Eva Hellström-Lindberg

The 2008 revision of the World Health Organization (WHO) classification of myeloid neoplasms and acute leukemia: rationale and important changes

Recently the World Health Organization (WHO), in collaboration with the European Association for Haematopathology and the Society for Hematopathology, published a revised and updated edition of the WHO Classification of Tumors of the Hematopoietic and Lymphoid Tissues. The 4th edition of the WHO classification incorporates new information that has emerged from scientific and clinical studies in the interval since the publication of the 3rd edition in 2001, and includes new criteria for the recognition of some previously described neoplasms as well as clarification and refinement of the defining criteria for others. It also adds entities-some defined principally by genetic features-that have only recently been characterized. In this paper, the classification of myeloid neoplasms and acute leukemia is highlighted with the aim of familiarizing hematologists, clinical scientists, and hematopathologists not only with the major changes in the classification but also with the rationale for those changes.

Efficacy of azacitidine compared with that of conventional care regimens in the treatment of higher-risk myelodysplastic syndromes: a randomised, open-label, phase III study

BACKGROUND Drug treatments for patients with high-risk myelodysplastic syndromes provide no survival advantage. In this trial, we aimed to assess the effect of azacitidine on overall survival compared with the three commonest conventional care regimens. METHODS In a phase III, international, multicentre, controlled, parallel-group, open-label trial, patients with higher-risk myelodysplastic syndromes were randomly assigned one-to-one to receive azacitidine (75 mg/m(2) per day for 7 days every 28 days) or conventional care (best supportive care, low-dose cytarabine, or intensive chemotherapy as selected by investigators before randomisation). Patients were stratified by French-American-British and international prognostic scoring system classifications; randomisation was done with a block size of four. The primary endpoint was overall survival. Efficacy analyses were by intention to treat for all patients assigned to receive treatment. This study is registered with ClinicalTrials.gov, number NCT00071799. FINDINGS Between Feb 13, 2004, and Aug 7, 2006, 358 patients were randomly assigned to receive azacitidine (n=179) or conventional care regimens (n=179). Four patients in the azacitidine and 14 in the conventional care groups received no study drugs but were included in the intention-to-treat efficacy analysis. After a median follow-up of 21.1 months (IQR 15.1-26.9), median overall survival was 24.5 months (9.9-not reached) for the azacitidine group versus 15.0 months (5.6-24.1) for the conventional care group (hazard ratio 0.58; 95% CI 0.43-0.77; stratified log-rank p=0.0001). At last follow-up, 82 patients in the azacitidine group had died compared with 113 in the conventional care group. At 2 years, on the basis of Kaplan-Meier estimates, 50.8% (95% CI 42.1-58.8) of patients in the azacitidine group were alive compared with 26.2% (18.7-34.3) in the conventional care group (p<0.0001). Peripheral cytopenias were the most common grade 3-4 adverse events for all treatments. INTERPRETATION Treatment with azacitidine increases overall survival in patients with higher-risk myelodysplastic syndromes relative to conventional care.

Somatic SF3B1 mutation in myelodysplasia with ring sideroblasts.

BACKGROUND Myelodysplastic syndromes are a diverse and common group of chronic hematologic cancers. The identification of new genetic lesions could facilitate new diagnostic and therapeutic strategies. METHODS We used massively parallel sequencing technology to identify somatically acquired point mutations across all protein-coding exons in the genome in 9 patients with low-grade myelodysplasia. Targeted resequencing of the gene encoding RNA splicing factor 3B, subunit 1 (SF3B1), was also performed in a cohort of 2087 patients with myeloid or other cancers. RESULTS We identified 64 point mutations in the 9 patients. Recurrent somatically acquired mutations were identified in SF3B1. Follow-up revealed SF3B1 mutations in 72 of 354 patients (20%) with myelodysplastic syndromes, with particularly high frequency among patients whose disease was characterized by ring sideroblasts (53 of 82 [65%]). The gene was also mutated in 1 to 5% of patients with a variety of other tumor types. The observed mutations were less deleterious than was expected on the basis of chance, suggesting that the mutated protein retains structural integrity with altered function. SF3B1 mutations were associated with down-regulation of key gene networks, including core mitochondrial pathways. Clinically, patients with SF3B1 mutations had fewer cytopenias and longer event-free survival than patients without SF3B1 mutations. CONCLUSIONS Mutations in SF3B1 implicate abnormalities of messenger RNA splicing in the pathogenesis of myelodysplastic syndromes. (Funded by the Wellcome Trust and others.).

Azacitidine Prolongs Overall Survival Compared With Conventional Care Regimens in Elderly Patients With Low Bone Marrow Blast Count Acute Myeloid Leukemia

PURPOSE In a phase III randomized trial, azacitidine significantly prolonged overall survival (OS) compared with conventional care regimens (CCRs) in patients with intermediate-2- and high-risk myelodysplastic syndromes. Approximately one third of these patients were classified as having acute myeloid leukemia (AML) under current WHO criteria. This analysis compared the effects of azacitidine versus CCR on OS in this subgroup. PATIENTS AND METHODS Patients were randomly assigned to receive subcutaneous azacitidine 75 mg/m(2)/d or CCR (best supportive care [BSC] only, low-dose cytarabine (LDAC), or intensive chemotherapy [IC]). RESULTS Of the 113 elderly patients (median age, 70 years) randomly assigned to receive azacitidine (n = 55) or CCR (n = 58; 47% BSC, 34% LDAC, 19% IC), 86% were considered unfit for IC. At a median follow-up of 20.1 months, median OS for azacitidine-treated patients was 24.5 months compared with 16.0 months for CCR-treated patients (hazard ratio = 0.47; 95% CI, 0.28 to 0.79; P = .005), and 2-year OS rates were 50% and 16%, respectively (P = .001). Two-year OS rates were higher with azacitidine versus CCR in patients considered unfit for IC (P = .0003). Azacitidine was associated with fewer total days in hospital (P < .0001) than CCR. CONCLUSION In older adult patients with low marrow blast count (20% to 30%) WHO-defined AML, azacitidine significantly prolongs OS and significantly improves several patient morbidity measures compared with CCR.

A validated decision model for treating the anaemia of myelodysplastic syndromes with erythropoietin + granulocyte colony-stimulating factor: significant effects on quality of life

Summary. We have published previously a prototype of a decision model for anaemic patients with myelodysplastic syndromes (MDS), in which transfusion need and serum erythropoietin (S‐Epo) were used to define three groups with different probabilities of erythroid response to treatment with granulocyte colony‐stimulating factor (G‐CSF) + Epo. S‐Epo ≤ 500 U/l and a transfusion need of < 2 units/month predicted a high probability of response to treatment, S‐Epo > 500 U/l and ≥ 2 units/month for a poor response, whereas the presence of only one negative prognostic marker predicted an intermediate response. A total of 53 patients from a prospective study were included in our evaluation sample. Patients with good or intermediate probability of response were treated with G‐CSF + Epo. The overall response rate was 42% with 28·3% achieving a complete and 13·2% a partial response to treatment. The response rates were 61% and 14% in the good and intermediate predictive groups respectively. The model retained a significant predictive value in the evaluation sample (P < 0·001). Median duration of response was 23 months. Scores for global health and quality of life (QOL) were significantly lower in MDS patients than in a reference population, and fatigue and dyspnoea was significantly more prominent. Global QOL improved in patients responding to treatment (P = 0·01). The validated decision model defined a subgroup of patients with a response rate of 61% (95% confidence interval 48–74%) to treatment with G‐CSF + Epo. The majority of these patients have shown complete and durable responses.

Efficacy of erythropoietin in the myelodysplastic syndromes: a meta-analysis of 205 patients from 17 studies.

Erythropoietin (epo) can be used to improve the anaemia of patients with myelodysplastic syndromes (MDS), but the efficacy is relatively low and the treatment is expensive. So far, no individual clinical trial has been sufficiently extensive to provide a basis for a decision model for the use of epo in MDS. This meta-analysis included 17 original articles with a total of 205 patients with MDS who had been treated with epo. 33 patients (16%) showed a significant response to treatment. Patients with refractory anaemia with ring sideroblasts (RAS) showed a lower response rate than all other patients (7.5% v 21%, P = 0.010). The difference in response rate between patients with and without transfusion need was also highly significant (10% v 44%, P < 0.001). The serum level of epo was significantly lower in the responding patients, but this parameter on its own could not be used to identify patients with a favourable response. FAB group (RAS versus others), transfusion need and s-epo (>/< 200 U/l) were combined in a model to provide information about the probability of response in different groups of patients. Patients with no transfusion requirement and MDS other than RAS showed a response rate of > or = 50%, irrespective of their serum level of epo. In patients with RAS and s-epo > 200 U/l, no response was observed. In the remaining groups the response rates varied between 9% and 33%. This meta-analysis shows that the efficacy of epo in MDS in general was low, but that groups of patients with an acceptable response rate could be identified.

A randomized phase 3 study of lenalidomide versus placebo in RBC transfusion-dependent patients with Low-/Intermediate-1-risk myelodysplastic syndromes with del5q

This phase 3, randomized, double-blind study assessed the efficacy and safety of lenalidomide in 205 red blood cell (RBC) transfusion-dependent patients with International Prognostic Scoring System Low-/Intermediate-1-risk del5q31 myelodysplastic syndromes. Patients received lenalidomide 10 mg/day on days 1-21 (n = 69) or 5 mg/day on days 1-28 (n = 69) of 28-day cycles; or placebo (n = 67). Crossover to lenalidomide or higher dose was allowed after 16 weeks. More patients in the lenalidomide 10- and 5-mg groups achieved RBC-transfusion independence (TI) for ≥ 26 weeks (primary endpoint) versus placebo (56.1% and 42.6% vs 5.9%; both P < .001). Median duration of RBC-TI was not reached (median follow-up, 1.55 years), with 60% to 67% of responses ongoing in patients without progression to acute myeloid leukemia (AML). Cytogenetic response rates were 50.0% (10 mg) versus 25.0% (5 mg; P = .066). For the lenalidomide groups combined, 3-year overall survival and AML risk were 56.5% and 25.1%, respectively. RBC-TI for ≥ 8 weeks was associated with 47% and 42% reductions in the relative risks of death and AML progression or death, respectively (P = .021 and .048). The safety profile was consistent with previous reports. Lenalidomide is beneficial and has an acceptable safety profile in transfusion-dependent patients with Low-/Intermediate-1-risk del5q myelodysplastic syndrome. This trial was registered at www.clinicaltrials.gov as #NCT00179621.

Diagnosis and treatment of primary myelodysplastic syndromes in adults: recommendations from the European LeukemiaNet

Within the myelodysplastic syndrome (MDS) work package of the European LeukemiaNet, an Expert Panel was selected according to the framework elements of the National Institutes of Health Consensus Development Program. A systematic review of the literature was performed that included indexed original papers, indexed reviews and educational papers, and abstracts of conference proceedings. Guidelines were developed on the basis of a list of patient- and therapy-oriented questions, and recommendations were formulated and ranked according to the supporting level of evidence. MDSs should be classified according to the 2008 World Health Organization criteria. An accurate risk assessment requires the evaluation of not only disease-related factors but also of those related to extrahematologic comorbidity. The assessment of individual risk enables the identification of fit patients with a poor prognosis who are candidates for up-front intensive treatments, primarily allogeneic stem cell transplantation. A high proportion of MDS patients are not eligible for potentially curative treatment because of advanced age and/or clinically relevant comorbidities and poor performance status. In these patients, the therapeutic intervention is aimed at preventing cytopenia-related morbidity and preserving quality of life. A number of new agents are being developed for which the available evidence is not sufficient to recommend routine use. The inclusion of patients into prospective clinical trials is strongly recommended.

Clinical significance of SF3B1 mutations in myelodysplastic syndromes and myelodysplastic/myeloproliferative neoplasms

In a previous study, we identified somatic mutations of SF3B1, a gene encoding a core component of RNA splicing machinery, in patients with myelodysplastic syndrome (MDS). Here, we define the clinical significance of these mutations in MDS and myelodysplastic/myeloproliferative neoplasms (MDS/MPN). The coding exons of SF3B1 were screened using massively parallel pyrosequencing in patients with MDS, MDS/MPN, or acute myeloid leukemia (AML) evolving from MDS. Somatic mutations of SF3B1 were found in 150 of 533 (28.1%) patients with MDS, 16 of 83 (19.3%) with MDS/MPN, and 2 of 38 (5.3%) with AML. There was a significant association of SF3B1 mutations with the presence of ring sideroblasts (P < .001) and of mutant allele burden with their proportion (P = .002). The mutant gene had a positive predictive value for ring sideroblasts of 97.7% (95% confidence interval, 93.5%-99.5%). In multivariate analysis including established risk factors, SF3B1 mutations were found to be independently associated with better overall survival (hazard ratio = 0.15, P = .025) and lower risk of evolution into AML (hazard ratio = 0.33, P = .049). The close association between SF3B1 mutations and disease phenotype with ring sideroblasts across MDS and MDS/MPN is consistent with a causal relationship. Furthermore, SF3B1 mutations are independent predictors of favorable clinical outcome, and their incorporation into stratification systems might improve risk assessment in MDS.

TP53 Mutations in Low-Risk Myelodysplastic Syndromes With del(5q) Predict Disease Progression

PURPOSE To determine the frequency of TP53 mutations and the level of p53 protein expression by immunohistochemistry (IHC) in low-risk myelodysplastic syndromes (MDS) with del(5q) and to assess their impact on disease progression. PATIENTS AND METHODS Pre- and postprogression bone marrow (BM) samples from 55 consecutive patients with International Prognostic Scoring System low risk (n = 32) or intermediate-1 risk (n = 23) were studied by next-generation sequencing of TP53. IHC for p53 was performed on 148 sequential BM samples. RESULTS TP53 mutations with a median clone size of 11% (range, 1% to 54%) were detected in 10 patients (18%) already at an early phase of the disease. Mutations were equally common in low-risk and intermediate-1-risk patients and were associated with evolution to acute myeloid leukemia (5 of 10 v 7 of 45; P = .045). Nine of 10 patients carrying mutations showed more than 2% BM progenitors with strong p53 staining. The probability of a complete cytogenetic response to lenalidomide was lower in mutated patients (0 of 7 v 12 of 24; P = .024). CONCLUSION By using sensitive deep-sequencing technology, we demonstrated that TP53 mutated populations may occur at an early disease stage in almost a fifth of low-risk MDS patients with del(5q). Importantly, mutations were present years before disease progression and were associated with an increased risk of leukemic evolution. TP53 mutations could not be predicted by common clinical features but were associated with p53 overexpression. Our findings indicate a previously unrecognized heterogeneity of the disease which may significantly affect clinical decision making.