Current treatment strategies for measurable residual disease in patients with acute myeloid leukemia

Patients with acute myeloid leukemia (AML) who achieve a morphologic complete remission still can have measurable residual disease (MRD) detected by multiparametric flow cytometry, molecular methods, or cytogenetics. Such patients with MRD have a high risk of disease recurrence over a short timeframe, but optimal treatment strategies are unknown. Outcomes with conventional treatment, including allogeneic hematopoietic cell transplantation, are worse than those for patients without MRD. Herein, the authors review current strategies, including novel clinical trials, targeted toward patients with MRD.     

Inflammatory biomarkers,geriatric assessment,and treatment outcomes in acute myeloid leukemia

ObjectivesTo investigate changes in inflammatory biomarkers during induction therapy for older adults with acute myeloid leukemia (AML) and their associations with geriatric assessment (GA) measures and outcomes.MethodsThis was a single institution ancillary study to a prospective observational study (N = 20 consecutive adults aged ≥60 with newly diagnosed AML who received induction chemotherapy). Biomarkers (Interleukin-6 [IL-6], IL-6 soluble receptor [IL-6 sR], tumor necrosis factor alpha [TNFα], TNFα soluble receptor 1 [TNFα sR1], interleukin-3 [IL-3], C-reactive protein [CRP]) were collected at start of induction, weekly for three weeks, and post-induction and were compared over time using paired t-tests. GA was administered at baseline and post-induction, and correlated with biomarker levels using Spearman correlations. Survival was estimated using Kaplan-Meier and compared by categorized biomarker level using Wilcoxon tests.ResultsBiomarker levels were stable during induction, except for CRP and IL-6 sR. Declines in objectively measured physical function [Short Physical Performance Battery (SPPB); r = 0.71, p < 0.01] and increases in self-reported limitation in instrumental activities of daily living (r = 0.81, p < 0.01) were correlated with increased TNFα sR1. Declines in SPPB were correlated with increased CRP (r = −0.73, p < 0.01). Improvement in depression was correlated with increased IL-6 sR (r = −0.59 p = 0.02). Survival was shorter in those with baseline TNFα or CRP levels above the median (6.1 vs. 40.2 months and 5.5 vs. 27.6 months respectively, p = 0.04 for both).ConclusionAmong older adults with AML, the relationships between TNFα sR1, CRP, and IL-6 sR with change in physical and emotional health during treatment warrants further investigation.     

急性髓系白血病患者微小残留病检测的研究进展

  近年来,随着多参数流式细胞术（MFC）及荧光实时定量聚合酶链反应（RQ-PCR）检测手段的进步,两者越来越多地被应用于急性髓系白血病（AML）患者微小残留病（MRD）的检测。通过这些更加客观、敏感及特异的检测方法的应用,将更有助于评估AML的疗效及监测早期复发,并可据此调整治疗策略。     

Chemotherapy for patients with acute myeloid leukemia in first remission

Although the majority of patients with acute myeloid leukemia (AML) achieve a complete remission with induction chemotherapy, most will ultimately relapse. Therefore, the optimal postremission therapy for AML remains to be defined, and further improvements in treatment strategies are required. Clinical trials have demonstrated that early intensive consolidation therapy with high-dose cytarabine can produce prolonged responses in up to 40% of patients in remission after standard induction therapy. Equally, however, it has been shown that high-dose cytarabine used in induction therapy can deliver equivalent long-term results. Autologous and allogeneic stem cell transplantation in first remission are also valid alternatives, but the value of low-dose maintenance treatment seems confined to acute promyelocytic leukemia. Further improvement in the treatment of AML is likely to depend on the development of new strategies, such as molecularly targeted or immune therapies.     

Postremission therapy for acute myeloid leukemia in the first remission

The medical records of 99 patients with acute myeloid leukemia (AML; except AML, M3) in the first remission from 1995 to 2004 were retrospectively reviewed. When they achieved complete remission, at first complete remission (CR1), patients received allogeneic (n = 23), autologous hematopoietic stem cell transplantation (HSCT) (n = 35), or intensive chemotherapy (n = 41) according to prognostic factors and donor availability. There was an advantage in terms of event-free survival (EFS, p = 0.0001) and overall survival (OS, p = 0.0002) with HSCT as compared to those of intensive chemotherapy. However, the EFS and OS were not different between allogeneic HSCT and autologous HSCT. In high-risk patients, the EFS and OS of allogenic or autologous HSCT group were higher compared with those in the intensive chemotherapy group (p < 0.01). However, there was no difference between allogeneic HSCT and autologous HSCT in terms of EFS and OS. In the intermediate- or low-risk group, there was no significant difference in the outcome according to the postremission modalities.     

Detection of minimal residual disease in acute myeloid leukemia

Acute myeloid leukemia (AML) is a curable malignancy, but its cure rate remains disappointingly low. Accurate quantitation of residual AML cells would allow individualization of therapy and thereby increase the likelihood of cure for each patient. Techniques that are being studied for residual disease detection include molecular assays for abnormalities that are present in subsets of AML patients, and multiparameter flow cytometry, which has broader applicability. Although significant advances have been made in the development of assays for monitoring residual disease, and particularly in techniques for molecular quantitation, additional refinement and validation are needed before these assays can be applied routinely in clinical management.     

Monitoring of minimal residual disease in acute myeloid leukemia

Two highly sensitive methods, multiparameter flow cytometry (MFC) and real-time quantitative PCR (RQ-PCR), are increasingly used to monitor minimal residual disease (MRD) and to guide risk-adapted management in acute myeloid leukemia (AML). An independent prognostic impact has been demonstrated for MRD levels obtained by both methods. MFC has been found particularly useful for assessment of early clearance of malignant cells and after consolidation therapy. At the latter checkpoint, MRD levels quantified by RQ-PCR in AML with fusion genes also have the strongest prognostic power. In addition, highly predictive initial expression levels have been identified by RQ-PCR. Both methods are capable of early detection of relapse. Through the use of all available markers including NPM1 mutations and FLT3 mutations in addition to fusion genes, RQ-PCR-based MRD assessment is possible in more than half of patients, whereas MFC is applicable to most AML cases. With a sensitivity of 10(-4) (PML-RARA) to 10(-7) (patient-specific primers, FLT3 and NPM1 mutations), RQ-PCR is more sensitive in most cases. Large clinical trials will determine the exact role and place of immunologic and RQ-PCR-based monitoring of MRD in the therapy of patients with AML.     

Detection of minimal residual disease in acute myeloid leukemia.

The distinction of clonogenic leukemic cells (CFU-L) and normal myeloid progenitors (GM-CFU) is a problem because both types of cells respond to the same growth factors and their clones resemble each other morphologically in culture. We investigated by means of an indirect enzyme-immunoassay the expression of "early" and "late" differentiation markers on bone marrow cell suspensions, as well as on agar clones in 18 cases of newly diagnosed acute myeloid leukemia (AML) as compared with 13 normal controls. Uncultured AML cells carried only low amounts of "late" myeloid differentiation antigen (CD15) but expressed nearly normal levels when cultured in agar with colony-stimulating factor (CSF). In contrast to normal bone marrow, AML cells were strongly reactive with "early" differentiation markers (CD10, CD20, CD34) and remained so during culture. Normal and leukemic agar clones could be specifically distinguished by CD20- and CD34 antibodies. By means of a double marker technique, it could be shown that "late" myeloid differentiation markers (CD15) and "early" markers (CD10, CD20, CD34) were coexpressed on the same cells only in AML but not in normal bone marrow. Leukemic clones were identified by phenotyping of agar clones in 17 of 19 cases investigated during complete clinical remission (CR) of the disease. A formal proof of the leukemic origin of CD20/CD34 positive clones grown in CR was made possible in four cases either by Southern blot analysis or by a cytogenetic marker. These results demonstrate that AML cells can partially differentiate in vitro in the presence of CSF. A distinction of AML from normal clones, however, is possible by their reactivity with "early" differentiation markers, because this is maintained under the differentiating influence of CSF. The technique described here identifies residual leukemic clones in the majority of AML in CR, which persist at a constant rate and increase 6 months before cytological relapse.     

Prognostic value of measurable residual disease monitoring by next-generation sequencing before and after allogeneic hematopoietic cell transplantation in acute myeloid leukemia

Given limited studies on next-generation sequencing-based measurable residual disease (NGS-MRD) in acute myeloid leukemia (AML) patients after allogeneic hematopoietic stem cell transplantation (allo-HSCT), we longitudinally collected samples before and after allo-HSCT from two independent prospective cohorts (n = 132) and investigated the prognostic impact of amplicon-based NGS assessment. Persistent mutations were detected pre-HSCT (43%) and 1 month after HSCT (post-HSCT-1m, 20%). All persistent mutations at both pre-HSCT and post-HSCT-1m were significantly associated with post-transplant relapse and worse overall survival. Changes in MRD status from pre-HSCT to post-HSCT-1m indicated a higher risk for relapse and death. Isolated detectable mutations in genes associated with clonal hematopoiesis were also significant predictors of post-transplant relapse. The optimal time point of NGS-MRD assessment depended on the conditioning intensity (pre-HSCT for myeloablative conditioning and post-HSCT-1m for reduced-intensity conditioning). Serial NGS-MRD monitoring revealed that most residual clones at both pre-HSCT and post-HSCT-1m in patients who never relapsed disappeared after allo-HSCT. Reappearance of mutant clones before overt relapse was detected by the NGS-MRD assay. Taken together, NGS-MRD detection has a prognostic value at both pre-HSCT and post-HSCT-1m, regardless of the mutation type, depending on the conditioning intensity. Serial NGS-MRD monitoring was feasible to compensate for the limited performance of the NGS-MRD assay.Subject terms: Cancer genomics, Acute myeloid leukaemia, Translational research, Acute myeloid leukaemia     

Spontaneous remission of acute myeloid leukemia associated with GnRH agonist treatment

Spontaneous remission of acute myeloid leukemia (AML) in adults is a rare but well documented phenomenon. This study reports on a 64-year-old male patient with acute myelogenous leukemia (AML-M4, according to the French-American-British classification) that was developed on a background of chronic myelomonocytic leukemia (CMML) and then underwent remission after treatment with the gonadotropin-releasing hormone agonist (GnRH agonist) triptorelin for presumed prostate cancer. Remission persisted for at least 4 years before the patient was lost to follow-up. To the author' knowledge, this is the first report of remission in an AML-M4 case associated with hormone manipulation. Possible mechanisms of this phenomenon are discussed.     

G-CSF-induced remission in two cases of acute myeloid leukemia

We report on two elderly patients with newly diagnosed acute myeloid leukemia (AML) who were treated in palliative intention because of comorbidities and intermediate or poor risk cytogenetics. Both received G-CSF to reduce the risk of infection related to neutropenia. Interestingly, one patient achieved a full hematological remission and the other a peripheral remission with dramatic reduction of the bone marrow blast count. Although a direct therapeutic effect of myeloid growth factors seems to be unusual in AML, the use of G-CSF or GM-CSF may be recommended in patients such as elderly patients who are not suited for intensive chemotherapy.     

Measurable residual disease status and outcome of transplant in acute myeloid leukemia in second complete remission: a study by the acute leukemia working party of the EBMT

Measurable residual disease (MRD) prior to hematopoietic cell transplant (HCT) for acute myeloid leukemia (AML) in first complete morphological remission (CR1) is an independent predictor of outcome, but few studies address CR2. This analysis by the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation registry assessed HCT outcomes by declared MRD status in a cohort of 1042 adult patients with AML CR2 at HCT. Patients were transplanted 2006–2016 from human leukocyte antigen (HLA) matched siblings (n = 719) or HLA 10/10 matched unrelated donors (n = 293). Conditioning was myeloablative (n = 610) or reduced-intensity (n = 432) and 566 patients (54%) had in-vivo T cell depletion. At HCT, 749 patients (72%) were MRD negative (MRD NEG) and 293 (28%) were MRD positive (MRD POS). Time from diagnosis to HCT was longer in MRD NEG than MRD POS patients (18 vs. 16 months (P < 0.001). Two-year relapse rates were 24% (95% CI, 21–28) and 40% (95% CI, 34–46) in MRD NEG and MRD POS groups (P < 0.001), respectively. Leukemia-free survival (LFS) was 57% (53–61) and 46% (40–52%), respectively (P = 0.001), but there was no difference in terms of overall survival. Prognostic factors for relapse and LFS were MRD NEG status, good risk cytogenetics, and longer time from diagnosis to HCT. In-vivo T cell depletion predicted relapse.Subject terms: Risk factors, Acute myeloid leukaemia     

Serial assessment of measurable residual disease in medulloblastoma liquid biopsies

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Potential cure of acute myeloid leukemia : analysis of 1069 consecutive patients in first complete remission

BACKGROUND: Potential cure of acute myeloid leukemia (AML) is now a widely accepted idea, but it is uncertain whether there is heterogeneity in the failure rate in patients once they have been in complete remission (CR) for various periods of time. METHODS: The long-term outcomes were analyzed in 1069 consecutive AML patients in first CR who were diagnosed and treated at the University of Texas M. D. Anderson Cancer Center between 1991 and 2003. RESULTS.: The failure rates as yearly risk of treatment failure were 69.1 in the first year, 37.7 in the second year, 17.0 in the third year, 7.6 in the fourth year, and 6.6 in the fifth year, suggesting that 3 years from the CR date is a convenient time to consider patients potentially cured. The effect of cytogenetics on relapse-free survival (RFS) remained constant throughout the first 3 years, whereas the effect of age increased with time. The probability of RFS for patients alive without disease recurrence at 3 years was 84.0% at 6 years. When the interaction between age and cytogenetics was examined for these patients, the outcomes of those with favorable cytogenetics were found to be excellent regardless of age. However, in the intermediate cytogenetic group, although patients aged <60 years had excellent outcomes, those aged > or =60 years were found to be at a substantial risk of disease recurrence even after 3 years of CR, with a 6-year RFS rate of 56.5%. There were only 6 patients with adverse cytogenetics in this cohort. CONCLUSIONS: The results of the current study demonstrate that the risk of treatment failure differs over time according to a combination of cytogenetics and age.     

New approaches for the detection of minimal residual disease in acute myeloid leukemia

The detection of minimal residual disease (MRD) in patients with acute leukemia has been studied for about 15 years by different groups in both the United States and Europe. It has been found that MRD detection can be performed using molecular and immunophenotypic aberrancies that are present in the leukemic clone at diagnosis and not in normal bone marrow. When performing MRD assessments after chemotherapy, it is possible to identify patients at risk for relapse. This review is not an overview of all MRD studies, but rather discusses the possibilities for optimizing MRD detection, the use of flow cytometry versus polymerase chain reaction techniques, and the implications for future patient treatment. When informative, we compare literature on MRD in acute myeloid leukemia (AML) with information from MRD studies in acute lymphoblastic leukemia. Finally, we address the promising detection of AML stem cells, the likely cells of origin in AML, for prediction of clinical outcome and guidance of future therapies.     

Geriatric assessment in older patients with acute myeloid leukemia: A retrospective study of associated treatment and outcomes

We explored whether geriatric assessment variables predicted mortality in addition to known prognostic factors in 101 patients aged ≥65 with newly diagnosed AML. Baseline comorbidity score (HR = 1.92; 95%CI 1.18–3.11), difficulty with strenuous activity (HR = 2.18; 95%CI 1.19–4.00), and pain (HR = 2.17; 95%CI 1.19–3.97) were independent prognostic factors for greater risk of death in a multivariable model that included cytogenetic risk group. They remained independent predictors in the subset of patients with baseline ECOG PS 0-1. Our results support the use of geriatric assessment to better predict prognosis in older patients with AML, even among those with excellent functional status.     

Multidimensional flow cytometry for detection of minimal residual disease in acute myeloid leukemia

The term minimal residual disease (MRD) describes the situation in which, after chemotherapy for acute leukemia (AL), a morphologically normal bone marrow (BM) can still harbor a relevant amount of residual malignant cells. Several techniques are now amenable to investigate MRD, and all together they have designated a new era in which a re-definition of the current criteria of complete remission (CR) is required. Depending upon the measured level of MRD we can distinguish a variety of clinical situations ranging from a potentially cured disease to short-term remission. In the context of this spectrum of conditions there would be room for different therapeutic strategies ranging from no further therapy to pre-emptive therapy to treat early relapses (immunologic and/or molecular relapses). This review will focus on the state of art of MRD detection in acute myeloid leukemia (AML) using multidimensional flow cytometry (MFC), and will cover the laboratory and clinical aspects of this approach.     

Monitoring of minimal residual disease in acute myeloid leukemia: methods and best applications

Posttherapy minimal residual disease assessment in acute myeloid leukemia is an important prognostic indicator as well as a potential early surrogate measure of therapeutic effectiveness. The goal of this brief review is to discuss the broad classes of targets for molecular diagnostic assays, with specific examples of each, and to describe the analytic approach to flow cytometry testing for minimal residual disease in acute myeloid leukemia. Several of the most significant recent contributions to this field are highlighted.