Torsten Haferlach

..Here, we present a robust approach for a systematic and quantitative comparison of published gene expression signatures with an exemplary query dataset...

..An ongoing international study (MILE study) is testing the accuracy, sensibility and specificity of gene expression profiling in leukemia diagnostics. First results and future directions will be given in the article...

..This method may therefore guide therapeutic decisions and should be investigated in a diagnostic setting in parallel to established standard methods...

..Due to the rapid expansion of known molecular markers, this paper aims to outline some of the recent progress to improve understanding of the pathogenesis in these myeloid malignancies...

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..The Microarray Innovations in Leukemia study assessed the clinical utility of gene expression profiling as a single test to subtype leukemias into conventional categories of myeloid and lymphoid malignancies...

..In conclusion, AML with t(8;16) demonstrates unique cytomorphological, cytogenetic, molecular and prognostic features and is a specific subtype of AML...

..A stringent diagnostic algorithm for characterization, choice of treatment, and monitoring of MRD will be proposed in this review...

..The results serve as a mandatory prerequisite for individual treatment strategies and for the evaluation of treatment response using especially newly defined and highly specific MRD markers...

..INTERPRETATION AND CONCLUSIONS: FLT3 expression levels are correlated with clinical data, genetic subgroups as well as prognosis. Furthermore, our data indicate that FLT3 expression and signaling are closely associated with FAB M5...

..The proposed scoring systems for OS and TTT based on a combination of genetic markers improve the separation of prognostic subgroups in CLL already early in the course of the disease...

..Mean WBC count was highest in NPM1-mut/FLT3-ITD-positive and lowest in NPM1-wildtype/FLT3-ITD-negative patients (p<0.0001); similar for BM blasts. Therefore, FLT3-ITD and NPM1mut might synergistically stimulate blast proliferation...

..Similar results were obtained in patients undergoing second-line chemotherapy or allogeneic stem cell transplantation...

..The 1225 patients with de novo AML were separated according to age as follows: A1: 16 to 49 years (n=442), A2: 50 to 59 years (n=246), A3: 60-69 years (n=333), A4: 70 years and older (n=204)...

..In the future, diagnostic procedures may include oligonucleotide microarray analysis (MA) to detect expression patterns of large numbers of specific genes...

..6%) and associated with a significant lower overall survival (P = 0.0339). In addition, cases with bcr3 showed a tendency for a worse event-free survival (P = 0.0795) compared with the bcr1 group...

..MFC-based quantification of MRD reveals important prognostic information in unselected patients with AML in addition to cytogenetics and should be further evaluated and used in clinical trials...

..4%, 56.4%, 34.0%, 12.6%; mEFS: n.r., 18.1 months, 8.7 months, 2.5 months). The impact on outcome of this score was independent of NPM1mut/FLT3-ITD- status, MLL-PTD, and age...

..To refine cytogenetically based risk-stratification in acute myeloid leukemia (AML)...

..We also assessed the clinical significance of the recently introduced World Health Organization (WHO) classification for AML, which proposed dysplasia as a new parameter for classification...

..These data support a possible future application of microarray technology for classification of the acute leukemias...

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..Therefore, some KD mutations (e.g., T315I) might be associated with higher genetic instability paving the way to additional cytogenetic and molecular genetic events...

..In conclusion, next-generation amplicon sequencing enables the highly sensitive detection of molecular mutations and is a feasible assay for routine assessment of GC-rich content amplicons...

..Our data (1) confirm that inv(3)/t(3;3) AML has a poor prognosis (2) show that age and initial WBC are risk factors for prognosis; (3) suggest that this group may benefit from allogeneic stem cell transplantation...

..Thus, MLD alone showed no independent clinical effect, whereas cytogenetics and MDS history were prognostically relevant...

..The present analysis aimed at improving the applicability of this approach to more patients with AML...

..Our study confirms the variety of ETV6 rearrangements in AML, MDS, and MPNs often in association with other genetic events. Prognosis of ETV6 rearranged de novo AML seems to be intermediate, which should be independently confirmed...

..Finally, BCOR mutations tended to be associated with an inferior outcome in a cohort of 422 CN-AML patients (25.6% vs 56.7% overall survival at 2 years; P = .032). Our results for the first time implicate BCOR in CN-AML pathogenesis...

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..These data may be the basis for developing targeted therapeutic strategies to increase the cure rate in patients with AML and a complex aberrant karyotype...

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..We improved the identification of this parameter by implementing multiparameter flow cytometry to quantify bone marrow cells carrying leukemia-associated immunophenotypes (LAIP)...

..These data emphasize a close relationship between MBL and CLL regarding clinically relevant parameters and provide no evidence to strictly separate these entities by a distinct threshold of clonal B-cells...

..In conclusion, FLT3-mutations are extremely heterogenous with mutation load being the most relevant parameter...

..The detection of minimal residual disease (MRD) for predicting prognosis and for therapeutic planning still are under discussion...

..The results of the present study indicate that in the absence of FLT3 mutations, FLT3 overexpression might be a mechanism for FLT3 activation, which cooperates with RUNX1 mutations in leukemogenesis...

..Alterations of the short arm of chromosome 12 (12p) occur in various hematologic malignancies and ETV6 and CDKN1B, which are located on 12p, have been implicated as leukemogenic genes of interest...

..Multivariate analysis showed independent prognostic relevance for overall survival for RUNX1mut (P = .029), FLT3-ITD (P = .003), age (P < .001), and white blood cell count (P < .002)...

..08 log (range, 1.22-4.01) and 2.28 log (range, 1.12-3.34) with and without CD45 gating. CD45 gating improves the sensitivity of MFC-based MRD monitoring in AML by 1 log...

..In conclusion, t(8;21), +11, +13, and +14 are strongly associated with AML M0, M1, and M2. The FISH screening analyses identified abnormalities in an additional 3% in normal karyotypes...

..By combining the transcription ratios at these 2 checkpoints, a new powerful prognostic score has been established...

..80·1 months, P = 0·015). In conclusion, the del(14q) is a rare recurrent alteration in diverse mature B-cell neoplasms, shows variable size but distinct clustering of breakpoints, and is associated with short time to treatment...

..The introduction of all trans retinoic acid (ATRA) into treatment protocols has improved the outcome of APL dramatically. Therefore, it is essential to establish the diagnosis of APL as quickly and as reliably as possible...

..Thus far, data on a comprehensive cytogenetic or molecular genetic characterization are limited...

..9%); and (5) very unfavorable: TP53 mutation (n = 80; OS at 3 years: 0%; P < .001). This comprehensive molecular characterization provides a more powerful model for prognostication than cytogenetics...

..It is suggested to be expressed more weakly in patients with myelodysplastic syndromes (MDS). The analysis of MNDA therefore may improve diagnostic capabilities of multiparameter flow cytometry (MFC) in MDS...

..043). In conclusion, RUNX1 mutations are an important novel biomarker for a comprehensive characterization of T-cell acute lymphoblastic leukemia with poor prognostic impact and have implications for use also in monitoring disease...

..However, there was a trend to better survival in most subgroups, especially when other molecular markers (FLT3-LM, MLL-PTD, and NPM) were taken into account...

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..In conclusion, the combined MDS-EVI1/EVI1 gene may serve as an alternative MRD marker in AML, especially in samples where other specific markers are lacking...

..In conclusion, this study demonstrates that NPM1+/FLT3-LM- mutations are an independent predictor for a favorable outcome in AML with normal karyotype...

..Accordingly, cluster analysis completely separated all 13 subgroups analyzed. Gene expression profiling can predict all clinically relevant subentities of leukemia with high accuracy...

..Deleted sites on 13q14 appeared to be located within the breakpoint regions of the translocations. We show that mechanisms other than interstitial deletions may lead to loss of critical chromosomal regions in CLL...

..In most patients with acute myeloid leukemia, multiparameter flow cytometry may be used to monitor minimal residual disease...

..Furthermore, it is anticipated that new biologically defined and clinically relevant subtypes of leukemia will be identified based on gene expression profiling. This method may therefore guide therapeutic decisions...

..Gene expression profiling should also lead to the detection of new biological and clinically relevant subtypes in leukemia and therefore guide therapeutic decisions...

..However, detailed data on the population-based age-dependent incidences of distinct cytogenetic subtypes as well as of molecular mutations are lacking...

..Therefore, trisomy 8 in AML determines no specific disease characteristic but is a disease modulating secondary event...

..001). In addition, 21 of 234 CML (9.0%) and 7 of 155 ALL (4.5%) cases carried the FLT3 D324N. Our data suggest that the FLT3 D324N variant might be associated with a predisposition to different subtypes of leukemia...

..A FIP1L1-PDGFRA fusion gene was identified in four male patients by interphase FISH and RT-PCR. These methods in combination demonstrated clonality in 8/40 patients (20%) with a male predominance (6/8; 75%)...

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..0001), may partly contribute to the different phenotypes. However, linear regression analysis demonstrated that genes differentially expressed between M3 and M3v did not correlate with FLT3-LM...

..In cases in which a myeloproliferative neoplasm cannot be established, analysis for TET2, CBL and EZH2 mutations may be indicated...

..001). In conclusion, we confirmed BRAFmut as a useful marker in HCL, its absence in HCL variant, and developed an RT-PCR-based assay to monitor minimal residual disease in HCL...

..This could also lead to the identification of new targets for future drugs...

..039) especially in the age group < 60 years (P = .028). In conclusion, these data show that IDH1R132 may significantly add information regarding characterization and prognostication in AML...

..In conclusion, the central role of morphology as defined by the FAB and WHO classification in AML at diagnosis is still justified in combination with other techniques...

..Patients with KIT-D816-positive/AML1-ETO-positive AML might benefit from early intensification of treatment or combination of conventional chemotherapy with KIT PTK inhibitors...

..Thus, it is desirable to establish new molecular markers for PCR-based studies. Large clinical trials will determine the role and place of immunologic and PCR-based monitoring in the prognostic stratification of patients with AML...

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..Furthermore, gene expression profiling may also lead to the detection of new biologically defined and clinically relevant subtypes in leukemia and guide therapeutic decision-making in the future...

..0 vs 8.9 months, P =.36). In conclusion, the category AML with 11q23/MLL abnormalities accounts for 2.8% of unselected AML, is closely associated with monocytic differentiation, and has a dismal prognosis. (..

..Compared to translocations involving MLL and other partner genes, complex rearrangements are unique for MLL-AF10 fusions. This may result from the opposite orientation of MLL and AF10...

..Our results show for the first time that in addition to known mutations in the JM and the catalytic domain, further activating length mutations exist in the FLT3 gene...

..The prognostic impact of this unbalanced aberration and of gains of 9p in chronic myeloproliferative disorders remains to be clarified...

..Thus, diagnostics in the CMPD transform toward a multimodal diagnostic concept based on a combination of methods - cyto-/histomorphology, cytogenetics, and individual molecular methods which can be included in a diagnostic algorithm...

..0001), LDH (P <.0001), and day 16 blasts (P =.0359). The prognostic significance of day 16 blasts is independent of pretherapeutic parameters and predicts outcome even in patients achieving a CR...

..The diagnosis and classification of myelodysplastic syndromes (MDS) is based on cytomorphology (CM) and cytogenetics (CG). Multiparameter flow cytometry (MFC) may add important diagnostic information...

..We demonstrate that FISH analysis underestimates the complexity of chromosomal aberrations in CLL. Therefore, conventional cytogenetics may define subgroups of patients with high risk of progression...

..Thus, increasing WT1 levels in molecular responders may indicate Ph-negative clonal cytogenetic evolution during imatinib treatment...

..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...

..Gene expression profiling has the potential to offer consistent, objective diagnostic test results once a standardized protocol has been established. We investigated the robustness, precision, and reproducibility of microarray technology...

..By using two different strategies for microarray data analyses, this study revealed a unique correlation between AML-specific cytogenetic aberrations and gene expression profiles...

..262; p=0.012). Median age of onset was lower than in the V617Fmut controls (58.5 vs. 67.8 years, p<0.001). In conclusion, JAK2 exon 12 mutation analysis contributes to diagnostics in polycythemia vera or erythrocytosis...

..ZAP-70 provides an important prognostic information in chronic lymphocytic leukemia (CLL); however, the most appropriate antibody clone and way of analysis have not yet been defined...

..In ET and in HES the aberration rate was only 3 and 7%, respectively. Thus, cytogenetics can be omitted. However, in some of these cases molecular procedures should be integrated into the routine diagnostic process...

..In contrast, we found an additional favorable impact of FLT3-TKD on EFS in prognostically favorable AML with NPM1- or CEBPA mutations...

..They are also consistent with the existence and subsequent transformation of progenitor populations with lymphoid/myeloid potential...

..Moreover, targeting of G1 regulatory proteins and the resulting induction of G1 arrest by A3D8 may provide new insights into antiproliferative and differentiation therapy of AML...

..Taken together, these findings make NPMc+ acute myeloid leukemia a good candidate for inclusion in the upcoming World Health Organization classification...

..This new technique should be further validated in parallel to the standard work-flow and has to be proven before substituting other methods in the future...

..6 months; P =.0072) because of a higher relapse rate. Besides the importance of FLT3-LM for biologic and clinical characterization of AML, we show its value as a marker for disease monitoring based on 120 follow-up samples of 34 patients...

..In conclusion, we showed that unique gene expression patterns can be correlated with FLT3-ITD and FLT3-TKD. This might lead to the identification of further pathogenetic relevant candidate genes particularly in AML with normal karyotype...

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..The incidence of submicroscopic deletions was 2-9% depending on the entity...

..We performed allelotyping and p53 mutation analysis in 75 patients with morphologically and cytogenetically classified AML...

..The increased expression of p21/WAF/Cip1 in primary leukemic blasts suggests that elevated p21/WAF/Cip1 levels may contribute to specific features observed in AML1-ETO positive leukemia...