Newly diagnosed acute lymphoblastic leukemia in China (II): prognosis related to genetic abnormalities in a series of 1091 cases

Causes of death and treatment-related mortality in newly diagnosed childhood acute lymphoblastic leukemia treatment with Chinese Children's Cancer Group study ALL-2015

To investigate the possible risk factors for death at post-treatment in children with acute lymphoblastic leukemia (ALL). A multivariate competing risk analysis was performed to retrospectively analyze the data of children with ALL who died after treatment with CCCG-ALL-2015 in China and to determine the possible risk factors for death at post-treatment in children with ALL. Age at the first diagnosis of ≥10 years; final risk level of high-risk; D19 minimal residual disease (MRD) (≥0.01%) and D46 MRD (≥0.01%); genetic abnormalities, such as KMT2A-rearrangement, c-Myc rearrangement, and PDGFRB rearrangement; and the presence of CNS3 (all P values, <0.05) were identified as independent risk factors, whereas the risk level at the first diagnosis of low-risk (LR) and ETV6::RUNX1 positivity was considered as independent protective factors of death in children with ALL. Among the 471 cases of death, 45 cases were treated with CCCG-ALL-2015 only, and 163 (34.61%) were treatment-related, with 62.42% due to severe infections. 55.83% of treatment-related mortality (TRM) occurred in the early phase of treatment (induction phase). TRM has a significant impact on the overall survival of pediatric patients with ALL. Moreover, the CCCG-ALL-2015 regimen has a better safety profile for treating children with ALL, with rates close to those in developed countries (registration number: ChiCTR-IPR-14005706; date of registration: June 4, 2014).

Hematological, clinical, immunophenotypic characterization, and treatment outcomes of prognostically significant genetic subtypes of B-lineage acute lymphoblastic leukemia: A report of 1021 patients from India

BACKGROUND

The published literature on hematological, clinical, flowcytometric-immunophenotyping, and minimal residual disease outcomes of the prognostically important genetic subtypes of acute lymphoblastic leukemia (ALL) is scarce from low-income countries. For newer classifications such as BCR::ABL1-like ALLs, the scarcity of patient-level data is even more pronounced.

METHODS

The authors performed comprehensive detection of recurrent gene fusions and BCR::ABL1-like ALL cases followed by immunophenotypic profiling and obtained clinical outcome parameters for a large cohort (n = 1021) of patients from India. This cohort included a significant number of patients with BCR::ABL1-like ALL subtype and other genetic subtypes of ALL.

RESULTS

Patients with BCR::ABL1-positive and BCR::ABL1-like ALL were significantly older, had male preponderance, and expressed a higher white blood cell count than BCR::ABL1-negative cases (p < .05). Logistic regression modeling of B-lineage-ALL (B-ALL) subtypes revealed that cluster of differentiation (CD)36 is a strong statistically significant predictive marker of BCR::ABL1-like ALL (p < .05). Furthermore, patients with BCR::ABL1-like ALLs show a significantly higher frequency of CD36 expression compared to BCR::ABL1-negative ALLs (p < .05). In terms of clinical symptoms, lymphadenopathy is a strong statistically significant predictive marker in BCR::ABL1-like ALLs compared to BCR::ABL1-negative ALL cases (p < .05). In terms of treatment outcomes, minimal residual disease (MRD) positivity in BCR::ABL1-positive ALL cases were statistically significant (p < .05), and BCR::ABL1-like ALL cases had high MRD-positivity as compared to BCR::ABL1-negative ALL cases but did not show statistical significance.

CONCLUSIONS

The findings evince the use of novel therapies and personalized treatment regimens to improve the overall survival of the newer incorporated entities in B-ALLs. This is the first report characterizing the hematological, clinical, flowcytometric-immunophenotyping, and minimal residual disease outcomes of the prognostically significant subtypes of ALLs in patients from India.

PLAIN LANGUAGE SUMMARY

Characterizing the hematological, clinical, flowcytometric-immunophenotyping, and minimal residual disease outcomes of the prognostically significant subtypes (n = 1021) of acute lymphoblastic leukemia (ALLs) in patients from India. We have made two independent logistic regression models of cluster of differentiation (CD) markers and clinical symptoms to differentiate prognostically significant subtypes of ALLs. Logistic regression analysis of CD markers revealed CD36 as a strong predictor in BCR::ABL1-like ALL cases compared to BCR::ABL1-negative ALL cases. Logistic regression analysis of clinical symptoms revealed lymphadenopathy significantly predicts BCR::ABL1-like ALLs (p < .05). In terms of treatment outcomes, BCR::ABL1-positive ALL had statistically significant minimal residual disease (MRD) (p < .05), and BCR::ABL1-like ALL cases had high MRD-positivity but did not show statistical significance as compared to BCR::ABL1-negative ALLs.

Dominant-negative type of IKZF1 deletion showed a favorable prognosis in adult B-cell acute lymphoblastic leukemia

IKZF1 deletion is a recurrent genomic alteration in B-cell acute lymphoblastic leukemia (B-ALL) and is divided into dominant-negative (DN) and loss of function (LOF) deletions. The prognostic impact of each deletion has not been fully elucidated. We retrospectively analyzed 117 patients with adult B-ALL including 60 patients with BCR::ABL1-positive B-ALL and 57 patients with BCR::ABL1-negative B-ALL by the fluorescence in situ hybridization (FISH) method for IKZF1 deletion and multiplex PCR for the 4 most common IKZF1 deletions (∆4-7, ∆2-7, ∆2-8, and ∆4-8). Samples, in which IKZF1 deletion was detected by FISH but a specific type of deletion was not identified by the PCR, were categorized as "other." Patients were classified into a DN group that had at least 1 allele of ∆4-7 (n = 23), LOF and other group (n = 40), and wildtype group (n = 54). DN type IKZF1 deletions were found in 33.3% of BCR::ABL1-positive cases and 5.2% of BCR::ABL1-negative cases. LOF and other type IKZF1 deletions were found in 43.4% of BCR::ABL1-positive cases and 24.6% of BCR::ABL1-negative cases. Patients with the DN group showed significantly higher overall survival (OS) than that of the LOF and other and WT groups (P = 0.011). Multivariate analysis including age, WBC counts, complex karyotype, and DN type IKZF1 deletion showed that the DN type of IKZF1 deletion (HR = 0.22, P = 0.013) had a positive impact and age ≥ 65 (HR = 1.92, P = 0.029) had a negative impact on OS. The prognostic impact of IKZF1 deletion depends on the type of deletion and DN type of IKZF1 deletion showed better prognosis in adult B-ALL patients.Clinical trial registration This study was part of a prospective observational study (Hokkaido Leukemia Net, UMIN000048611). It was conducted in compliance with ethical principles based on the Helsinki Declaration and was approved by the institutional review board of Hokkaido University Hospital (#015-0344).

'Evaluation of adverse prognostic gene alterations & MRD positivity in BCR::ABL1-like B-lineage acute lymphoblastic leukaemia patients, in a resource-constrained setting

BACKGROUND

Early detection of BCR::ABL1-like ALL could impact treatment management and improve the overall survival/outcome. BCR::ABL1-like ALL cases are characterised by diverse genetic alterations activating cytokine receptors and kinase signalling. Its detection is still an unmet need in low-middle-income countries due to the unavailability of a patented TLDA assay.

METHODS

This study's rationale is to identify BCR::ABL1-like ALLs using the PHi-RACE classifier, followed by the characterisation of underlying adverse genetic alterations in recurrent gene abnormalities negative (RGAneg) B-ALLs (n = 108).

RESULTS

We identified 34.25% (37/108) BCR::ABL1-like ALLs using PHi-RACE classifier, characterised by TSLPR/CRLF2 expression (11.58%), IKZF1 (Δ4-7) deletion (18.9%) and chimeric gene fusions (34.61%). In overexpressed TSLPR/CRLF2 BCR::ABL1-like ALLs, we identified 33.33% (1/3) CRLF2::IGH and 33.33% (1/3) EPOR::IGH rearrangements with concomitant JAK2 mutation R683S (50%). We identified 18.91% CD13 (P = 0.02) and 27.02% CD33 (P = 0.05) aberrant myeloid markers positivity, which was significantly higher in BCR::ABL1-like ALLs compared to non-BCR::ABL1-like ALLs. MRD positivity was considerably higher (40% in BCR::ABL1-like vs. 19.29% in non-BCR::ABL1-like ALLs).

CONCLUSIONS

With this practical approach, we reported a high incidence of BCR::ABL1-like ALLs, and a lower frequency of CRLF2 alteration & associated CGFs. Recognising this entity, early at diagnosis is crucial to optimise personalised treatment strategies.

Ectopic expression of a combination of 5 genes detects high risk forms of T-cell acute lymphoblastic leukemia

BACKGROUND

T cell acute lymphoblastic leukemia (T-ALL) defines a group of hematological malignancies with heterogeneous aggressiveness and highly variable outcome, making therapeutic decisions a challenging task. We tried to discover new predictive model for T-ALL before treatment by using a specific pipeline designed to discover aberrantly active gene.

RESULTS

The expression of 18 genes was significantly associated with shorter survival, including ACTRT2, GOT1L1, SPATA45, TOPAZ1 and ZPBP (5-GEC), which were used as a basis to design a prognostic classifier for T-ALL patients. The molecular characterization of the 5-GEC positive T-ALL unveiled specific characteristics inherent to the most aggressive T leukemic cells, including a drastic shut-down of genes located on the mitochondrial genome and an upregulation of histone genes, the latter characterizing high risk forms in adult patients. These cases fail to respond to the induction treatment, since 5-GEC either predicted positive minimal residual disease (MRD) or a short-term relapse in MRD negative patients.

CONCLUSION

Overall, our investigations led to the discovery of a homogenous group of leukemic cells with profound alterations of their biology. It also resulted in an accurate predictive tool that could significantly improve the management of T-ALL patients.

Ikaros Proteins in Tumor: Current Perspectives and New Developments

Ikaros is a zinc finger transcription factor (TF) of the Krüppel family member, which significantly regulates normal lymphopoiesis and tumorigenesis. Ikaros can directly initiate or suppress tumor suppressors or oncogenes, consequently regulating the survival and proliferation of cancer cells. Over recent decades, a series of studies have been devoted to exploring and clarifying the relationship between Ikaros and associated tumors. Therapeutic strategies targeting Ikaros have shown promising therapeutic effects in both pre-clinical and clinical trials. Nevertheless, the increasingly prominent problem of drug resistance targeted to Ikaros and its analog is gradually appearing in our field of vision. This article reviews the role of Ikaros in tumorigenesis, the mechanism of drug resistance, the progress of targeting Ikaros in both pre-clinical and clinical trials, and the potential use of associated therapy in cancer therapy.

Clinical Features and Prognostic Significance of NOTCH1 Mutations in Diffuse Large B-Cell Lymphoma

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous group of large lymphoid B cell malignancy with distinct clinical and genetic features. Recently, NOTCH1 mutations were identified in DLBCL cases by Next-generation sequencing (NGS), but the clinical features and prognostic impact were not systematically studied. Here, NOTCH1 genes in 161 DLBCL samples were sequenced by NGS. The prognostic value of NOTCH1 mutations was assessed in the context of clinical and laboratory factors, such as international prognostic index (IPI), cell-of-origin classification, double expression of BCL2 and c-MYC. The combined data from three Western cohorts were used to validate these results. As a result, NOTCH1 mutations were found in 17(10.6%) patients, and three patients had a hotspot mutation of c.7541_7542delCT. The presence of NOTCH1 mutations was significantly associated with poor complete response and progression free survival(PFS), which was independent of established clinical and laboratory parameters. In addition, 30 (1.92%) of 1562 patients treated with R-CHOP regimen in those combined Western cohorts had NOTCH1 mutations. Meta-analysis of the Western cohorts confirmed that NOTCH1 mutations were also associated with poor PFS and OS. In conclusion, DLBCL patients with the NOTCH1 mutations have worse PFS and OS, and the NOTCH1 mutations can be used as an independent predictor for patients with DLBCL.

Cytogenetic Characteristics of Childhood Acute Lymphoblastic Leukemia: A Study of 1541 Chinese Patients Newly Diagnosed between 2001 and 2014

OBJECTIVE

Cytogenetic abnormalities have been proven to be the most valuable parameter for risk stratification of childhood acute lymphoblastic leukemia (ALL). However, studies on the prevalence of cytogenetic abnormalities and their correlation to clinical features in Chinese pediatric patients are limited, especially large-scale studies.

METHODS

We collected the cytogenetics and clinical data of 1541 children newly diagnosed with ALL between 2001 and 2014 in four Chinese hospitals, and retrospectively analyzed their clinical features, prognosis and risk factors associated with pediatric ALL.

RESULTS

All of these patients had karyotyping results, and some of them were tested for fusion genes by fluorescence in situ hybridization or reverse-transcription polymerase chain reaction. Overall, 930 cases (60.4%) had abnormal cytogenetics in this study, mainly including high hyperdiploidy (HHD, n=276, 17.9%), hypodiploidy (n=74, 4.8%), t(12;21)/TEL-AML1 (n=260, 16.9%), t(1;19)/E2A-PBX1 (n=72, 4.7%), t(9;22)/BCR-ABL (n=64, 4.2%), and t(v;11q23)/MLL rearrangements (n=40, 2.6%). The distribution of each cytogenetic abnormality was correlated with gender, age, white blood cell count at diagnosis, and immunophenotype. In addition, multivariate analysis suggested that t(v;11q23)/MLL rearrangements (OR: 2.317, 95%CI: 1.219-3.748, P=0.008) and t(9;22)/BCR-ABL (OR: 2.519, 95%CI: 1.59-3.992, P<0.001) were independent risk factors for a lower event-free survival (EFS) rate in children with ALL, while HHD (OR: 0.638, 95%CI: 0.455-0.894, P=0.009) and t(12;21)/TEL-AML1 (OR: 0.486, 95%CI: 0.333-0.707, P<0.001) were independent factors of a favorable EFS.

CONCLUSION

The cytogenetic characteristics presented in our study resembled other research groups, emphasizing the important role of cytogenetic and molecular genetic classification in ALL, especially in B-ALL.

Recent Advances in Molecular Diagnosis and Prognosis of Childhood B Cell Lineage Acute Lymphoblastic Leukemia (B-ALL)

B cell lineage acute lymphoblastic leukemia is the most common leukemia occurring in children and young adults and is the leading cause of cancer related deaths. The 5 year overall survival outcome in children with B-ALL has improved significantly in the last few decades. In the past, the discovery of various genetic alterations and targeted therapy have played a major role in decreasing disease-related deaths. In addition, numerous advances in the pathogenesis of B-ALL have been found which have provided better understanding of the genes involved in disease biology with respect to diagnostic and prognostic implications. Present review will summarize current understanding of risk stratification, genetic factors including cytogenetics in diagnosis and prognosis of B-ALL.

How to Combine the Two Landmark Treatment Methods-Allogeneic Hematopoietic Stem Cell Transplantation and Chimeric Antigen Receptor T Cell Therapy Together to Cure High-Risk B Cell Acute Lymphoblastic Leukemia?

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) has made tremendous progress in the last few decades and is increasingly being used worldwide. The success of haploidentical HSCT has made it possible to have "a donor for everyone". Patients who received transplantation in remission may have a favorable outcome, while those who were transplanted in advanced stages of disease have a poor prognosis. Although chimeric antigen receptor T (CAR-T) cell therapy is currently a milestone in the immunotherapy of relapsed or refractory (R/R) B cell acute lymphoblastic leukemia (B-ALL) and has demonstrated high remission rates in patients previously treated in multiple lines, the relatively high relapse rate remains a barrier to CAR-T cell therapy becoming an excellent cure option. Therefore, combining these two approaches (allo-HSCT and CAR-T cell therapy) is an attractive area of research to further improve the prognosis of R/R B-ALL. In this review, we will discuss the current clinical practices of combining allo-HSCT with CAR-T cell therapy based on available data, including CAR-T cells as a bridge to allo-HSCT for R/R B-ALL and CAR-T cell infusion for post-transplant relapse. We will further explore not only other possible ways to combine the two approaches, including CAR-T cell therapy to clear minimal residual disease peri-transplantation and incorporation of CAR technology to treat graft-versus-host disease, but also the potential of CAR-T cells as a part of allo-HSCT.

IKZF1 Deletions as a Prognostic Factor in Costa Rican Patients With Pediatric B-Cell Acute Lymphoblastic Leukemia

The IKZF1 gene encodes for Ikaros, a transcriptional factor in B-cell development. Deletions in this gene have been associated with a worse prognosis in B-cell acute lymphoblastic leukemia (B-ALL). We evaluated the presence of these alterations in all Costa Rican pediatric patients diagnosed with B-ALL between 2011 and 2014, treated with a modified Berlin-Frankfurt-Münster therapeutic protocol. Multiplex polymerase chain reaction with 2 detection methods (agarose gel and gene scanning) was used to detect intragenic deletions and multiplex ligation-dependent probe amplification for whole-gene deletions. Differences between groups (normal vs. deleted IKZF1) were analyzed by the χ test, the Kaplan-Meier test was used to calculate relapse-free survival and overall survival, and Cox regression was performed for multivariant analysis. Minimum follow-up was 4.5 years. Incidence of IKZF1 deletions was 12.9% (n=20), with an equal amount of intragenic and complete gene deletions. Adverse karyotype (P=0.048), high-risk category (P=0.030), occurrence of relapse (P=0.021), and medullar relapse (P=0.011) were statistically associated with the presence of deletions in IKZF1. Relapse-free survival at 54 months was lower in patients harboring an IKZF1 deletion than that in patients with IKZF1-wt (40.0% vs. 66.7%; P=0.014). Patients with B-ALL and IKZF1 deletions, showed a poorer relapse-free survival, in comparison with patients with IKZF1-wt, suggesting that IKZF1 status is an independent prognostic factor for pediatric patients with B-ALL.

Treatment response, survival, safety, and predictive factors to chimeric antigen receptor T cell therapy in Chinese relapsed or refractory B cell acute lymphoblast leukemia patients

This study aimed to evaluate treatment response, survival, safety profiles, and predictive factors to chimeric antigen receptor T cell (CAR-T) therapy in Chinese patients with relapsed or refractory B cell acute lymphoblast leukemia (R/R B-ALL). 39R/R B-ALL patients who underwent CAR-T therapy were included. Baseline data were collected from patients’ electronic medical records. Patients’ peripheral bloods, bone marrow aspirates, and biopsies were obtained for routine examination, and treatment response and survival profiles as well as adverse events were evaluated. The rates of complete remission (CR), CR with minimal residual disease (MRD) negative/positive, and bridging to hematopoietic stem-cell transplantation (HSCT) were 92.3%, 76.9%, 15.4%, and 43.6%, respectively. The median event-free survival (EFS) was 11.6 months (95% confidence interval (CI): 4.0–19.2 months) and median overall survival (OS) was 14.0 months (95% CI: 10.9–17.1 months). Bridging to HSCT independently predicted better EFS and OS, while high bone marrow blasts level independently predicted worse EFS. The incidence of cytokine release syndrome (CRS) was 97.4%, and refractory disease as well as decreased white blood cell independently predicted higher risk of severe CRS. Other common adverse events included hematologic toxicities (grade I: 5.1%, grade II: 7.7%, grade III: 17.9%, grade IV: 69.2%), neurotoxicity (28.2%), infection (38.5%), and admission for intensive care unit (10.3%). In conclusion, CAR-T therapy presents with promising treatment response, survival and safety profiles, and higher disease burden predicts worse survival as well as increased risk of severe CRS in Chinese R/R B-ALL patients.

An observational study of Chinese adults with relapsed/refractory Philadelphia-negative acute lymphoblastic leukemia

Aim:

Chinese adults with relapsed/refractory Philadelphia chromosome-negative B-cell precursor acute lymphoblastic leukemia (Ph- ALL) have poor outcomes.

Patients & methods:

We conducted a nationwide, retrospective, observational study to assess outcomes in this patient population.

Results:

Of the 270 enrolled patients, 31% of patients at last salvage achieved complete remission (CR) or CR with partial hematologic recovery (CRh), with median time to CR/CRh of 30 days and median CR/CRh duration of 2.7 months. The CR/CRh rate was more favorable with earlier versus later lines of salvage (41, 24 and 17% at first, second and third or later salvages, respectively).

Conclusion:

This dataset serves as an important reference of real-world outcomes using currently available chemotherapy regimens for high-risk Chinese adults with relapsed/refractory Ph- ALL.

Treatment outcome of pediatric acute lymphoblastic leukemia in Yeungnam region: Multicenter retrospective study of Study Alliance of Yeungnam Pediatric Hematology-Oncology (SAYPH)

OBJECTIVES

We aimed to evaluate treatment outcomes of pediatric acute lymphoblastic leukemia (ALL) subgroups by risk-stratification, in the Yeungnam region of Korea.

METHODS

We reviewed the courses of 409 newly diagnosed ALL patients from January 2004 to December 2013 in the Yeungnam region.

RESULTS

All patients were classified into three risk groups: standard risk (SR, n=212), high risk (HR, n=153) and very high risk (VHR, n=44). The mean follow-up time was 73.6 ± 39.4 months. The 7-year event-free survival (EFS) and overall survival (OS) rates were 78.7 ± 2.1% and 86.8 ± 1.8%, respectively. Significant 7-year EFS and OS rates for SR (84.0 ± 2.7%, 93.7 ± 1.8%), HR (76.5 ± 3.5%, 82.1 ± 3.3%), and VHR (60.6 ± 7.5%, 69.9 ± 7.5%) were observed (P<0.001), respectively. Relapse occurred in 52 patients, and the cumulative 7-year incidence of relapse differed according to risk groups (SR vs. HR vs. VHR=12.6% vs. 14.0% vs. 29.6%, P=0.003).For the 46 relapsed patients who were treated, the 3-year EFS and OS were 42.3 ± 8.3%and 46.4± 8.4%. Among the 44 VHR patients, EFS was not significantly different between the chemotherapy-treated patients and those received hematopoietic stem cell transplantation (P=0.533). The 7-year EFS of the hyperleukocytosis subgroup (24 cases, 14 under 10 years of age)showed a tendency for better prognosis than that of the other VHR subgroups (P=0.178).

CONCLUSION

Our results revealed improved outcomes in pediatric ALL patients with risk-stratified therapy. The hyperleukocytosis subgroup without any combined chromosomal abnormalities may respond favorably to chemotherapy alone after first complete remission.

MicroRNA-9 suppresses cancer proliferation and cell cycle progression in acute lymphoblastic leukemia with inverse association of neuropilin-1

Acute lymphoblastic leukemia (ALL) is one of the most common and most malign childhood cancers. In this work, we investigated the expression and function of human mature microRNA-9 (miR-9) in ALL. In ALL in vitro cell lines and in situ clinical specimens, gene expression of miR-9 was tested by qRT-PCR. MiR-9 was overexpressed in CEM/C1 and Molt-3 cells to investigate its possible anti-cancer effects on ALL in vitro proliferation, cell-cycle progression, and in vivo explant growth. The possible downstream target of miR-9, neuropilin-1 (NRP1), was examined by dual-luciferase activity assay, qRT-PCR, and Western blot. NRP1was upregulated in miR-9-overexpressed CEM/C1 and Molt-3 cells to investigate the functional involvement of NRP1 in miR-9-mediated regulation on ALL in vitro proliferation and cell-cycle progression. MiR-9 was downregulated in ALL cell lines and leukemic T-cells of ALL patients. Lentivirus-mediated miR-9 overexpression inhibited ALL in vitro proliferation, cell-cycle progression, and in vivo explant growth. NRP1 was confirmed be the downstream target of miR-9, and inversely modulated by miR-9 in ALL. NRP1 upregulation reversed the anti-cancer regulations of miR-9 on ALL in vitro proliferation and cell-cycle progression. MiR-9 is downregulated in ALL. Overexpressing miR-9 may inhibit ALL development, possible through its downstream target of NRP1.

Targeting of heme oxygenase-1 attenuates the negative impact of Ikaros isoform 6 in adult BCR-ABL1-positive B-ALL

The correlation between Heme oxygenase-1 (HO-1) and dominant-negative Ikaros isoform 6 (IK6) is unclear. Firstly, we detected that IK6 existed in 20 of 42 (47.6%) adult BCR-ABL1-positive B-lineage acute lymphoblastic leukemia (BCR-ABL1-positive B-ALL) by using reverse transcribed polymerase chain reaction (PCR) and nucleotide sequencing. IK6-positive patients had an unfavorable outcome compared with IK6-negative ones. Further study showed that the level of HO-1 expression was higher in IK6-positive patients' samples than that in IK6-negative ones. And there was a strong correlation between the expression of IK6 and HO-1. The growth of primary CD34+ leukemic cells derived from our IK6-positive patients' pool was prohibited by silencing HO-1, further promoting their apoptosis. Furthermore, primary CD34+ leukemic cells derived from IK6-positive patients shown poor responses to imatinib in comparison with wild-type (IK1) patients, suggesting that the expression of IK6 resisted to imatinib in adult BCR-ABL1-positive B-ALL. Importantly, inhibition of HO-1 also increased their sensitivity to tyrosine kinase inhibitors (TKIs). Finally, we found that IK6 activated downstream STAT5, and HO-1 was one of the downstream target genes of STAT5. In conclusion, HO-1 is an essential survival factor in BCR-ABL1-positive B-ALL with IK6, and targeting HO-1 can attenuate the negative impact of IK6.

Loss-of-function but not dominant-negative intragenic IKZF1 deletions are associated with an adverse prognosis in adult BCR-ABL-negative acute lymphoblastic leukemia

Genetic alterations of the transcription factor IKZF1 ("IKAROS") are detected in around 15-30% of cases of BCR-ABL-negative B-cell precursor acute lymphoblastic leukemia. Different types of intragenic deletions have been observed, resulting in a functionally inactivated allele ("loss-of-function") or in "dominant-negative" isoforms. The prognostic impact of these alterations especially in adult acute lymphoblastic leukemia is not well defined. We analyzed 482 well-characterized cases of adult BCR-ABL-negative B-precursor acute lymphoblastic leukemia uniformly treated in the framework of the GMALL studies and detected IKZF1 alterations in 128 cases (27%). In 20%, the IKZF1 alteration was present in a large fraction of leukemic cells ("high deletion load") while in 7% it was detected only in small subclones ("low deletion load"). Some patients showed more than one IKZF1 alteration (8%). Patients exhibiting a loss-of-function isoform with high deletion load had a shorter overall survival (OS at 5 years 28% vs. 59%; P<0.0001), also significant in a subgroup analysis of standard risk patients according to GMALL classification (OS at 5 years 37% vs. 68%; P=0.0002). Low deletion load or dominant-negative IKZF1 alterations had no prognostic impact. The results thus suggest that there is a clear distinction between loss-of-function and dominant-negative IKZF1 deletions. Affected patients should thus be monitored for minimal residual disease carefully to detect incipient relapses at an early stage and they are potential candidates for alternative or intensified treatment regimes. (clinicaltrials.gov identifiers: 00199056 and 00198991).

Efficacy and prognostic factors of imatinib plus CALLG2008 protocol in adult patients with newly diagnosed Philadelphia chromosome-positive acute lymphoblastic leukemia

A CALLG2008 protocol was developed by the Chinese Acute Lymphoblastic Leukemia Cooperative Group for adult acute lymphoblastic leukemia (ALL). We retrospectively analyzed 153 newly diagnosed adult patients with Philadelphia chromosome (Ph)-positive ALL enrolled into imatinib (400 mg/d) plus CALLG2008 regimen between 2009 and 2015. The median age was 40 years (range, 18-68 years), with 81 (52.3%) males. The overall hematologic complete remission (CR) rate was 96.7% after induction. With a median follow-up of 24.2 months, the estimated 3-year overall survival (OS) and event-free survival (EFS) rates were 49.5%(95%confidence interval (CI): 38.5%-59.5%) and 49.2% (95% CI: 38.3%-59.2%), respectively. Fifty-eight (36 with haploidentical donor) patients underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) in first CR. Among the patients in CR1 after induction, both the 3-year OS and EFS were significantly better in the allo-HSCT group than in the without allo-HSCT group (73.2%, 95% CI: 58.3%-83.5% vs. 22.2%, 95% CI: 8.7%-39.6% and 66.5%, 95% CI: 50.7%-78.2% vs. 16.1%, 95% CI: 5.1%-32.7%, respectively). Multivariate analysis showed that allo-HSCT and achievement of major molecular response were associated with favorable OS or EFS independently. Interestingly, in the allo-HSCT cohort, the donor type (haploidentical versus matched donors) had no significant impact on EFS or OS. All these results suggested that imatinib plus CALLG2008 was an effective protocol for Ph-positive ALL. Haploidentical donors can also be a reasonable alternative expedient donor pool.

Genomic Profiling of Adult and Pediatric B-cell Acute Lymphoblastic Leukemia

Genomic landscapes of 92 adult and 111 pediatric patients with B-cell acute lymphoblastic leukemia (B-ALL) were investigated using next-generation sequencing and copy number alteration analysis. Recurrent gene mutations and fusions were tested in an additional 87 adult and 93 pediatric patients. Among the 29 newly identified in-frame gene fusions, those involving MEF2D and ZNF384 were clinically relevant and were demonstrated to perturb B-cell differentiation, with EP300-ZNF384 inducing leukemia in mice. Eight gene expression subgroups associated with characteristic genetic abnormalities were identified, including leukemia with MEF2D and ZNF384 fusions in two distinct clusters. In subgroup G4 which was characterized by ERG deletion, DUX4-IGH fusion was detected in most cases. This comprehensive dataset allowed us to compare the features of molecular pathogenesis between adult and pediatric B-ALL and to identify signatures possibly related to the inferior outcome of adults to that of children. We found that, besides the known discrepancies in frequencies of prognostic markers, adult patients had more cooperative mutations and greater enrichment for alterations of epigenetic modifiers and genes linked to B-cell development, suggesting difference in the target cells of transformation between adult and pediatric patients and may explain in part the disparity in their responses to treatment.

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The genomic landscapes of adult and pediatric B-ALL were defined by next-generation sequencing of patient samples.

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MEF2D and ZNF384 fusions could perturb B-cell differentiation or induce leukemia in mice and exhibited clinical relevance.

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Adult patients showed greater enrichment for alterations of genes linked to epigenetic modification and B-cell development.

This study comprehensively addressed the genomic signatures of adult versus pediatric B-ALL. The identification of distinct MEF2D and ZNF384 fusions expands the existing knowledge about molecular subtypes of B-ALL in both age groups. RNA-seq data allowed most of the B-ALL cases to be clustered into 8 subgroups related to genetic abnormalities. Notably, adult patients have more cooperative sequence variation mutations than pediatric patients, especially in genes involved in epigenetic regulation and B-cell development. These findings may improve our understanding of leukemogenesis in B-ALL, leading to a more precise genetic classification and the further development of targeted therapy in this disease.

IKZF1 alterations and expression of CRLF2 predict prognosis in adult Chinese patients with B-cell precursor acute lymphoblastic leukemia

Acute Lymphoblastic Leukemia (ALL) is a common hematological malignancy in children, with a prognosis much worse in adults. The molecular characterization of ALL and its correlated prognostic significance are largely unknown. In this study, we analyzed the frequency of IKZF1 deletions, IK6 isoform, and CRLF2 overexpression in 118 Chinese adult B-cell precursor ALL (B-ALL) patients to explore their associations with clinical prognosis. Our data showed that IKZF1 deletions and IK6 isoform were highly detected in adult patients, and both of them were related with worse prognosis in Ph^- B-ALL, HR group of Ph^- B-ALL, and/or B-ALL patients. Though the frequency of CRLF2 overexpression was similar to children, it had an independent prognostic significance for standard-risk and Ph^- adult patients. Our study provided insights into the prognostic significance of certain genetic features in B-ALL patients. Further therapeutic strategies targeting these abnormalities potentially improving the prognosis of B-ALL are warranted.

A six gene expression signature defines aggressive subtypes and predicts outcome in childhood and adult acute lymphoblastic leukemia

Abnormal gene expression in cancer represents an under-explored source of cancer markers and therapeutic targets. In order to identify gene expression signatures associated with survival in acute lymphoblastic leukemia (ALL), a strategy was designed to search for aberrant gene activity, which consists of applying several filters to transcriptomic datasets from two pediatric ALL studies. Six genes whose expression in leukemic blasts was associated with prognosis were identified:three genes predicting poor prognosis (AK022211, FASTKD1 and STARD4) and three genes associated with a favorable outcome (CAMSAP1, PCGF6 and SH3RF3). Combining the expression of these 6 genes could successfully predict prognosis not only in the two discovery pediatric ALL studies, but also in two independent validation cohorts of adult patients, one from a publicly available study and one consisting of 62 newly recruited Chinese patients. Moreover, our data demonstrate that our six gene based test is particularly efficient in stratifying MLL or BCR.ABL negative patients. Finally, common biological traits characterizing aggressive forms of ALL in both children and adults were found, including features of dormant hematopoietic stem cells, suggesting new therapeutic strategies.

Fighting against hematological malignancy in China: from unique system to global impact

During recent decades, substantial progress has been made in clinical strategies for treating hematological malignancies. Not only did China benefit from the global progression in the management of acute promyelocytic leukemia, risk-stratification-directed strategies for acute or chronic leukemia and haploidentical hematopoietic stem cell transplantation, the unique system developed by Chinese doctors has also become inspiration for refining global clinical practice. The multicenter trials and collaborations adhering to international standards might further strengthen the global impact and lead the way in specific fields of research worldwide.

Effects of plant-derived anti-leukemic drugs on individualized leukemic cell population profiles in Egyptian patients

Leukemias are a group of cancer types that originate from blood-forming tissues. In this disease, an abnormally large number of immature white blood cells is produced by the bone marrow. The relationship between treatments with plant-derived drugs and leukemia-associated immunophenotypes (LAIPs) of clinically isolated leukemia cells has yet to be established. The aim of the present study was to develop a preliminary clinical prognostic map for commonly expressed LAIPs in patients clinically diagnosed with leukemia, as well as to assess the potential involvement of LAIPs in the response rate to 10 natural products of plant origin. An increased expression of LAIPs, including CD4, CD14, CD33 and CD34, was considered a surrogate marker of the desired response of leukemia cells to treatment with plant-derived drugs. By contrast, the increased expression of the LAIPs, MPO and DR, was associated with poor prognostic outcomes following treatment with the plant-derived drugs. The results showed that 5 of the 10 plant-derived drugs tested induced the expression of several desirable LAIPs biomarkers. These findings clearly highlight the potential treatment efficacy of certain plant-derived drugs against leukemic cell types.

Prognostic value of rare IKZF1 deletion in childhood B-cell precursor acute lymphoblastic leukemia: an international collaborative study

Deletions in IKZF1 are found in ~15% of children with B-cell precursor acute lymphoblastic leukemia (BCP-ALL). There is strong evidence for the poor prognosis of IKZF1 deletions affecting exons 4-7 and exons 1-8, but evidence for the remaining 33% of cases harboring other variants of IKZF1 deletions is lacking. In an international multicenter study we analyzed the prognostic value of these rare variants in a case-control design. Each IKZF1-deleted case was matched to three IKZF1 wild-type controls based on cytogenetic subtype, treatment protocol, risk stratification arm, white blood cell count and age. Hazard ratios for the prognostic impact of rare IKZF1 deletions on event-free survival were calculated by matched pair Cox regression. Matched pair analysis for all 134 cases with rare IKZF1 deletions together revealed a poor prognosis (P<0.001) that was evident in each risk stratification arm. Rare variant types with the most unfavorable event-free survival were DEL 2-7 (P=0.03), DEL 2-8 (P=0.002) and DEL-Other (P<0.001). The prognosis of each type of rare variant was equal or worse compared with the well-known major DEL 4-7 and DEL 1-8 IKZF1 deletion variants. We therefore conclude that all variants of rare IKZF1 deletions are associated with an unfavorable prognosis in pediatric BCP-ALL.

Clinical characteristics of acute lymphoblastic leukemia in male and female patients: A retrospective analysis of 705 patients

The aim of the present study was to compare the clinical characteristics of acute lymphoblastic leukemia (ALL) that occurred in male and female patients at one institution in Southern China. The medical electronic records of Nanfang Hospital, affiliated to Southern Medical University, were searched for patients with a definite diagnosis of ALL that were diagnosed between January 1, 2001 and December 31, 2012. The clinical data of the patients were collected and analyzed. A total of 705 eligible patients were identified. The gender ratio of male to female patients was 1.84:1. The average ages at the time of diagnosis were 16.43 and 19.54 years for male and female patients, respectively (P=0.007). No significant differences were identified in the seasonal occurrence distribution, blood group distribution or ratio for the presence of the Ph chromosome between males and females. However, a higher incidence of T-cell type ALL was identified in males (P=0.023). The present study reveals that ALL demonstrates a male predominance, but similar clinical characteristics of ALL are present in males and females in Southern China.

Prognostic significance of cytokine receptor-like factor 2 alterations in acute lymphoblastic leukemia: a meta-analysis

BACKGROUND

Cytokine receptor-like factor 2 (CRLF2) has been shown to play a role in the pathogenesis of acute lymphoblastic leukemia (ALL). Studies have examined the relationship between CRLF2 alterations such as over-expression or deregulation and clinical outcome in childhood ALL, but the results are conflicting. This meta-analysis aimed to explore the association between CRLF2 alterations and survival of pediatric patients with ALL.

METHODS

Electronic databases updated to March 2014 were searched for relevant studies. A meta-analysis was made of twelve studies including 5945 patients to evaluate the prognostic significance of CRLF2 alterations on survival in childhood ALL. Hazards ratios (HRs) with 95% confidence intervals (CIs) were pooled across the studies using a fixed-effects model.

RESULTS

CRLF2 over-expression in childhood ALL was associated with poor prognosis in terms of relapse-free survival (RFS; HR=1.70, 95% CI=1.28-2.24, P=0.000), event-free survival (EFS; HR=1.78, 95% CI=1.05-3.01, P=0.032), and overall survival (OS; HR=2.28, 95% CI=1.42-3.65, P=0.001). The combined data also suggested that CRLF2 deregulation in childhood ALL was correlated with poor EFS (HR=1.95, 95% CI=1.46-2.61, P=0.000), RFS (HR=2.20, 95% CI=1.53-3.18, P=0.000), and OS (HR=1.89, 95% CI=1.24-2.87, P=0.003). Subgroup analysis on multivariate HRs showed that CRLF2 deregulation independently predicted a poor prognosis for childhood ALL.

CONCLUSIONS

The present meta-analysis reveals that both CRLF2 over-expression and deregulation are associated with poor prognosis in pediatric patients with ALL.

Leukemia propagating cells rebuild an evolving niche in response to therapy

Residence of cancer-propagating cells (CPCs) within preferential microenvironmental niches has a major part in evading therapy. However, the nature of niches involved and the mechanisms protecting CPCs remain largely unknown. We addressed these issues in mouse transplantation models of acute lymphoblastic leukemia (ALL). When the engrafted leukemic cells substantially damaged adjacent microenvironment in the bone marrow (BM), after chemotherapy small foci of CPCs were retained, surrounded by sheaths of supporting cells that comprise a protective niche. We investigated patients' BM biopsies and found evidence of a similar process in patients receiving induction therapy. The efficacy of chemotherapy was enhanced by interfering with the niche formation or function. We therefore identified a therapy-induced niche that protects CPCs.

Excellent outcomes for adolescents and adults with acute lymphoblastic leukemia and lymphoma without allogeneic stem cell transplant: the FRALLE-93 pediatric protocol

Adolescents and adults with acute lymphoblastic leukemia/lymphoma (ALL) have better outcomes when treated using pediatric protocols compared with treatment using adult protocols. We reviewed the progress and outcomes of 40 adolescents and adults up to 45 years of age, from three Australian centers, treated on the intensive French group for childhood ALL (FRALLE)-93 pediatric protocol. All except one patient achieved a morphologic complete remission following induction chemotherapy. Three-year overall survival for all-risk and standard-risk disease was 70% and 75%, respectively. The treatment protocol was generally well tolerated with no treatment related mortality. The FRALLE-93 pediatric protocol showed excellent overall survival for patients with standard-risk disease, without the need for allogeneic hematopoietic stem cell transplant in first remission.

Ik6 expression provides a new strategy for the therapy of acute lymphoblastic leukemia

Our previous study demonstrated that the dominant-negative Ikaros isoform 6 (Ik6) is overexpressed in Chinese children with newly diagnosed B-acute lymphoblastic leukemia (B-ALL) and is strongly associated with a poor outcome. The purpose of the present study was to further explore the function of Ik6 in B-ALL. The association between Ik6 expression as detected by real-time PCR and efficacy of chemotherapy was evaluated. The effect of the alteration in Ik6 on leukemic cell lines was assessed by in vitro gain-of-function and loss-of-function techniques. PCR analysis showed that Ik6 expression was decreased when patients completed induction chemotherapy and reached complete remission. Ik6 expression was significantly increased when patients suffered relapse. Stable transfection of Ik6 into the Nalm-6 cell line revealed that Ik6 enhanced proliferation of Nalm-6 cells through the promotion of G0/G1-to-S-phase transition and enhanced chemoresistance to chemotherapeutics through anti-apoptotic effects. However, Ik6 expression did not affect the invasion of Nalm-6 cells. In contrast, silencing of Ik6 in Sup-B15 cells significantly inhibited proliferation and increased chemosensitivity. The present study suggests that Ik6 may be a biological marker of chemosensitivity and relapse and Ik6 may provide a potential therapeutic strategy for ALL.

Management of adult and paediatric acute lymphoblastic leukaemia in Asia: resource-stratified guidelines from the Asian Oncology Summit 2013

Survival for adults and children with acute lymphoblastic leukaemia has risen substantially in recent years because use of improved risk-directed treatments and supportive care has widened. In nearly all developed countries, multidisciplinary panels of leukaemia experts have formulated clinical practice guidelines in which standard treatment approaches are recommended on the basis of current evidence. However, those guidelines do not take into account resource limitations in low-income countries, including financial and technical challenges. In Asia, huge disparities in economy and infrastructure exist between countries, and even among different regions in some large countries. At a consensus session held as part of the 2013 Asian Oncology Summit in Bangkok, Thailand, a panel of experts summarised recommendations for management of adult and paediatric acute lymphoblastic leukaemia. Strategies were developed for Asian countries on the basis of available financial, skill, and logistical resources and were stratified in a four-tier system according to the resources available in a particular country or region (basic, limited, enhanced, and maximum).

IKZF1 and CRLF2 gene alterations correlate with poor prognosis in Japanese BCR-ABL1-negative high-risk B-cell precursor acute lymphoblastic leukemia

BACKGROUND

Genome-wide analysis studies have demonstrated that IKZF1, CRLF2, and JAK2 gene alterations correlate with poor prognosis in pediatric B-cell precursor acute lymphoblastic leukemia (BCP-ALL). However, the prognostic significance for these gene alterations has not been clarified in Japanese patients.

PROCEDURE

A total of 194 patients with BCP-ALL enrolled in the Japanese Children's Cancer & Leukemia Study Group ALL 2004 clinical trial were assessed for the presence of three different gene alterations: IKZF1 deletions, CRLF2 expression and JAK2 mutation.

RESULTS

IKZF1 deletions and CRLF2-high expression were identified in 22 of 177 (12%) patients and in 15 of 141 (11%) patients, respectively. However, JAK2 R683 mutation was detected only one of 177 patients. The 4-year event-free survival (4y-EFS) was different when comparing patients with or without IKZF1 deletions (68.2% vs. 85.2%; P = 0.04) and was also different when comparing patients with different CRLF2 expression levels (high, 66.7% vs. low, 88.1%; P = 0.03). The differences in 4y-EFS were statistically significant in patients with ALL in the National Cancer Institute (NCI)-high risk group (HR-ALL) (IKZF1 deletions: yes, 58.3% vs. no, 87.0%, P = 0.02; CRLF2 expression: high, 55.6% vs. low, 85.3%, P = 0.04) but not in patients with ALL in the NCI-standard risk group (SR-ALL; IKZF1 deletions: yes, 80.0% vs. no, 84.4%, P = 0.75; CRLF2 expression: high, 83.3% vs. low, 89.2%, P = 0.77). Coexistence of IKZF1 deletions and CRLF2-high expression associated with poor outcomes.

CONCLUSIONS

IKZF1 deletions and CRLF2-high expression predicted poor outcomes in patients with HR-ALL but not in patients with SR-ALL in our Japanese cohort.

An intragenic ERG deletion is a marker of an oncogenic subtype of B-cell precursor acute lymphoblastic leukemia with a favorable outcome despite frequent IKZF1 deletions

Oncogenic subtypes in childhood B-cell precursor acute lymphoblastic leukemia (BCP-ALL) are used for risk stratification. However, a significant number of BCP-ALL patients are still genetically unassigned. Using array-comparative genomic hybridization in a selected BCP-ALL cohort, we characterized a recurrent V(D)J-mediated intragenic deletion of the ERG gene (ERG(del)). A breakpoint-specific PCR assay was designed and used to screen an independent non-selected cohort of 897 children aged 1-17 years treated for BCP-ALL in the EORTC-CLG 58951 trial. ERG(del) was found in 29/897 patients (3.2%) and was mutually exclusive of known classifying genetic lesions, suggesting that it characterized a distinct leukemia entity. ERG(del) was associated with higher age (median 7.0 vs. 4.0 years, P=0.004), aberrant CD2 expression (43.5% vs. 3.7%, P<0.001) and frequent IKZF1 Δ4-7 deletions (37.9% vs. 5.3%, P<0.001). However, ERG(del) patients had a very good outcome, with an 8-year event-free survival (8-y EFS) and an 8-year overall survival of 86.4% and 95.6%, respectively, suggesting that the IKZF1 deletion had no impact on prognosis in this genetic subtype. Accordingly, within patients with an IKZF1 Δ4-7 deletion, those with ERG(del) had a better outcome (8-y EFS: 85.7% vs. 51.3%; hazard ratio: 0.16; 95% confidence interval: 0.02-1.20; P=0.04). These findings have implications for further stratification including IKZF1 status.

Complementary regulation of early B-lymphoid differentiation by genetic and epigenetic mechanisms

Although B lymphopoiesis is one of the best-defined paradigms in cell differentiation, our knowledge of the regulatory mechanisms underlying its earliest processes, in which hematopoietic stem cells (HSCs) enter the B lineage, is limited. However, recent methodological advances in sorting progenitor cells and monitoring their epigenetic features have increased our understanding of HSC activities. It is now known that even the highly enriched HSC fraction is heterogeneous in terms of lymphopoietic potential. While surface markers and reporter proteins provide information on the sequential differentiation of B-lineage progenitors, complex interactions between transcription factors have also been shown to play a major role in this process. Epigenetic regulation of histones, nucleosomes, and chromatin appears to play a crucial background role in this elaborate transcription network. In this review, we summarize recent findings on the physiological processes of early B-lineage differentiation, which provides a new paradigm for understanding the harmonious action of genetic and epigenetic mechanisms.

Prognostic significance of monitoring leukemia-associated immunophenotypes by eight-color flow cytometry in adult B-acute lymphoblastic leukemia

Minimal residual disease (MRD) is of the most important factor for predicting prognosis and guiding treatment of acute lymphoblastic leukemia (ALL). In this study, we investigated the prognostic significance of leukemia-associated immunophenotypes (LAIPs) as assessment of index of MRD in 125 adult B-lineage ALL (B-ALL) patients by eight-color flow cytometry. The LAIPs could be identified in 96% and 81.6% of patients with the sensitivity of 10(-4) and 10(-5), respectively. MRD-negative status could clearly predict a favorable 2-year relapse-free survival (RFS) and overall survival (OS) at the end of induction of complete remission and one cycle of consolidation treatment. Moreover, we identified a group of cases with MRD of 0.001% to <0.01%, which showed significantly higher 2-year relapse rate than those with undetectable one. In multivariate analysis, MRD status was associated with RFS or OS independently. Furthermore, MRD assessed by LAIPs and RQ-PCR assay for patients with BCR-ABL fusion gene yielded concordant results in 89.7% of cases. In conclusion, MRD evaluated by eight-color flow cytometry could provide an important tool to assess treatment response and prognosis precisely in adult B-ALL.

Has MRD monitoring superseded other prognostic factors in adult ALL?

Significant improvements have been made in the treatment of acute lymphoblastic leukemia (ALL) during the past 2 decades, and measurement of submicroscopic (minimal) levels of residual disease (MRD) is increasingly used to monitor treatment efficacy. For a better comparability of MRD data, there are ongoing efforts to standardize MRD quantification using real-time quantitative PCR of clonal immunoglobulin and T-cell receptor gene rearrangements, real-time quantitative-based detection of fusion gene transcripts or breakpoints, and multiparameter flow cytometric immunophenotyping. Several studies have demonstrated that MRD assessment in childhood and adult ALL significantly correlates with clinical outcome. MRD detection is particularly useful for evaluation of treatment response, but also for early assessment of an impending relapse. Therefore, MRD has gained a prominent position in many ALL treatment studies as a tool for tailoring therapy with growing evidence that MRD supersedes most conventional stratification criteria at least for Ph-negative ALL. Most study protocols on adult ALL follow a 2-step approach with a first classic pretherapeutic and a second MRD-based risk stratification. Here we discuss whether and how MRD is ready to be used as main decisive marker and whether pretherapeutic factors and MRD are really competing or complementary tools to individualize treatment.