as the cause of AP. Pancreatitis caused by a rare predisposing factor is often misdiagnosed as idiopathic pancreatitis or pancreatitis of other common causes. Severe AP (SAP) progresses rapidly with a high fatality rate. Therefore, it is important to identify the predisposing factors in the early stage of SAP, evaluate the condition, determine prognosis, formulate treatment plans, and prevent a recurrence. Here, we describe a case of SAP due to AML.

CASE SUMMARY

A 61-year-old man presented to the hospital with fever and persistent abdominal pain. Blood analysis presented significantly elevated serum amylase and severe thrombocytopenia. Computed tomography examination of the abdomen revealed peripancreatic inflammatory effusion. The patient had no common etiologies and risk factors for AP, but the concurrent severe thrombocytopenia could not be explained by pancreatitis. Finally, the bone marrow aspirate and biopsy inspection revealed the underlying reason for pancreatitis, AML (M2 type based on the French-American-British classifications system).

CONCLUSION

Direct infiltration of the pancrease by acute leukemia, particularly AML cells, is an infrequent cause of AP. Therefore, although AP is a rare extramedullary infiltration characteristic for AML patients, it should be considered when determining the etiology of AP.

Pediatric Myeloid Sarcoma, More than Just a Chloroma: A Review of Clinical Presentations, Significance, and Biology

Myeloid sarcomas (MS), commonly referred to as chloromas, are extramedullary tumors of acute myeloid leukemia (AML) with varying incidence and influence on outcomes. Pediatric MS has both a higher incidence and unique clinical presentation, cytogenetic profile, and set of risk factors compared to adult patients. Optimal treatment remains undefined, yet allogeneic hematopoietic stem cell transplantation (allo-HSCT) and epigenetic reprogramming in children are potential therapies. Importantly, the biology of MS development is poorly understood; however, cell-cell interactions, epigenetic dysregulation, cytokine signaling, and angiogenesis all appear to play key roles. This review describes pediatric-specific MS literature and the current state of knowledge about the biological determinants that drive MS development. While the significance of MS remains controversial, the pediatric experience provides an opportunity to investigate mechanisms of disease development to improve patient outcomes. This brings the hope of better understanding MS as a distinct disease entity deserving directed therapeutic approaches.

C1Q labels a highly aggressive macrophage-like leukemia population indicating extramedullary infiltration and relapse

Extramedullary infiltration (EMI) is a concomitant manifestation that may indicate poor outcome of acute myeloid leukemia (AML). The underlying mechanism remains poorly understood and therapeutic options are limited. Here, we employed single-cell RNA sequencing on bone marrow (BM) and EMI samples from a patient with AML presenting pervasive leukemia cutis. A complement C1Q+ macrophage-like leukemia subset, which was enriched within cutis and existed in BM before EMI manifestations, was identified and further verified in multiple patients with AML. Genomic and transcriptional profiling disclosed mutation and gene expression signatures of patients with EMI that expressed high levels of C1Q. RNA sequencing and quantitative proteomic analysis revealed expression dynamics of C1Q from primary to relapse. Univariate and multivariate analysis demonstrated adverse prognosis significance of C1Q expression. Mechanistically, C1Q expression, which was modulated by transcription factor MAF BZIP transcription factor B, endowed leukemia cells with tissue infiltration ability, which could establish prominent cutaneous or gastrointestinal EMI nodules in patient-derived xenograft and cell line-derived xenograft models. Fibroblasts attracted migration of the C1Q+ leukemia cells through C1Q-globular C1Q receptor recognition and subsequent stimulation of transforming growth factor β1. This cell-to-cell communication also contributed to survival of C1Q+ leukemia cells under chemotherapy stress. Thus, C1Q served as a marker for AML with adverse prognosis, orchestrating cancer infiltration pathways through communicating with fibroblasts and represents a compelling therapeutic target for EMI.

Cerebrospinal fluid interleukin-6 is a potential diagnostic biomarker for central nervous system involvement in adult acute myeloid leukemia

Objective

We evaluated the correlation between cerebrospinal fluid (CSF) cytokine levels and central nervous system (CNS) involvement in adult acute myeloid leukemia (AML).

Methods

The study sample consisted of 90 patients diagnosed with AML and 20 with unrelated CNS involvement. The AML group was divided into two sub-groups: those with (CNS+, n=30) and without CNS involvement (CNS-, n=60). We used a cytometric bead assay to measure CSF interleukin (IL)-2, IL-4, IL-6, and IL-10, tumor necrosis factor-α, interferon-γ, and IL-17A. We used receiver operating characteristic curves to evaluate the ability of CSF cytokine levels to identify CNS involvement in adult AML.

Results

CSF IL-6 levels were significantly higher in CNS+adult AML patients and positively correlated with the lactate dehydrogenase levels (r=0.738, p<0.001) and white blood cell (WBC) count (r=0.455, p=0.012) in the blood, and the protein (r=0.686, p<0.001) as well as WBC count in the CSF (r=0.427, p=0.019). Using a CSF IL-6 cut-off value of 8.27 pg/ml yielded a diagnostic sensitivity and specificity was 80.00% and 88.46%, respectively (AUC, 0.8923; 95% CI, 0.8168–0.9678). After treating a subset of tested patients, their CSF IL-6 levels decreased. Consequently, the elevated CSF IL-6 levels remaining in CNS+ adult AML patients post-treatment were associated with disease progression.

Conclusion

CSF IL-6 is a promising marker for the diagnosis of adult AML with CNS involvement and a crucial dynamic indicator for therapeutic response.

Successful Treatment of Pediatric Acute Myeloid Leukemia Presenting with Hyperbilirubinemia Secondary to Myeloid Sarcoma: A Case Report

Myeloid sarcoma (MS), a tumor consisting of myeloid blasts with or without maturation, occurs at anatomical sites other than the bone marrow. MS of the gastrointestinal tract presenting with jaundice in children is rare. We report the case of a 4-year-old boy with a 6-week history of symptoms of obstructive jaundice due to a peripancreatic mass compressing the common bile duct. Six weeks later, blasts were found in a peripheral smear prior to surgical biopsy; bone marrow evaluation and flow cytometry results led to a diagnosis of acute myeloid leukemia (AML) with MS. No further invasive testing or temporary drainage was performed. He was started on induction therapy with full therapeutic doses of cytarabine, dose reductions of etoposide, and escalating doses of daunorubicin. His liver enzymes normalized, and he completed subsequent cycles of chemotherapy with full doses. The abdominal ultrasound showed resolution of the mass after the second cycle of chemotherapy. He is currently in remission three years after completing therapy. AML-directed chemotherapy in patients with obstructive jaundice secondary to MS may be beneficial without requiring invasive testing or temporary drainage procedures. Daily follow-up is crucial for chemotherapy dose modifications. Management plans should be individualized according to the patient’s clinical condition.

Clinical Characteristics and Treatment Outcomes of Myeloid Sarcoma in Children: The Experience of the Polish Pediatric Leukemia and Lymphoma Study Group

Introduction

Myeloid sarcoma (MS) is an extramedullary malignant tumor composed of immature myeloid cells. It occurs in patients with acute myeloid leukemia (AML), myelodysplastic syndrome (MDS), or chronic myeloid leukemia (CML). MS may coincide with disease diagnosis or precede bone marrow involvement by months or even years; it can also represent the extramedullary manifestation of a relapse (1, 2).

Aim

The aim of this study is to describe clinical characteristics of children diagnosed with MS in Poland as well as to analyze diagnostic methods, treatment, and outcomes including overall survival (OS), relapse-free survival (RFS), and event-free survival (EFS). The study also attempted to identify factors determining treatment outcomes.

Patients

The study group comprised 43 patients (F=18, M=25) aged 0-18 years (median age, 10.0 years; mean age, 8.8 years) diagnosed with MS based on tumor biopsy and immunohistochemistry or identification of underlying bone marrow disease and extramedullary tumor according to imaging findings.

Methods

The clinical data and diagnostic and therapeutic methods used in the study group were analyzed. A statistical analysis of the treatment outcomes was conducted with STATISTICA v. 13 (StatSoft, Inc., Tulsa, OK, USA) and analysis of survival curves was conducted with MedCalc 11.5.1 (MedCalc Software, Ostend, Belgium). Statistical significance was considered at p<0.05.

Results

In the study group, MS was most frequently accompanied by AML. The most common site of involvement was skin, followed by orbital region. Skin manifestation of MS was more common in the age group <10 years. The most frequent genetic abnormality was the t(8;21)(q22;q22) translocation. The 5-year OS probability (pOS), 5-year RFS probability (pRFS), and 5-year EFS probability (pEFS) were 0.67 ± 0.08, 0.79 ± 0.07, and 0.65 ± 0.08, respectively. In patients with isolated MS and those with concurrent bone marrow involvement by AML/MDS, pOS values were 0.56 ± 0.12 and 0.84 ± 0.09 (p=0.0251), respectively, and pEFS values were 0.56 ± 0.12 and 0.82 ± 0.08 (p=0.0247), respectively. In patients with and without the t(8;21)(q22;q22) translocation, pEFS values were 0.90 ± 0.09 and 0.51 ± 0.14 (p=0.0490), respectively.

Conclusions

MS is a disease with a highly variable clinical course. Worse treatment outcomes were observed in patients with isolated MS compared to those with concurrent bone marrow involvement by AML/MDS. Patients with the t(8;21)(q22;q22) translocation were found to have significantly higher pEFS. MS location, age group, chemotherapy regimen, surgery, and/or radiotherapy did not have a significant influence on treatment outcomes. Further exploration of prognostic factors in children with MS is indicated.

Extramedullary Infiltration in Pediatric Acute Myeloid Leukemia on Surveillance Magnetic Resonance Imaging and its Relationship With Established Risk Factors

PURPOSE

Extramedullary infiltration (EMI) is a rare condition defined by the accumulation of myeloid tumor cells beyond the bone marrow. The clinical significance is still controversial. This study was aimed to evaluate the incidence, characteristics, and prognostic significance of EMI on complete magnetic resonance imaging (MRI) investigation in newly diagnosed pediatric acute myeloid leukemia (AML) patients who are asymptomatic without clinical evidence to suspect EMI.

MATERIALS AND METHODS

Retrospective clinical and radiologic review of 121 patients with MRI examination at the time of initial diagnosis of AML without any clinical evidence suggestive of EMI was performed. Patients were divided into 2 groups according to the presence or absence of EMI, and the relationship between EMI and established risk factors was analyzed. Initial white blood cell count, the occurrence of an event (including relapse, death, and primary refractory disease), survival status, and detailed information on cytogenetic/molecular status was performed by a thorough review of electronic medical records system. All patients underwent full imaging evaluation with the contrast-enhanced whole body and some regional MRI at the time of initial diagnosis.

RESULTS

The median age at diagnosis was 10.77 years (range, 0.37 to 18.83 y). Based on the risk stratification system of AML, 36, 45, and 40 patients are classified as low-risk, intermediate-risk, and high-risk groups, respectively. MRI at the time of the initial diagnosis of AML revealed 35 of 121 patients (28.9%) with EMI. The most common site of EMI was a skull, followed by the lower extremity bone and meninges of the brain. The median age at diagnosis was significantly younger in patients with EMI (7.87 vs. 11.08 y, P=0.0212). Low incidence of FLT3/ITD mutation, low incidence of AML-ETO gene rearrangement, and the larger extent and more severe degree of bone marrow involvement was related with EMI. However, there was no significant prognostic difference in event-free survival and overall survival regardless of the presence of EMI in the overall patient population and each risk group. The location of EMI occurrence was also not related to prognosis.

CONCLUSIONS

Even if EMI symptoms are not evident, surveillance MRI scans at the initial diagnosis of pediatric AML patients are very helpful in detecting a significant number of EMIs. Younger age, some molecular features, and more severe bone marrow involvement of AML patients were related with EMI. However, there was no significant prognostic difference between patients with or without EMI regardless of risk group. Further prospective investigation is necessary to validate the prognostic effect of EMI in a larger group of patients with different risk groups.

Clinical characteristics, pathology features and outcomes of pediatric myeloid sarcoma: A retrospective case series

PURPOSE

Myeloid sarcoma (MS) is a rare extramedullary mass with myeloid expression, which is easy to be missed and misdiagnosed, especially in the pediatric population. We analyze the clinicopathological characteristics, immunophenotypic, cytogenetic, and molecular studies, therapeutic approaches, and outcomes, to optimize the management of such patients.

METHODS

A retrospective, single-center, case series study of eleven children diagnosed with MS by pathology was performed.

RESULTS

The male-to-female ratio was 8:3, and the median age at diagnosis was 7 years. The most commonly involved sites were the skin and orbital region, followed by lymph nodes, central nervous system, and testis. Seven cases (64%) with Class I-MS and four cases (36%) presented as Class II-MS. Immunohistochemically, MPO and CD117 were the most commonly expressed markers, followed by CD33, CD43, CD34, CD68, and lysozyme. Chromosomal abnormalities were detected in 4 patients. Two patients had the presence of deleterious mutations (FLT3, ASXL, KIT, and DHX15) on molecular detection. Ten patients were treated with chemotherapy based on AML regimens. The median follow-up time was 33.5 months in eleven patients. Two patients relapsed, one died, and one lost to follow-up. The 2-year overall survival (OS) rate estimated by Kaplan-Meier curves was 90.9% ± 8.7%, and the event-free survival (EFS) rate was 64.9% ± 16.7%.

CONCLUSIONS

MS diagnosis is usually challenging. Adequate tumor biopsy and expanded immunohistochemistry are necessary for the correct diagnosis of MS. Early and regular systemic chemotherapy promises long-term survival.

CNS involvement in AML at diagnosis is rare and does not affect response or survival: data from 11 ECOG-ACRIN trials

There was no significant difference in CR rate and OS among patients with CNS involvement, other EMD, or no EMD.

The incidence of CNS involvement of newly diagnosed AML is low, irrespective of whether an LP is mandatory or not.

Central nervous system (CNS) involvement in patients with newly diagnosed acute myeloid leukemia (AML) is rare, and systematic data regarding outcome are scarce. This retrospective study summarized data from 11 consecutive Eastern Cooperative Oncology Group-American College of Radiology Imaging Network (ECOG-ACRIN) clinical trials for patients with newly diagnosed AML. In all, 3240 patients with AML were analyzed, and 36 (1.11%) were found to have CNS involvement at diagnosis. The incidence of CNS disease among the 5 studies with per protocol mandatory lumbar puncture (LP) was similar to the incidence among studies in which LP was performed at the discretion of the investigator (0.86% vs 1.41%; P = .18). There was no significant difference in the rate of complete remission (CR) among patients with CNS involvement and those with other extramedullary disease (EMD) sites or those with no EMD (52.8% vs 59.3%-60%). The median overall survival (OS) for patients who were CNS positive, who had other EMD, or who had no EMD was 11.4, 11.3, and 12.7 months, respectively. There was no difference in OS among patients with CNS involvement, those with other EMD (hazard ratio [HR], 0.96; adjusted P = .84), and those with no EMD (HR, 1.19; adjusted P = .44). In conclusion, the reported incidence of CNS involvement in patients with newly diagnosed AML is low (1.1%), irrespective of whether an LP is mandatory or not. The presence of CNS disease at diagnosis in and of itself does not seem to portend a poor prognosis for achieving an initial CR or for OS.

Gastrointestinal Myeloid Sarcoma a Case Presentation and Review of the Literature

Myeloid sarcomas can be detected in up to 30% of acute myeloid leukemia cases or occur de-novo without bone marrow involvement. The most frequent localization of myeloid sarcomas in the abdominal cavity is the small intestine, and gastric presentations are infrequent, frequently misdiagnosed, and a high level of suspicion should exist when the characteristic histomorphology features are present. The current review features a case report with gastric presentation of myeloid sarcoma in a patient with a diagnosis of acute myeloid leukemia with trisomy 8. In addition, a review of the literature of intestinal-type myeloid sarcomas shows that less than 15% of these cases have been reported in the stomach. The most common molecular aberrancy detected in intestinal myeloid sarcomas is the fusion protein CBFB-MYH11. A review of several large studies demonstrates that the presence of myeloid sarcoma does not constitute an independent prognostic factor. The therapeutic approach will be tailored to the specific genetic abnormalities present, and systemic chemotherapy with hematopoietic stem cell transplant is the most efficient strategy.

A rare PALB2 germline variant causing G2/M cell cycle arrest is associated with isolated myelosarcoma in infancy

BACKGROUND

Isolated myelosarcoma of infancy is a rare presentation of acute myelogenous leukaemia (AML). Because of its rarity and early onset in infancy underlying genetic predisposition is potentially relevant in disease initiation.

METHODS AND RESULTS

We report an oncologic emergency in an infant with thoracic and intraspinal aleukaemic myeloid sarcoma causing acute myelon compression and lower leg palsy. Whole-exome sequencing of the patient's germline DNA identified a rare PALB2 (OMIM 610355) variant (p.A1079S), which is located in a domain critical for the gene's proper function within the homology-directed repair pathway. In line with potential DNA damage repair defects mediated by the PALB2 deregulation, the patient's fibroblasts showed increased sensitivity towards radiation and DNA intercalating agents.

CONCLUSION

Therefore, we suggest PALB2 p.A1079S as a pathogenic variant potentially contributing to the here observed patient phenotype.

Mesothelin is a novel cell surface disease marker and potential therapeutic target in acute myeloid leukemia

In an effort to identify acute myeloid leukemia (AML)-restricted targets for therapeutic development in AML, we analyzed the transcriptomes of 2051 children and young adults with AML and compared the expression profile with normal marrow specimens. This analysis identified a large cohort of AML-restricted genes with high expression in AML, but low to no expression in normal hematopoiesis. Mesothelin (MSLN), a known therapeutic target in solid tumors, was shown to be highly overexpressed in 36% of the AML cohort (range, 5-1077.6 transcripts per million [TPM]) and virtually absent in normal marrow (range, 0.1-10.7 TPM). We verified MSLN transcript expression by quantitative reverse transcription polymerase chain reaction, confirmed cell surface protein expression on leukemic blasts by multidimensional flow cytometry, and demonstrated that MSLN expression was associated with promoter hypomethylation. MSLN was highly expressed in patients with KMT2A rearrangements (P < .001), core-binding factor fusions [inv(16)/t(16;16), P < .001; t(8;21), P < .001], and extramedullary disease (P = .001). We also demonstrated the presence of soluble MSLN in diagnostic serum specimens using an MSLN-directed enzyme-linked immunosorbent assay. In vitro and in vivo preclinical efficacy of the MSLN-directed antibody-drug conjugates (ADCs) anetumab ravtansine and anti-MSLN-DGN462 were evaluated in MSLN+ leukemia cell lines in vitro and in vivo, as well as in patient-derived xenografts. Treatment with ADCs resulted in potent target-dependent cytotoxicity in MSLN+ AML. In this study, we demonstrate that MSLN is expressed in a significant proportion of patients with AML and holds significant promise as a diagnostic and therapeutic target in AML, and that MSLN-directed therapeutic strategies, including ADCs, warrant further clinical investigation.

Myeloid sarcoma of the heart: Extramedullary relapse of acute myeloblastic leukemia, presenting with complete heart block and atrial flutter after second allogeneic stem cell transplantation

We report isolated extramedullary relapse in a 14-year-old boy, sequentially presenting with intestinal and cardiac myeloid sarcoma (MS). Acute myeloblastic leukemia M5 was diagnosed 41 months ago. On the 14th month of the second HSCT, he presented with ileus and underwent surgical treatment. After 2 weeks, arrhythmia, bradycardia, complete heart block, and atrial flutter developed and echocardiography revealed multiple cardiac masses. There was no bone marrow relapse but pathology of the intestinal biopsy showed leukemic infiltration. Patient was successfully treated with a permanent pacemaker and salvage chemotherapy. To the best of our knowledge, this is the first pediatric cardiac MS developed after HSCT.

miR-29c&b2 encourage extramedullary infiltration resulting in the poor prognosis of acute myeloid leukemia

Extramedullary infiltration (EMI), as a concomitant symptom of acute myeloid leukemia (AML), is associated with low complete remission and poor prognosis in AML. However, the mechanism of EMI remains indistinct. Clinical trials showed that increased miR-29s were associated with a poor overall survival in AML [14]. Nevertheless, they were proved to work as tumor suppressor genes by encouraging apoptosis and inhibiting proliferation in vitro. These contradictory results led us to the hypothesis that miR-29s may play a notable role in the prognosis of AML rather than leukemogenesis. Thus, we explored the specimens of AML patients and addressed this issue into miR-29c&b2 knockout mice. As a result, a poor overall survival and invasive blast cells were observed in high miR-29c&b2-expression patients, and the wildtype mice presented a shorter survival with heavier leukemia infiltration in extramedullary organs. Subsequently, we found that the miR-29c&b2 inside leukemia cells promoted EMI, but not the one in the microenvironment. The analysis of signal pathway revealed that miR-29c&b2 could target HMG-box transcription factor 1 (Hbp1) directly, then reduced Hbp1 bound to the promoter of non-muscle myosin IIB (Myh10) as a transcript inhibitor. Thus, increased Myh10 encouraged the migration of leukemia cells. Accordingly, AML patients with EMI were confirmed to have high miR-29c&b2 and MYH10 with low HBP1. Therefore, we identify that miR-29c&b2 contribute to the poor prognosis of AML patients by promoting EMI, and related genes analyses are prospectively feasible in assessment of AML outcome.

Effect of extramedullary disease on allogeneic hematopoietic cell transplantation for pediatric acute myeloid leukemia: a nationwide retrospective study

Children with acute myeloid leukemia (AML) commonly develop extramedullary disease (EMD), which comprises central nervous system (CNS) lesions and myeloid sarcoma (MS). In this retrospective analysis, we aimed to determine the effect of EMD on the outcomes of allogeneic hematopoietic cell transplantation (HCT) in 678 pediatric patients with de novo AML (median age, 7 years; range, 0.3-15 years) between 2006 and 2016. We compared the outcomes between patients with (EMD group, n = 158; CNS lesion, n = 47, CNS lesion + MS, n = 9, and MS, n = 102) and without EMD at diagnosis (non-EMD group, n = 520). Survivors were followed for a median of 4.5 years, and the 4-year overall survival (OS) rates were 60.6% and 56.4% in the EMD and non-EMD groups, respectively (P = 0.60). No significant differences in OS were observed with respect to the EMD site, except bone lesions, which were associated with poor OS after HCT in a non-remission status. A multivariate analysis revealed that EMD did not affect the outcomes of HCT. In conclusion, the study findings suggest that EMD should not be considered a poor prognostic factor in HCT for children with AML.

Characteristics and prognosis of pediatric myeloid sarcoma in the cytogenetic context of t(8;21)

The prognosis of myeloid sarcoma (MS) is controversial. Many reports indicated that orbital-MS has a good prognosis and is closely related to t(8;21), but the prognostic role of MS in pediatric t(8;21) AML is unclear. We retrospectively analyzed data from 127 patients with pediatric t(8;21) AML diagnosed between January 2010 and June 2018. We compared patients with (n = 30) and without MS (n = 97). The median follow-up time was 52.6 months. The proportion of t(8;21) AML patients with MS was 23.6%. Males were more likely to have MS than females. The complete remission rate after the first course of induction chemotherapy and the 3-year relapse-free survival (RFS) among patients with MS were lower than those among patients without MS (60% vs. 78.4%, p = 0.045) (68.8 ± 8.8% vs. 88.0 ± 3.4%, p = 0.004). The female sex and a higher level of RUNX1/RUNX1T1 transcripts after consolidation were risk factors for poor RFS among patients with MS. Our data showed that MS was an independent risk factor in pediatric t(8;21) AML. Close monitoring of measurable residual disease of the bone marrow and extramedullary lesions is needed to guide stratified treatment.

The diagnostic and prognostic value of MRI in central nervous system involvement of acute myeloid leukemia: a retrospective cohort of 84 patients

ABSTRACT Objective: To assess the diagnostic and prognostic value of magnetic resonance imaging (MRI) in Acute Myeloid Leukemia (AML) complicated with central nervous system leukemia (CNSL). Methods: A total of 84 patients with AML and confirmed of CNSL from January 2010 to September 2019 were selected and underwent MRI scan. We retrospectively analyzed their MRI findings, summarized the imaging features of AML central infiltration, and assessed the guiding significance of MRI on diagnosis and prognosis of this disease. Results: A total of 52 patients (61.90%, 52/84) had abnormal MRI findings, of which 31 cases clearly indicated intracranial infiltration of leukemia. Among the 31 patients, the most common site of infiltration is parenchyma (19/31). Most MRI of these patients showed multiple lesions with low T1 signal and high T2 signal, which were more obvious on enhanced scan. Sensitivity of MRI in diagnosing AML central infiltration was 36.90%. Despite of its low sensitivity, it still had superior diagnostic value on some patients with false-negative CSF. The median disease-free survival (DFS) and overall survival (OS) time of patients with MRI clearly indicated central invasion were 4 and 9 months, respectively. But there was no significant difference in survival analysis compared with MRI negative patients (including abnormal but non-invasive). Conclusion: MRI manifestation of central infiltration in AML patients has certain characteristic findings, which is helpful to improve the diagnostic efficiency. Prognosis of MRI positive patients is relatively worse than that of MRI negative patients however there is no siginificant difference.

The value of 18F-FDG PET/CT in the prediction of clinical outcomes of patients with acute leukemia treated with allogeneic hematopoietic stem cell transplantation

The present study aimed to determine whether ¹⁸F-FDG PET/CT performed before and/or after allogeneic hematopoietic stem cell transplantation (allo-HSCT) can predict clinical outcomes in acute leukemia (AL). A total of 79 examinations comprising 72 patients with AL who underwent ¹⁸F-FDG PET/CT before and/or after allo-HSCT were retrospectively enrolled between January 2011 and January 2019. Outcomes were assessed using overall survival (OS) and disease-free survival (DFS). A total of 63 examinations were PET-positive, while 16 examinations were PET-negative. Increased BM and splenic ¹⁸F-FDG uptake were observed in 24 (19/79) and 14% (11/79) of examinations, respectively. ¹⁸F-FDG-avid lymph nodes were observed in 38% (30/79) of examinations. E_NE_ME_S involvement was detected in 44% (35/79) of examinations. The presence of E_NE_ME_S involvement [OS hazard ratio (HR), 6.399; 95% confidence interval (CI), 1.843–22.224; P=0.003; post-HSCT OS: HR, 7.203; 95% CI, 1.510–34.369; P=0.013; DFS HR, 3.671; 95% CI, 1.145–11.768; P=0.029], post-transplantation minimal residual disease (DFS HR, 4.381; 95% CI, 1.594–12.040; P=0.004; pre-HSCT OS HR, 11.455; 95% CI, 1.336–98.179; P=0.026) and disease status (OS HR, 0.330; 95% CI, 0.128–0.848; P=0.021; post-HSCT OS HR, 0.195; 95% CI, 0.050–0.762; P=0.019; DFS: HR, 0.278; 95% CI, 0.091–0.851; P=0.025) could serve as an adverse prognostic factor in patients with AL treated with allo-HSCT. ¹⁸F-FDG PET/CT before and/or after allo-HSCT was a predictor for OS and DFS in patients with AL. E_NE_ME_S involvement detected using ¹⁸F-FDG PET/CT may help identify patients with AL who are likely to have unfavorable clinical outcomes.

Prognostic Impact of Extramedullary Infiltration in Pediatric Low-risk Acute Myeloid Leukemia: A Retrospective Single-center Study Over 10 Years

BACKGROUND

The impact of extramedullary infiltration (EMI) on the clinical outcomes of pediatric patients with acute myeloid leukemia (AML) are controversial.

PATIENTS AND METHODS

A total of 214 pediatric patients with low-risk AML were classified as having EMI (central nervous leukemia [CNSL] and/or myeloid sarcoma [MS]) and not having EMI. Patients with isolated MS before AML diagnosis by bone marrow examination were confirmed with histopathologic examination. For patients diagnosed with AML by bone marrow examination, a thorough physical examination and radiologic imaging were used to confirm MS.

RESULTS

Male gender, a high white blood cell count, the FAB-M5 subtype, t(8;21) and t(1;11) abnormalities, and c-KIT mutations were associated with EMI. The presence of MS was associated with a low complete remission rate (63.6% vs. 79.4%; P = .000) and poor 3-year relapse-free survival (RFS) (62.6% ± 7.5% vs. 87.0% ± 2.8%; P = .000) and 3-year overall survival (73.5% ± 7% vs. 88.8% ± 2.6%; P = .011). Multivariate analysis revealed that MS was a poor prognostic factor for RFS and overall survival. Bone infiltration was an independent risk factor for inferior RFS with MS. Patients with CNSL had a low complete remission rate (58.3% vs. 77.2%; P = .045); however, CNSL did not significantly affect the survival of low-risk patients with AML.

CONCLUSION

MS should be considered an independent risk factor to guide stratified treatment.

MiR-144: A New Possible Therapeutic Target and Diagnostic/Prognostic Tool in Cancers

MicroRNAs (miRNAs) are small and non-coding RNAs that display aberrant expression in the tissue and plasma of cancer patients when tested in comparison to healthy individuals. In past decades, research data proposed that miRNAs could be diagnostic and prognostic biomarkers in cancer patients. It has been confirmed that miRNAs can act either as oncogenes by silencing tumor inhibitors or as tumor suppressors by targeting oncoproteins. MiR-144s are located in the chromosomal region 17q11.2, which is subject to significant damage in many types of cancers. In this review, we assess the involvement of miR-144s in several cancer types by illustrating the possible target genes that are related to each cancer, and we also briefly describe the clinical applications of miR-144s as a diagnostic and prognostic tool in cancers.

Prognostic Role of Postinduction Minimal Residual Disease and Myeloid Sarcoma Type Extramedullary Involvement in Pediatric RUNX1-RUNX1T1 (+) Acute Myeloid Leukemia

BACKGROUND

Acute myeloid leukemia with the t(8;21)(q22;q22) rearrangement (RUNX1-RUNX1T1 (+) AML) is known to have a favorable prognosis. Our study aimed to determine the most important prognostic variables among an aggregate of clinical, genetic, and treatment response-based factors in pediatric RUNX1-RUNX1T1 (+) AML.

MATERIALS AND METHODS

We analyzed the characteristics and outcome of 40 patients who were diagnosed with and treated for RUNX1-RUNX1T1 (+) AML from April 2008 to December 2016 at our institution.

RESULTS

A<-2.2 log fusion transcript decrement after remission induction, myeloid sarcoma type extramedullary involvement (EMI) at diagnosis, higher initial white blood cell count, and presence of KIT mutation predicted lower event-free survival. Both lower fusion transcript decrement after remission induction and the presence of EMI at diagnosis proved to be significant adverse factors in the multivariate study. The 5-year event-free survival was 70.0±7.2% (28/40); 8 of the 12 relapsed patients survive disease-free, resulting in 5-year overall survival of 89.5±5.0% (36/40).

CONCLUSIONS

Kinetics of response to remission induction chemotherapy, measured in terms of the PCR value for the fusion transcript, and the presence of myeloid sarcoma type EMI at diagnosis may predict the risk of relapse in pediatric RUNX1-RUNX1T1 (+) AML.

Significance of CXCL12/CXCR4 Ligand/Receptor Axis in Various Aspects of Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is defined as an aggressive disorder which is described by accumulation of immature malignant cells into the bone marrow. Chemokine-receptor axes are defined as factors involved in AML pathogenesis and prognosis. The chemokine receptor CXCR4 along with its ligand, CXCL12 fit in important players that are actively involved in the cross-talk between leukemia cells and bone marrow microenvironment. Therefore, according to the above introductory comments, in this review article, we have focused on delineating some parts played by CXCL12/CXCR4 axis in various aspects of AML malignancy. Targeting both leukemic and stromal cell interaction is nowadays accepted as a wide and attractive strategy for improving the outcome of treatment in AML in a non-cell autonomous manner. This strategy might be employed in a wide variety of AML patients regardless of their causative mutations. In addition to several potential targets involved in the disruption of malignant leukemic cells from their specific protective niches, compounds which interfere with CXCL12/CXCR4 axis have also been explored in multiple early-phase established clinical trials. Moreover, extensive research programs are exploring novel leading mechanisms for leukemia-stromal interactions that appear to find out novel therapeutic targets within the near future.

Pediatric myeloid sarcoma: a single institution clinicopathologic and molecular analysis

Myeloid sarcoma (MS) is a neoplastic condition composed of immature myeloid cells involving an extramedullary site. We investigated underlying chromosomal and molecular alterations to assess potential molecular markers of prognosis and outcome in this rare pediatric disease. We conducted a retrospective review of clinicopathologic and cytogenetic data from 33 pediatric patients with MS (ages 1 month-18 years) at our institution over a 32 year period (1984-2016). Tissue-based cancer microarray and targeted next-generation sequencing analysis were performed on six cases. The median age at diagnosis was 2.8 years with a male-to-female ratio of 2.6:1. MS is commonly presented with concomitant marrow involvement (n = 12, 36.4%) or as a recurrence of acute myeloid leukemia (AML; n = 14, 42.4%). The skin (n = 18, 54.5%) and soft tissue (n = 9, 27.3%) were the most common sites of involvement. Twenty-one of 25 samples (84.0%) harbored chromosomal aberrations; KMT2A alterations (n = 10, 40.0%) or complex cytogenetics (n = 7, 28.0%) were most frequent. Mutations in RAS, tyrosine kinase, cell signaling, and chromatin remodeling genes were detected. When compared to pediatric patients with AML without extramedullary involvement (EMI), inferior overall survival (OS) was observed (18.8 months vs. 89.3 months, p = .008). Pediatric patients with MS with non-favorable cytogenetics [abnormalities other than t(8;21), inv(16)/t(16;16), or t(15;17)] had a significantly lower OS compared to patients with AML with non-favorable cytogenetics and no extramedullary involvement (8.0 months vs. 28.1 months, p < .001). Pediatric MS is a rare disease with diverse clinical presentations. Non-favorable cytogenetics may be a poor prognostic marker for pediatric patients with MS and molecular diagnostics can assist with risk stratification and identify potentially actionable targets.

Myeloid sarcoma is associated with poor clinical outcome in pediatric patients with acute myeloid leukemia

PURPOSE

The impact of myeloid sarcoma (MS) on clinical outcome of pediatric acute myeloid leukemia (AML) patients remains controversial. Moreover, little is known about the role of stem cell transplantation (SCT) in such patients.

METHODS

Clinical data of patients with AML under 18 years of age were retrieved from the TARGET dataset. We analyzed the prevalence, clinical profile, molecular characteristics, and prognosis of MS in these patients.

RESULTS

Among 884 pediatric patients with AML, the frequency of MS was 12.3%. Pediatric AML with MS was associated with age under 1-year, abnormal cytogenetics, and KMT2A rearrangement. Moreover, MS was associated with a low complete remission rate, high induction death, poor 5-year EFS, and OS. KMT2A rearrangement had a negative impact on clinical outcome in AML patients with MS. In addition, SCT had no significant effect on the survival of AML patients with MS. Multivariate analysis revealed that MS was an unfavorable prognostic factor in pediatric AML in terms of EFS (Hazard ratio 1.670, P < 0.001) and OS (Hazard ratio 1.623, P = 0.004).

CONCLUSIONS

The presence of MS at diagnosis of pediatric AML is associated with poor clinical outcomes, particularly when associated with KMT2A rearrangements. Moreover, pediatric patients with AML and MS may not benefit from SCT.

Consensus in Identification and Stability of Symptom Clusters Using Different Symptom Dimensions in Newly Diagnosed Acute Myeloid Leukemia Patients Undergoing Induction Therapy

CONTEXT

An unresolved issue in symptom cluster (SC) research is that the numbers and types of SCs vary based on the multiple dimensions of the experienced symptoms that are used for SC identification.

OBJECTIVE

This study aimed to identify SCs using the ratings of occurrence, severity, and distress in newly diagnosed acute myeloid leukemia (AML) patients at three stages of their induction therapy (i.e., T1, T2, and T3). Then, we evaluated the consensus among the numbers and types of symptoms in each SC identified by multiple dimensions over time.

METHOD

The Chinese version of the Memorial Symptom Assessment Scale was used to evaluate the occurrence, severity, and distress ratings of 32 symptoms in patients newly diagnosed with AML during their induction therapy. Exploratory factor analysis was used for SCs identification.

RESULTS

Using the three dimensions in the AML patients (n = 126), four SCs were identified at T1 and T3 and three SCs were identified at T2. The number of symptoms in individual SCs varied over time, whereas the specific symptoms in SCs remained similar over time. The severity ratings fit the data better than did the ratings of occurrence and distress.

CONCLUSION

These findings provided insights into the most common SCs in AML patients undergoing induction therapy by multidimensional evaluation and could lay the foundation for future targeted symptom interventions. Further studies are needed to explore the mechanisms of SCs in AML patients undergoing the chemotherapy.

Expression of programmed death ligand 1 is associated with poor prognosis in myeloid sarcoma patients

Myeloid sarcoma (MS) is a rare condition and is an extramedullary tumour of immature myeloid cells. It is now known that the programmed death 1 (PD-1)/programmed death ligand 1 (PD-L1) pathway suppresses the host antitumor responses and that these products are expressed on both tumour cells and tumour-infiltrating cells in various malignancies. However, little is known about the significance of PD-1/PD-L1 expression on tumour cells and tumour microenvironmental cells in MS. To investigate the clinicopathological significance of PD-1/PD-L1 expression in MS, we analyzed 98 patients by immunohistochemistry. Of these, 10.2% of cases had neoplastic tumour cells positive for PD-L1 (nPD-L1⁺ ). However, the rate of nPD-L1⁺ was <5% (range: 0.27 to 2.97%). On the other hand, PD-L1 expression on 1 or more of stromal cells in the tumour microenvironment (miPD-L1⁺ ) was observed in 37.8% of cases. Because all nPD-L1⁺ cases expressed PD-1 on less than 5% of tumour cells, we compared the miPD-L1⁺ and miPD-L1^- groups. There was a correlation between miPD-L1⁺ status and the number of PD-1-expressing tumour -infiltrating lymphocytes (PD-1⁺ TILs; P = .0229). miPD-L1⁺ was found to be associated with poorer overall survival and progression-free survival (P = .00392, P = .00261, respectively). Multivariate analysis also confirmed miPD-L1⁺ to be an independent poor prognostic factor. In conclusion, our study indicated that the immunotherapy blocking the PD-1/PD-L1 pathway may improve the clinical outcome of MS.

Involvement of central nervous system in adult patients with acute myeloid leukemia: Incidence and impact on outcome

Incidence and effect on outcome of central nervous system (CNS) involvement in adult patients with acute myeloid leukemia (AML) is not clearly defined. To address this issue, 103 consecutive adult patients with newly diagnosed AML, regardless of neurologic symptoms, were submitted to a routine explorative lumbar puncture. Cerebrospinal fluid (CSF) samples were collected from 65 males and 38 females. All 103 CSF samples were examined by conventional cytology (CC) whereas 95 (92%) also by flow cytometry (FCM). At diagnosis, 70 patients (68%) were CNS negative (CNS-), whereas 33 (32%) were CNS positive (CNS+). In 11 of 33 (33%), CNS infiltration was documented either by CC or FCM , in 21 (67%) only by FCM. CNS positivity was significantly associated with a M4-M5 phenotype of the underlying AML (P = .0003) and with high levels of lactate dehydrogenase (P = .006). Overall, 80 of 103 (78%) achieved complete remission with no significant differences between CNS+ and CNS- patients. Five-year disease-free survival and overall survival were found to be shorter in CNS+ patients than in those CNS- (18% vs 50%, P = .006 and 19% vs 46%, P = .02, respectively). In multivariate analysis, CNS status and age were found to affect independently overall survival. In conclusion, the incidence of CNS involvement in adult patients with newly diagnosed AML is higher than expected. Regardless of neurologic symptoms, it should always be searched at diagnosis; CSF samples should routinely be investigated by FCM since a certain proportion of CNS involvements might remain undetected if examination is exclusively CC based.

Acute Myeloid Leukemia With Central Nervous System Involvement in Children: Experience From the French Protocol Analysis ELAM02

Central nervous system (CNS) involvement at diagnosis of pediatric acute myeloid leukemia (AML) is not considered as an independent prognostic factor. This study describes the prognostic value of pediatric AML with CNS involvement at diagnosis. Pediatric patients were treated for de novo AML in the French multicenter trial ELAM02. Lumbar puncture was carried out in the first week, and the treatment was adapted to the CNS status. No patient received CNS radiotherapy. The patients were classified into 2 groups: CNS+ and CNS-. Of the 438 patients, 16% (n=70) had CNS involvement at diagnosis, and 29% showed clinical signs. The patients with CNS disease were younger (40% were below 2 y old), had a higher white blood cell count (median of 45 vs. 13 G/L), and had M4 and M5 morphologies. The complete remission rate was similar at 92.8% for CNS+ and 88.5% for CNS-. There was no significant difference between the CNS+ and the CNS- group in overall survival (76% and 71%, respectively) and event-free survival (57% and 52%, respectively). Regarding the occurrence of first relapse, the CNS+ group had a higher combined relapse rate of 26.1% compared with 10% for the CNS- group. The results indicate that CNS involvement at diagnosis of pediatric AML is not an independent prognostic factor. Triple intrathecal chemotherapy combined with high-dose intravenous cytarabine should be the first-line treatment for CNS disease.

Presenting features and imaging in childhood acute myeloid leukemia with central nervous system involvement

Central nervous system (CNS) involvement in childhood acute myeloid leukemia (AML) can manifest as leukemic cells in the cerebrospinal fluid, a solid CNS tumor, or as neurological symptoms. We evaluated the presenting symptoms and neuroimaging findings in 33 of 34 children with AML and CNS involvement at diagnosis in the period 2000-2012 in Sweden, Finland, and Denmark. Imaging was performed in 22 patients, of whom 16 had CNS-related symptoms. Seven patients, including all but two with facial palsy, had mastoid cell opacification, considered an incidental finding. The frequent involvement of the mastoid bone with facial palsy warrants evaluation in larger series.

Extramedullary leukemia in children with acute myeloid leukemia: A population-based cohort study from the Nordic Society of Pediatric Hematology and Oncology (NOPHO)

BACKGROUND

The prognostic significance of extramedullary leukemia (EML) in childhood acute myeloid leukemia is not clarified.

PROCEDURE

This population-based study included 315 children from the NOPHO-AML 2004 trial.

RESULTS

At diagnosis, 73 (23%) patients had EML: 39 (12%) had myeloid sarcoma, 22 (7%) had central nervous system disease, and 12 (4%) had both. EML was associated with young age (median age: 2.6 years), a high white blood cell count (median: 40 × 10⁹ /l), M5 morphology (40%), and 11q23/MLL (KMT2A) rearrangements (34%). No patient received involved field radiotherapy. Five-year event-free survival did not differ significantly between the EML and the non-EML patients (54% vs. 45%, P = 0.57), whereas 5-year overall survival (OS) was significantly lower in the EML group (64% vs. 73%, P = 0.04). The risk of induction death was significantly higher for EML patients (8% vs. 1%, P = 0.002). There was a trend toward a lower risk of relapse for EML patients (5-year cumulative incidence of relapse 33% vs. 49%, P = 0.16). Traumatic lumbar puncture did not adversely affect survival in this cohort.

CONCLUSIONS

EML was associated with increased risk of induction death impacting the OS. No patients relapsed at the primary site of the myeloid sarcoma despite management without radiotherapy.

RUNX1-RUNX1T1-positive acute myeloid leukaemia presenting as bilateral proptosis and multiple cranial nerve palsy

We describe a unique presentation of acute myeloid leukaemia (AML) with myeloid sarcoma (MS), manifested as proptosis with multiple cranial nerve palsies in a 9-year-old boy. MRI of the brain revealed multiple enhancing lesions and bilateral mastoiditis, in addition to sagittal sinus thrombosis. Peripheral blood smear demonstrated blasts showing Auer rods. Bone marrow examination confirmed the diagnosis of AML. PCR was positive for RUNX1-RUNX1T1. Neurological deficits improved with induction chemotherapy for AML. Extramedullary MS can present simultaneously with or antedate AML. Common genetic aberrations include t(8;21) and inv(16). Therapy is akin to AML. An effect of MS on survival outcomes is variable.

Initial Diagnostic Workup of Acute Leukemia: Guideline From the College of American Pathologists and the American Society of Hematology

CONTEXT

- A complete diagnosis of acute leukemia requires knowledge of clinical information combined with morphologic evaluation, immunophenotyping and karyotype analysis, and often, molecular genetic testing. Although many aspects of the workup for acute leukemia are well accepted, few guidelines have addressed the different aspects of the diagnostic evaluation of samples from patients suspected to have acute leukemia.

OBJECTIVE

- To develop a guideline for treating physicians and pathologists involved in the diagnostic and prognostic evaluation of new acute leukemia samples, including acute lymphoblastic leukemia, acute myeloid leukemia, and acute leukemias of ambiguous lineage.

DESIGN

- The College of American Pathologists and the American Society of Hematology convened a panel of experts in hematology and hematopathology to develop recommendations. A systematic evidence review was conducted to address 6 key questions. Recommendations were derived from strength of evidence, feedback received during the public comment period, and expert panel consensus.

RESULTS

- Twenty-seven guideline statements were established, which ranged from recommendations on what clinical and laboratory information should be available as part of the diagnostic and prognostic evaluation of acute leukemia samples to what types of testing should be performed routinely, with recommendations on where such testing should be performed and how the results should be reported.

CONCLUSIONS

- The guideline provides a framework for the multiple steps, including laboratory testing, in the evaluation of acute leukemia samples. Some aspects of the guideline, especially molecular genetic testing in acute leukemia, are rapidly changing with new supportive literature, which will require on-going updates for the guideline to remain relevant.

Extramedullary Disease in Adult Acute Myeloid Leukemia Is Common but Lacks Independent Significance: Analysis of Patients in ECOG-ACRIN Cancer Research Group Trials, 1980-2008

Purpose Extramedullary disease (EMD) at diagnosis in patients with acute myeloid leukemia (AML) has been recognized for decades. Reported herein are results from a large study of patients with AML who were treated in consecutive ECOG-ACRIN Cancer Research Group frontline clinical trials in an attempt to define the incidence and clinical implications of EMD. Methods Patients with newly diagnosed AML, age 15 years and older, who were treated in 11 clinical trials, were studied to identify EMD, as defined by physical examination, laboratory findings, and imaging results. Results Of the 3,522 patients enrolled, 282 were excluded, including patients with acute promyelocytic leukemia, incorrect diagnosis, or no adequate assessment of EMD at baseline. The overall incidence of EMD was 23.7%. The sites involved were: lymph nodes (11.5%), spleen (7.3%), liver (5.3%), skin (4.5%), gingiva (4.4%), and CNS (1.1%). Most patients (65.3%) had only one site of EMD, 20.9% had two sites, 9.5% had three sites, and 3.4% had four sites. The median overall survival was 1.035 years. In univariable analysis, the presence of any EMD ( P = .005), skin involvement ( P = .002), spleen ( P < .001), and liver ( P < .001), but not CNS ( P = .34), nodal involvement ( P = .94), and gingival hypertrophy ( P = .24), was associated with a shorter overall survival. In contrast, in multivariable analysis, adjusted for known prognostic factors such as cytogenetic risk and WBC count, neither the presence of EMD nor the number of specific sites of EMD were independently prognostic. Conclusion This large study demonstrates that EMD at any site is common but is not an independent prognostic factor. Treatment decisions for patients with EMD should be made on the basis of recognized AML prognostic factors, irrespective of the presence of EMD.

Central hypothyroidism in a pediatric case of primary acute monoblastic leukemia with central nervous system infiltration: A case report

RATIONALE

Central nervous system (CNS) leukemia is a frequent diagnosis in pediatric acute myeloblastic leukemia (AML) and includes neural symptoms. However, CNS leukemia is rarely associated with central hypsothyroidism.

PATIENT CONCERNS AND DIAGNOSES

A 2-year-old female with AML with MLL rearrangement presented with CNS infiltration. Laboratory tests suggested the presence of central hypothyroidism (thyroid-stimulating hormone [TSH]: 0.48 mIU/ml, normal range 0.7-6.4 mIU/ml; serum free thyroxine [FT4]: 0.62 ng/dl, normal range 0.8-2.2 ng/dl; free triiodothyronine: 1.57 pg/ml, normal range 2.7-5.6 pg/ml). Magnetic resonance imaging detected no lesions in the hypothalamus, pituitary, or thyroid.

INTERVENTIONS AND OUTCOMES

Levothyroxine (2.5 mg/kg/day) was administered together with chemotherapy and intrathecal injection of methotrexate, cytarabine, and hydrocortisone into the cerebrospinal fluid. The FT4 concentration increased after levothyroxine treatment, but later decreased after relapse of CNS leukemia. The TSH concentrations remained low. After remission of CNS leukemia, the TSH and FT4 concentrations quickly recovered to their normal ranges.

LESSONS

We believe that the CNS leukemia directly affected TSH and thyroid hormone secretion in our patient.

Unravelling chloroma: review of imaging findings

Chloroma refers to the extramedullary proliferation of immature myeloid precursors occurring in a gamut of myeloproliferative and myelodysplastic conditions; acute myeloid leukaemia being the commonest. With non-specific clinical and imaging manifestations, it runs a high risk of misdiagnosis which may significantly affect the outcome of an otherwise treatable lesion. Also with these lesions heralding impending blast crises, awareness of the imaging findings becomes imperative. Imaging not only helps raise the suspicion but also guides further confirmation by demonstration of specific immunohistochemistry markers, ensuring timely institution of chemotherapy. In general, solid enhancing lesions in any haematological disorder could be chloromas, especially if multifocal with mass effect.

Symptomatic central nervous system involvement in adult patients with acute myeloid leukemia

INTRODUCTION

Acute myeloid leukemia (AML) rarely involves the central nervous system (CNS). Little is known about the clinical course in adult AML patients since most studies examined pediatric patients. Therefore, this study analyzed the data of patients treated in three prospective trials of the "Study Alliance Leukemia" (SAL) study group for CNS involvement.

METHODS

In all, 3,261 AML patients included in the prospective AML96, AML2003, and AML60+ trials of the SAL study group were analyzed. Symptomatic patients underwent cerebrospinal fluid (CSF) puncture and CNS involvement was diagnosed depending on morphology and/or flow cytometry of the CSF. Cytogenetic, molecular, clinical, and laboratory parameters were analyzed in order to identify risk factors.

RESULTS

A total of 55 patients had proven symptomatic CNS involvement. Significantly more patients revealed CNS involvement at relapse (34 patients, 2.9%) compared with first diagnosis (21 patients, 0.6%), p<0.001. CNS involvement at initial diagnosis had a significantly higher frequency in patients with complex aberrant karyotypes, high serum lactate dehydrogenase activity, French-American-British M5 subtype, FLT3-internal tandem duplication (ITD) mutations alone, and co-occurrence of a FLT3-ITD and NPM1 mutation. Furthermore, AML patients with CNS involvement at diagnosis had an inferior outcome compared with patients without CNS involvement even if treated with intrathecal chemotherapy with an overall survival of 11% versus 30% at 5 years, p=0.004.

CONCLUSION

This study analyzed the largest data set of adult AML patients with proven CNS involvement reported so far. The data demonstrated very low prevalence of CNS involvement at initial diagnosis in adult patients with AML, and described new risk factors. In patients with risk factors, intense diagnostic and treatment strategies should be employed in the future.

Myeloid sarcoma in children - diagnostic and therapeutic difficulties

Myeloid sarcoma (MS) is a malignant extramedullary tumour, which consists of immature cells of myeloid origin. It may occur de novo, concurrently or precede the diagnosis of acute myeloid leukemia (AML), myelodysplastic syndrome (MDS) or chronic myeloid leukemia (CML). MS can also be a manifestation of the relapse of the disease. The more frequent sites of involvement are the skin, orbit, bone, periosteum, lymph nodes, gastrointestinal tract, soft tissue, central nervous system and testis. Because of its different localization and symptoms, and the lack of diagnostics algorithm, myeloid sarcoma is a real diagnostic challenge, in particular in patients without initial bone marrow involvement. The correct diagnosis of MS is important for adequate therapy, which is often delayed because of a high misdiagnosis rate. In the paper, the role of immunohistochemistry, cytogenetic and molecular genetic analyses is emphasized as well as the breadth of unclear aspects of this disorder in children.

Do Not Forget the Glycophorin A: An Unusual Case of Myeloid Sarcoma

Acute erythroid leukemia is rare, with isolated reports on presentation as an extramedullary tumor mass (myeloid sarcoma). We describe a case of pure erythroid leukemia presenting as an orbital mass in a 1-year, 9-month-old girl. This is only the second case described in a child. Tissue biopsy of the tumor mass showed medium-sized cells that were glycophorin A positive and negative with conventional myeloid markers. Flow cytometry, bone marrow aspirate, and trephine confirmed the diagnosis of pure erythroid leukemia.

Higher EZH2 expression is associated with extramedullary infiltration in acute myeloid leukemia

Accumulating evidence indicates that enhancer of zeste homolog 2 (EZH2) promotes the metastatic ability of solid tumors, but the role of EZH2 in extramedullary infiltration (EMI) in acute myeloid leukemia (AML) has not been thoroughly explored. In the present study, we investigated the possible association between EZH2 and EMI. We found that the messenger RNA (mRNA) and protein expression levels of EZH2 in AML patients were both significantly higher than in idiopathic thrombocytopenic purpura (ITP) patients. Furthermore, a positive correlation between EZH2 mRNA expression and percentage of peripheral blood blasts wa s found in AML patients (r = 0.404, p = 0.009). The migratory capacities of Kasumi-1 and HL-60, which both show a high level of EZH2 expression, were markedly higher than those of U937 and KG-1α. In contrast, silencing of EZH2 resulted in reduction in proliferation and migration ability and an increase in apoptosis. The latter observation was accompanied by reduced expression of associated proteins p-ERK, p-cmyc, and matrix metalloproteinase 2 (MMP-2) and an increase in epithelial cadherin (E-cadherin). These data suggest that higher expression of EZH2 may be associated with extramedullary infiltration in acute myeloid leukemia and affect pathogenesis via activation of the p-ERK/p-cmyc/MMP-2 and E-cadherin signaling pathways.

Risk factors and clinical outcomes of acute myeloid leukaemia with central nervous system involvement in adults

BACKGROUND

Acute myeloid leukaemia (AML) with central nervous system (CNS) involvement in adults is uncommon, and studies of this subject are scant.

METHODS

We conducted a retrospective study to investigate the clinical aspects, cytogenetic abnormalities, molecular gene mutations and outcomes of adult AML patients with CNS involvement. Three hundred and ninety-five patients with newly diagnosed AML were reviewed.

RESULTS

Twenty (5.1%) patients had CNS involvement, including 7 (1.8%) with initial CNS disease and 4 (1%) who suffered an isolated CNS relapse. The patients with CNS involvement were younger, had higher leukocyte, platelet, and peripheral blast cell counts, FAB M4 morphology, and chromosome translocations involving 11q23 (11q23 abnormalities) more frequently than did the patients without CNS involvement. No differences in sex, haemoglobin levels, serum LDH levels, immunophenotype of leukaemia cells, or molecular gene mutations were observed between the two groups. Multivariate analyses showed that age ≤ 45 years (OR, 5.933; 95% CI, 1.82 to 19.343), leukocyte counts ≥ 50,000/μl (OR, 3.136; 95% CI, 1.083 to 9.078), and the presence of 11q23 abnormalities (OR, 5.548; 95% CI, 1.208 to 25.489) were significant predictors of CNS involvement. Patients with initial CNS disease had 5-year overall survival and relapse-free survival rates that were similar to those without initial CNS disease. However, three of four patients who suffered an isolated CNS relapse died, and their prognosis was as poor as that of patients who suffered a bone marrow relapse.

CONCLUSION

CNS involvement in adult patients with AML is rare. Three significant risk factors for CNS involvement including age ≤ 45 years, leukocyte counts ≥ 50,000/μl and the presence of 11q23 abnormalities were identified in this study. Future investigations to determine whether adult AML patients having these specific risk factors would benefit from CNS prophylactic therapy are necessary.