Molecular remission at the end of treatment is a necessary goal for a good outcome in ELN favorable-risk acute myeloid leukemia: a real-life analysis on 201 patients by the Rete Ematologica Lombarda network.

Favorable acute myeloid leukemia (AML) patients (pts.) demonstrate a relatively good outcome with standard induction; thus, pts. are generally not addressed to allogeneic transplant in first remission. However, it is not clear if also in a real-life setting, the outcome is homogeneous in the different favorable molecular groups and which are the parameters significantly associated to an increased relapse risk, useful to suggest the need of an intensified approach. In order to clarify this point, we collected clinical data on consecutive unselected AML pts. assigned to favorable category (modified ELN 2010 due to the inclusion of double-mutated CEBPA-positive cases), diagnosed and treated in six centers of the Italian network Rete Ematologica Lombarda (REL) from 2007 to 2015. We assessed response (CR, mCR), relapse rate (CIR), and outcome (OS, DFS) after first-line treatment. A total of 201 pts. was studied and the analysis was performed globally and in each molecular group: t(8;21)(q22;q22)/RUNX1-RUNX1T1 (30 pts., 14.9%), inv. (16)(p13q22) or t(16;16)(p13q22)/CBFB-MIH11 (35 pts., 17.4%), normal karyotype and mutated NPM1 and negative FLT3-ITD (116 pts., 57.7%) or double-mutated CEBPA (CEBPAdm) (20 pts., 10%). Complete remission (CR) was obtained in 188 pts. (93.5%), molecular CR (mCR) in 114 (67.5%); After a median follow-up of 2.4 years, cumulative incidence of relapse (CIR) was documented in 78 of 188 responding pts. (41%) after a median time of 11.3 months. CIR was higher in the CBFB-MIH11 group, in pts. achieving only a hematological response without mCR (72.1 vs 28.1%, p < 0.001), in older pts. and it resulted independently associated with a lower median cytarabine cumulative dose (CCD). Median OS was not reached: after 5 years it was 66.3%, and median DFS was 5.3 years, both without difference among groups. Molecular CR reached at any time, during or after the end of first-line treatment, was significantly associated with better DFS, and in particular, mCR assessed at the end of treatment was confirmed in multivariate analysis as an independent prognostic factor both for DFS and OS. In conclusion, the present study confirms in a real-life context the overall good prognosis of favorable-risk AML; the achievement of any molecular negativity during first-line treatment, particularly when assessed at the end of treatment, is associated with lower relapse and better survival. Increasing age at diagnosis has a negative prognostic impact, while CCD higher than 18 g/sqm is associated with better outcome.

Therapeutically targeting SELF-reinforcing leukemic niches in acute myeloid leukemia: A worthy endeavor?

A tight relationship between the acute myeloid leukemia (AML) population and the bone marrow (BM) microenvironment has been convincingly established. The AML clone contains leukemic stem cells (LSCs) that compete with normal hematopoietic stem cells (HSCs) for niche occupancy and remodel the niche; whereas, the BM microenvironment might promote AML development and progression not only through hypoxia and homing/adhesion molecules, but also through genetic defects. Although it is still unknown whether the niche influences treatment results or contains any potential target for treatment, this dynamic AML-niche interaction might be a promising therapeutic objective to significantly improve the AML cure rate.

Does cytogenetic evolution have any prognostic relevance in myelodysplastic syndromes? A study on 153 patients from a single institution.

The present study was designed to establish the incidence of cytogenetic evolution (CE), defined as the acquisition of chromosomal defects during the course of MDS, in order to correlate it with the WHO classification and IPSS score, and to assess its impact on overall survival (OS) and risk of MDS/AML evolution (progression-free interval, PFI) by means of Cox models for time-dependent covariates. Adjustments for known risk factors were achieved by performing a bivariable analysis. The study was carried out in 153 MDS patients who were followed for a median period of 45.2 months. Disease progression occurred in 42.4% of patients after a 65.2-month median PFI, while CE occurred in 30.7% of patients. Our study shows that (1) CE was more common in advanced than in early MDS, and advanced MDS presented secondary chromosomal defects distinct from those of early MDS; (2) CE significantly affected OS and PFI independently of other prognostic variables; (3) del(7)(q31q34) was the only secondary chromosomal defect which significantly affected PFI; trisomy 8 had only a moderate influence.

Alternative splicing of hTERT: a further mechanism for the control of active hTERT in acute myeloid leukemia.

hTERT component is the key regulator of telomerase. Alternatively spliced variants of hTERT generate different telomerase activity. The goal of the study was to determine the role of different hTERT isoforms in the regulation of telomerase expression in AML patients. Among the 97 studied patients, 45 had a complex karyotype and 52 a normal karyotype. hTERT isoforms expression was determined in bone marrow samples by q-RT-PCR, using SYBR Green I. hTERT expression was lower in AML patients than controls (median 2.5 vs. 10.1, p = .003), though no difference was observed between the complex and normal karyotype (median 3.2 vs. 2.3, p = .37). High trans-dominant negative isoform expression increased the response rate by two. High expression of inactive product (-α - ß) was shown to increase the risk of relapse by about three times. In conclusion, our data suggest an intriguing link between the control of hTERT isoforms expression and AML outcome.

'Real-life' study of imatinib therapy in chronic phase-chronic myeloid leukemia: A novel retrospective observational longitudinal analysis.

OBJECTIVES: Imatinib is a cornerstone of treatment of chronic myeloid leukemia. It remains unclear whether transient treatment discontinuation or dose changes affect outcome and this approach has not yet been approved for use outside clinical trials. METHODS: We conducted a retrospective single-institution observational study to evaluate factors affecting response in 'real-life' clinical practice in 138 chronic myeloid leukemia patients in chronic phase treated with imatinib. We used a novel longitudinal data analytical model, with a generalized estimating equation model, to study BCR-ABL variation according to continuous standard dose, change in dose or discontinuation; BCR-ABL transcript levels were recorded. Treatment history was subdivided into time periods for which treatment was given at constant dosage (total 483 time periods). Molecular and cytogenetic complete response was observed after 154 (32%) and 358 (74%) time periods, respectively. RESULTS: After adjusting for length of time period, no association between dose and cytogenetic complete response rate was observed. There was a significantly lower molecular complete response rate after time periods at a high imatinib dosage. DISCUSSION: This statistical approach can identify individual patient variation in longitudinal data collected over time and suggests that changes in dose or discontinuation of therapy could be considered in patients with appropriate biological characteristics.

MDS/AML del(11)(q14) Share Common Morphological Features Despite Different Chromosomal Breakpoints.

In myelodysplatic syndromes and acute myeloid leukemia (MDS/AML) deletion of the 11q14 region is a rare chromosomal defect (incidence: 0.6-1.0%), included within the intermediate risk criteria by the International Prognostic Scoring System. No fluorescence in situ hybridization (FISH) study has yet been performed to identify a common breakpoint region (CBR). In our study through FISH with bacterial artificial chromosomes and commercial probes, we analyzed seven patients with MDS/AML harboring 11q14 deletion on conventional cytogenetic analysis. FISH revealed deletions in five patients and amplifications in two. Three patients with deletion carried a CBR, two had a deletion involving a more centromeric breakpoint. These five patients exhibited multilineage dysplasia, blast cells with large round nuclei, loose chromatin, small and abundant nucleoli, and vacuolated cytoplasm with very thin Auer bodies. In conclusion, the morphological features which occur independently of the extent of the deletion are of multilineage dysplasia in MDS and leukemic blasts strongly reactive to peroxidase in AML; despite the variable size of the deleted area, some patients harbor a CBR.

Detection of TET2 abnormalities by fluorescence in situ hybridization in 41 patients with myelodysplastic syndrome.

TET2 haplo-insufficiency occurs through different molecular mechanisms and is promptly revealed by array comparative genomic hybridization, single nucleotide polymorphism (SNP) array, and next-generation sequencing (NGS). Fluorescence in situ hybridization (FISH) can effectively demonstrate TET2 deletions and is often used to validate molecular results. In the present study 41 MDS patients with and without 4q abnormalities were analyzed with a series of bacterial artificial chromosome (BAC) probes spanning the 4q22.3-q25 region. On conventional cytogenetic (CC) studies, a structural defect of the long arm of chromosome 4 (4q) was observed in seven patients. In three, one each with a t(1;4)(p21;q24), an ins(5;4)(q23;q24qter), and a t(4;17)(q31;p13) as the sole chromosomal abnormality, FISH with the RP11-356L5 and RP11-16G16 probes, which cover the TET2 locus, produced one signal only. Unexpectedly, this same result was achieved in 3 of the remaining 34 patients. Thus, a TET2 deletion was observed in a total of six patients (14.6%). TET2 deletion was not correlated with any particular clinical findings or outcome. These findings demonstrate that 1) FISH is an effective and economical method to reveal cryptic abnormalities of band 4q22-q24 resulting in TET2 deletions; 2) in these patients, TET2 deletion is the unifying genetic event; and 3) the different breakpoints within the 4q22-q25 region suggest that deletions are not mediated by repetitive sequences.