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Patients with chronic myelomonocytic leukemia (CMML) have monocytosis and likely a state of chronic inflammation. Both have been associated with an increased risk of atherosclerosis. The aim of the study was to test the hypothesis that CMML patients are at increased risk of developing cardiovascular disease (CVD) due to persistent monocytosis and sustained chronic inflammation. In a retrospective cohort study, we assessed hazards for cardiovascular events after diagnosis in 112 CMML patients and 231 chronic lymphocytic leukemia (CLL) patients. Analyses were carried out on restricted cohorts (CMML = 84, CLL = 186), excluding patients with a prior history of CVD, as well as on unrestricted cohorts. In the restricted cohorts, a significant effect of cardiovascular event occurrence did not remain after adjustment (HR 2.49, 95% CI 0.94-6.60). In unrestricted cohorts, we found a more than twofold increased rate of cardiovascular events in CMML (HR 2.34, 95% CI 1.05-5.20). Our results indicate an increased risk of CVD after the diagnosis in CMML patients.

Due to the high efficacy of BCR-ABL tyrosine kinase inhibition (TKI) in chronic phase (CP) chronic myeloid leukemia (CML), the frequency of blast crisis (BC) is greatly reduced compared to the pre-TKI era. However, TKI treatment of BC has only marginally improved the number of favorable responses, including remissions, which for the most part have only been transitory. Occasionally, they provide a therapeutic window to perform an allogeneic stem cell transplantation (allo-SCT). The challenge remains to improve management of BC with the limited options available. We review and summarize articles pertaining to the treatment of BC CML published after 2002. Additionally, we will discuss whether there is a need for a new definition of BC and/or treatment failure.

Allogeneic hematopoietic stem cell transplantation (HSCT) is currently recommended as 2nd or 3rd line therapy for patients with chronic myeloid leukemia (CML) in first chronic phase or as salvage for patients with very advanced disease. As a consequence, numbers of HSCT in chronic phase have dropped significantly since the introduction of tyrosine kinase inhibitors (TKI), numbers of transplants in advanced disease to a lesser extent. These current recommendations consider primarily disease risk, defined as failure of TKI therapy; they might need to be adapted. We propose a more balanced appraisal of HSCT for individual patients which should include disease risk, transplant risk, and macroeconomic aspects. HSCT should be integrated into the treatment algorithms from diagnosis and be considered very early at first TKI failure for patients with high disease but low transplant risk. For patients with very advanced disease and high transplant risk in contrast, HSCT might only be recommended in a restricted research setting.

Several guidelines and recommendations on the management of chronic myeloid leukemia (CML) have been prepared by several scientific societies. The European LeukemiaNet (ELN) appointed a panel of experts who submitted their recommendations to peer-reviewed scientific journals in 2006, 2009, and 2013. Here, we make a critical review of the last, 2013, ELN recommendations, concerning the use of the five available tyrosine kinase inhibitors (TKIs), the evaluation of cytogenetic and molecular response, and the strategy of treatment. Three TKIs (imatinib, nilotinib, dasatinib) are recommended first-line. Bosutinib and ponatinib are available second-line; ponatinib is particularly indicated in case of the T315I mutation. Achieving an optimal response, not only for survival but also for a deeper, stable, treatment-free remission, requires a BCR-ABL transcripts level ≤ 10 % at 3 months, ≤ 1 % at 6 months, ≤ 0.1 % at 1 year, and ≤ 0.01 % later on. Molecular monitoring must include mutational analysis in every case of failure. A successful treatment of accelerated and blastic phase requires TKIs, and in many cases also allogeneic stem cell transplantation.

Chronic myeloid leukaemia (CML) is a myeloproliferative disorder arising in the haemopoietic stem cell (HSC) compartment. This disease is characterised by a reciprocal t(9;22) chromosomal translocation, resulting in the formation of the Philadelphia (Ph) chromosome containing the BCR-ABL1 gene. As such, diagnosis and monitoring of disease involves detection of BCR-ABL1. It is the BCR-ABL1 protein, in particular its constitutively active tyrosine kinase activity, that forges the pathogenesis of CML. This aberrant kinase signalling activates downstream targets that reprogram the cell to cause uncontrolled proliferation and results in myeloid hyperplasia and 'indolent' symptoms of chronic phase (CP) CML. Without successful intervention, the disease will progress into blast crisis (BC), resembling an acute leukaemia. This advanced disease stage takes on an aggressive phenotype and is almost always fatal. The cell biology of CML is also centred on BCR-ABL1. The presence of BCR-ABL1 can explain virtually all the cellular features of the leukaemia (enhanced cell growth, inhibition of apoptosis, altered cell adhesion, growth factor independence, impaired genomic surveillance and differentiation). This article provides an overview of the clinical and cell biology of CML, and highlights key findings and unanswered questions essential for understanding this disease.

Imatinib has represented a revolution in the treatment of chronic myeloid leukemia (CML), inducing an overall survival never seen with previous therapies. However, with the commonly used dosage of 400 mg, one third of the treated patients does not reach the criteria associated with an optimal outcome and could potentially benefit from a different treatment strategy. Several trials exploring modified imatinib-based treatments or second-generation tyrosine-kinase as front-line therapy have been performed. In some studies, high-dose (800 mg per day) or dose-adapted imatinib or imatinib plus interferon was reported to be able to induce better cytogenetic and molecular responses compared with standard-dose imatinib, although no improvements in progression-free survival (PFS) or overall survival (OS) have been so far reported. At the moment, these approaches are still considered investigational. On the other side, on the basis of their capacity to induce very fast and deep molecular responses, including major molecular responses (MMRs) and the newly defined very deep molecular responses MR⁴ and MR(4.5), and to prevent at least part of the early progressions to AP/BC that still occur during the first 2-3 years from diagnosis, dasatinib and nilotinib have been approved and registered by FDA and EMA as the first-line therapy for CML patients, opening the possibility to use different therapeutic strategies for newly diagnosed CML patients and a consequent intense debate among hematologists.

Sphingolipids are bioeffector molecules that control various aspects of cell growth, proliferation, apoptosis, and drug resistance. Ceramides, the central molecule of sphingolipid metabolism, are inducer of apoptosis and inhibitors of proliferation. Sphingosine-1-phosphate (S1P) and glucosyleceramide, converted from ceramides by sphingosine kinase-1 (SK-1) and glucosyleceramide synthase (GCS) enzymes, respectively, inhibit apoptosis and develop resistance to chemotherapeutic drugs. In this study, we examined the therapeutic potentials of bioactive sphingolipids in chronic myeloid leukemia (CML) alone and in combination with dasatinib in addition to investigate the roles of ceramide-metabolizing genes in dasatinib-induced apoptosis. Cytotoxic effects of dasatinib, C8:ceramide, PDMP, and SK-1 inhibitor were determined by XTT cell proliferation assay. Changes in caspase-3 enzyme activity and mitochondrial membrane potential (MMP) were measured using caspase-3 colorimetric assay and JC-1 MMP detection kit. Expression levels of ceramide-metabolizing genes were examined by qRT-PCR. Application of ceramide analogs and inhibitors of ceramide clearance genes decreased cell proliferation and induced apoptosis. Targeting bioactive sphingolipids towards generation/accumulation of ceramides increased apoptotic effects of dasatinib, synergistically. It was shown for the first time that dasatinib induces apoptosis through downregulating expression levels of antiapoptotic SK-1 but not GCS, and upregulating expression levels of ceramide synthase (CerS) genes, especially CerS1, in K562 cells. On the other hand, dasatinib downregulates expression levels of both GCS and SK-1 and upregulate apoptotic CerS2, -5 and -6 genes in Meg-01 cells. Increasing endogenous ceramide levels and decreasing prosurvival lipids, S1P, and GC, can open the way of more effective treatment of CML.

We measured intracellular accumulation of N-desmethyl imatinib (CGP 74588), the main pharmacologically active metabolite of imatinib (Gleevec or STI-571), in Bcr--Abl-positive cells. Using a sensitive and robust non-radioactive in vitro assay, we observed that CGP74588 accumulates in significantly higher amount than imatinib in sensitive K562 cells. In contrast, the intracellular level of CGP74588 was significantly lower than that of imatinib in K562/Dox cells, which represent a multidrug-resistant variant of K562 cells due to the P-glycoprotein (P-gp, ABCB1, MDR1) overexpression. An in vitro enzyme-based assay provided evidence that CGP74588 might serve as an excellent substrate for P-gp. Accordingly, we found that CGP74588 up to 20 μM concentration neither induced apoptosis nor inhibited substantially cell proliferation in resistant K562/Dox cells. In contrast, CGP74588 was capable to inhibit cell proliferation and induced apoptosis in sensitive K562 cells, although its effect was approximately three to four times lower than that of imatinib in the same cell line. Our results indicate that CGP74588 could hardly positively contribute to the treatment of chronic myeloid leukemia (CML) where ABCB1 gene overexpression represents a possible mechanism of resistance to imatinib in vivo.

Assay of phosphotyrosine levels using flow cytometry has been used to identify patients with chronic myelogenous leukemia positive for the Bcr-Abl fusion gene. We hypothesized that clinical monitoring could identify treatment response through reductions in intragranulocyte phosphotyrosine. Initially, we studied cell lines FDC-P1 and HL60 (Bcr-Abl-negative) and FDrv210 and K562 (Bcr-Abl-positive) with our technique. A fluorescein isothiocyanate-conjugated monoclonal antibody was used along with fluorescence-conjugated microspheres for reference (ratio of sample fluorescence: bead fluorescence = relative fluorescence unit [RFU]). Samples from 20 controls and 32 patients undergoing treatment were analyzed using the same method. Bcr-Abl status for each patient was confirmed using fluorescent in situ hybridization or polymerase chain reaction gene amplification (PCR). Testing of cell lines consistently produced expected results. Patient values were found to be significantly higher than control values (P < 0.001) and values for patients with advanced disease were significantly higher than for patients with chronic-phase disease (P < 0.05). Results of clinical monitoring were consistent with results from PCR. Two patients who received allogeneic stem cell transplantation had molecular remission confirmed by PCR and had a marked decrease in RFU value (from 62 to five and from 131 to 23). No such fluorescence change was observed in patients who achieved clinical remission. Flow cytometric analysis of phosphotyrosine levels is a reliable and convenient adjuvant technique for diagnosis of Bcr-Abl-positive leukemias and shows promise for serial evaluation of patients undergoing treatment.

In a prospective multicenter phase-II trial 80 patients with Philadelphia (Ph)-positive chronic myelogenous leukemia (CML) were treated with recombinant interferon (IFN) alpha-2c, administered subcutaneously at an absolute dose of 3.5 megaunits (MU)/day. Complete hematological remission was achieved in 29 (39%) and partial hematological remission in 26 (35%) of the 74 patients evaluable for response. Major cytogenetic responses were observed in ten (13%) and minor cytogenetic responses in 11 patients (15%). Median duration of cytogenetic response was 33 months (range, 2-90); relapses were seen in all of the 11 patients with minor and in three of the ten patients with major cytogenetic responses. Median survival estimates for pretreated (n = 19) and untreated (n = 58) patients were 51 months (95% confidence interval [CI], 30-72) and 77 months (95% CI, 43-111), and the survival probabilities at 5 years were 45% and 54% for the two groups, respectively. Hematological response after 3 months of treatment demonstrated a clear-cut discriminative capacity with 5-year survival probabilities of 100%, 67% and 24% for patients achieving CHR (n = 6), PHR (n = 34), and less than PHR (n = 35), respectively. Landmark analysis at 12, 18, and 24 months after start of IFN therapy and an analysis treating time to cytogenetic response as a time-dependent covariate showed that cytogenetic response was associated with longer survival. The impact of a low-dose IFN regimen on survival in CML patients is unclear and requires further clarification by randomized clinical trials. Early hematological and cytogenetic response to IFN-alpha treatment identifies patients with a favorable long-term prognosis.

We report the clinical, hematologic, cytogenetic, and molecular characteristics of 13 patients with Philadelphia-negative (Ph-), bcr-negative atypical chronic myelogenous leukemia (CML). In the majority of cases, the phenotypic features at presentation resembled those of typical CML. However, these patients presented with a higher median age, lower median hemoglobin levels, and lower leukocyte and platelet counts than patients with Ph-positive CML. Cytogenetic analysis showed an abnormal karyotype in only one case. Southern blot investigation, using probes exploring the entire M-bcr region, demonstrated the absence of genomic bcr-abl rearrangements. The assessment of clonality in five patients (study of X-methylation patterns in females heterozygous at the DXS255 locus) indicated the proliferation of a monoclonal cell population. Disease evolution was mostly characterized by bone marrow failure, extramedullary infiltrates, and poor response to chemotherapy, without evidence of overt acute transformation. Our observations suggest that some hematologic and clinical features and the modalities of disease progression are presently the most helpful factors in distinguishing these bcr/abl-negative patients from those with typical bcr+CML. The differences existing also with chronic myelomonocytic leukemia (CMMoL), allow the consideration of ph-/bcr- CML as a separate entity, the nature of which remains to be elucidated.