Adult acute lymphoblastic leukemia: concepts and strategies

Frequency of chromosomal abnormalities in Pakistani adults with acute lymphoblastic leukemia

BACKGROUND

The difference in prognosis of adult and childhood acute lymphoblastic leukemia (ALL) can be attributed largely to variation in cytogenetic abnormalities with age groups. Cytogenetic analysis in acute leukemia is now routinely used to assist patient management, particularly in terms of diagnosis, disease monitoring, prognosis and risk stratification. Knowing about cytogenetic profile at the time of diagnosis is important in order to take critical decisions in management of the patients.

AIM AND OBJECTIVES

To determine the frequency of cytogenetic abnormalities in Pakistani adult patients with ALL in order to have insights regarding behavior of the disease.

MATERIALS AND METHODS

A retrospective analysis of all the cases of ALL (≥15years old) diagnosed at Aga Khan University from January 2006 to June 2014 was performed. Phenotype (B/T lineage) was confirmed in all cases by flow cytometry. Cytogenetic analysis was made for all cases using the trypsin-Giemsa banding technique. Karyotypes were interpreted using the International System for Human Cytogenetic Nomenclature (ISCN) criteria.

RESULTS

A total of 166 patients were diagnosed as ALL during the study period, of which 151 samples successfully yielded metaphase chromosomes. The male to female ratio was 3.4:1. The majority (n=120, 72.3%) had a B-cell phenotype. A normal karyotype was present in 51% (n=77) of the cases whereas 49% (n=74) had an abnormal karyotype. Of the abnormal cases, 10% showed Philadelphia chromosome; t(9;22)(q34;q11.2). Other poor prognostic cytogenetic subgroups were t(4;11)(q21;q23), hypodiploidy (35-45 chromosomes) and complex karyotype. Hyperdiploidy (47-57 chromosomes) occurred in 6.6%; all of whom were younger than 30 years.

CONCLUSIONS

This study showed a relatively low prevalence of Philadelphia chromosome in Pakistani adults with ALL with an increase in frequency with age (p=0.003). The cumulative prevalence of Philadelphia- negative poor cytogenetic aberrations in different age groups was not significant (p=0.6).

Serum peptidome based biomarkers searching for monitoring minimal residual disease in adult acute lymphocytic leukemia

BACKGROUND

The persistence of minimal residual disease (MRD) during therapy is the strongest adverse prognostic factor in acute lymphocytic leukemia (ALL). This study was to identify serum candidate peptides for monitoring MRD in adult ALL.

RESULTS

A total of 33 peptides in the molecular weight range of 1000-10000 Da were detected using ClinProt system and statistically different between adult patients with ALL and healthy controls. Quick classifier (QC) algorithm was used to obtain a diagnostic model consisting of five peptides that could discriminate patients with ALL from controls with a high sensitivity (100%) and specificity (96.67%). The peptides in the QC model were identified as fibrinogen alpha chain (FGA), glutathione S-transferase P1 (GSTP1), isoform 1 of fibrinogen alpha chain precursor, platelet factor 4 (PF4) by high pressure/performance liquid chromatography mass spectrometry/mass spectrometry. Relative intensities of the five peptides were compared among ALL different groups for the potential importance of MRD evaluation in ALL. The peptides with increased relative intensities in newly diagnosed (ND) ALL patients were found to be decreased in their relative intensities after complete remission (CR) of adult ALL. When ALL patients were refractory & relapsed (RR), relative intensities of the peptides were elevated again. Peptides with decreased relative intensities in ND and RR ALL patients were found to be increased in their relative intensities when ALL patients achieved CR. The findings were validated by ELISA and western blot. Further linear regression analyses were performed to eliminate the influence of platelet and white blood cell counts on serum protein contents and indicated that there were no correlations between the contents of all four proteins (PF4, connective tissue active peptide III, FGA and GSTP1) and white blood cell or platelet counts in ALL different groups and healthy control.

CONCLUSIONS

We speculate the five peptides, FGA, isoform 1 of fibrinogen alpha chain precursor, GSTP1, PF4 and connective tissue active peptide III would be potential biomarkers for forecasting relapse, monitoring MRD and evaluating therapeutic response in adult ALL.

MYC deregulation in lymphoid tumors: molecular mechanisms, clinical consequences and therapeutic implications

MYC is one of the most frequently deregulated oncogenes in human malignancies. It encodes a leucine zipper transcription factor that modulates a broad spectrum of cellular genes responsible for enhancing cell proliferation, cellular metabolism, growth, angiogenesis, metastasis, genomic instability, stem cell self-renewal and reduced differentiation. MYC functions predominantly as an amplifier of expression of already active genes, potentiating the pre-existing transcriptional program, although it can also repress certain transcriptional targets. In mouse models, MYC induces lymphomas, but requires cooperation with other lesions, including inactivation of the p53 pathway, structural alterations of BCL2 family members, or increased PI3K activity. In human B-cell tumors, MYC rearrangements involving the 8q24 region and immunoglobulin heavy or light genes are a hallmark of Burkitt lymphoma (BL), but can also occur in other lymphoid malignancies, that include diffuse large B-cell lymphoma (DLBCL), B-cell lymphoma, unclassifiable, with features intermediate between DLBCL and Burkitt lymphoma (BCLU), plasma cell myeloma (PCM), mantle cell lymphoma (MCL) and plasmablastic lymphoma. For non-BL lymphoid malignancies, MYC fusions represent secondary genetic events and exist in the context of complex karyotypes. Regardless of the mechanism deregulating MYC, lymphomas over-expressing MYC are addicted to this oncogene, highlighting the potential clinical utility of MYC targeting strategies. Several promising approaches for pharmaceutical intervention have been suggested which are now in preclinical or clinical development. Herein, we therefore review the molecular pathogenetic mechanisms associated with MYC deregulation in human B-cell lymphomas and their implications for therapies targeting MYC.

Clofarabine/cyclophosphamide for debulking before stem cell transplantation

BACKGROUND

Allogeneic haematopoietic stem cell transplantation (HSCT) is the only curative rescue therapy for patients (pts) with chemotherapy-refractory acute leukaemia. Disease control prior to HSCT is essential for long-term disease-free survival after HSCT.

PATIENTS AND METHODS

We have retrospectively analysed the outcome of 20 pts aged 21-64 years with refractory leukaemia (acute myeloid leukaemia, n = 16; acute lymphatic leukaemia, n = 4) who received debulking therapy with clofarabine (10 mg/m², days 1-4) and cyclophosphamide (200 mg/m², days 1-4; ClofCy) prior to HSCT.

RESULTS

Clofarabine/cyclophosphamide (1-4 cycles) was well tolerated and resulted in a substantial reduction of leukaemic cells in all pts. HSCT was performed in 15 of 20 pts. After HSCT (myeloablative, n = 9; dose-reduced, n = 6), all pts showed engraftment and full donor chimerism (related donors, n = 4 or unrelated donors, n = 11) and all pts achieved complete haematologic remission (CR). The median survival after HSCT is 531 days (range: 48-1462 days), and six pts are still alive after a median of 1245 days. Seven pts died after they had relapsed between days +152 and +1496. One patient died from acute graft-versus-host disease (day +48) and one from systemic fungal infection (day +87).

CONCLUSION

Clofarabine/cyclophosphamide is a novel effective treatment approach for pts with chemotherapy-refractory acute leukaemia prior to HSCT. Whether this novel debulking protocol leads to improved long-term outcome in pts with refractory leukaemias remains to be determined in forthcoming clinical studies.

Targeted therapy with monoclonal antibodies in acute lymphoblastic leukemia

PURPOSE OF REVIEW

To describe the current new targeted therapy with monoclonal and bispecific antibodies in adult acute lymphoblastic leukemia (ALL), to improve response rates and outcome.

RECENT FINDINGS

Blast cells in ALL express a variety of specific antigens, such as CD19, CD20, CD22, CD33 and CD52, and recently monoclonal antibodies (MoAbs) became available to target these antigens. The anti-CD20 MoAb rituximab has substantially improved the outcome in Burkitt lymphoma/leukemia, and is currently applied in de-novo B-precursor ALL. The MoAbs directed against CD22, linked to cytotoxic agents, either to calicheamicin (inotuzomab ozogamicin) or to plant or bacterial toxins (epratuzumab) are explored in refractory/relapsed childhood and adult ALL. Targeting CD19 is of great interest, as it is expressed in all B-lineage cells, including early precursors. The new bispecific antibody blinatumomab combines single chain antibodies to CD19 and CD3, and thereby T cells lyse the CD19 bearing B cells and is effective in patients with positive minimal residual disease (MRD) or refractory/relapsed ALL.

SUMMARY

Antibody therapy in ALL is very promising, with high rate of complete remission and MRD-negativity in advanced ALL. It is currently explored in de-novo ALL to establish the best setting in combination with chemotherapy or even as a monotherapy.

Murine models of acute leukemia: important tools in current pediatric leukemia research

Leukemia remains the most common diagnosis in pediatric oncology and, despite dramatic progress in upfront therapy, is also the most common cause of cancer-related death in children. Much of the initial improvement in outcomes for acute lymphoblastic leukemia (ALL) was due to identification of cytotoxic agents that are active against leukemia followed by the recognition that combination of these cytotoxic agents and prolonged therapy are essential for cure. Recent data demonstrating lack of progress in patients for whom standard chemotherapy fails suggests that the ability to improve outcome for these children will not be dramatically impacted through more intensive or newer cytotoxic agents. Thus, much of the recent research focus has been in the area of improving our understanding of the genetics and the biology of leukemia. Although in vitro studies remain critical, given the complexity of a living system and the increasing recognition of the contribution of leukemia extrinsic factors such as the bone marrow microenvironment, in vivo models have provided important insights. The murine systems that are used can be broadly categorized into syngeneic models in which a murine leukemia can be studied in immunologically intact hosts and xenograft models where human leukemias are studied in highly immunocompromised murine hosts. Both of these systems have limitations such that neither can be used exclusively to study all aspects of leukemia biology and therapeutics for humans. This review will describe the various ALL model systems that have been developed as well as discuss the advantages and disadvantages inherent to these systems that make each particularly suitable for specific types of studies.

Influence of interleukin-15 polymorphism on the survival of adult patients with acute lymphoblastic leukemia in Egypt

The aim of this study was to analyze the association of the rs10519612 and rs17007695 polymorphisms with the risk of acute lymphoblastic leukemia (ALL) and also to evaluate their impact on the survival of adult patients with ALL. The study included 164 adult patients with ALL and 158 healthy subjects as a control group who were genotyped for the interleukin-15 (IL-15) gene using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. We observed a higher risk of developing ALL for rs10519612 CC, rs17007695 TC and rs17007695 CC genotype carriers. There was increased risk for T-cell type in patients with the rs10519612 CC genotype. Notably, increased risk to develop B-cell type was found with rs17007695 TC and CC genotypes. There was no impact on overall survival or disease-free survival at 3 years. It is concluded that there is an association between both gene polymorphisms and the risk of ALL and with disease immunophenotype. However, there was no impact on the outcome of patients.

Clinical significance of minimal residual disease in young adults with standard-risk/Ph-negative precursor B-acute lymphoblastic leukemia: results of prospective study

Clinical risk classification is inaccurate in predicting outcome in adult patients with acute lymphoblastic leukemia (ALL), sometimes resulting in patients receiving inappropriate chemotherapy or stem cell transplantation. To identify complementary markers suitable for further treatment stratification in patients with standard-risk (SR)/philadelphia-negative (Ph-negative) precursor B-ALL, we evaluated the predictive value of minimal residual disease (MRD) after induction and consolidation chemotherapy in strictly defined SR/Ph-negative precursor B-ALL patients who were treated with a standard protocol using quantitative real-time polymerase chain reaction with the rearranged immunoglobulin heavy chain gene as a molecular marker. The cytologic complete response (CR) rate was 92.3 % after induction. At this time point, the molecular CR rate was 73.9%. Patients with molecular CR (MolCR) after induction had a significantly higher probability of disease-free survival (DFS; 78.8 vs 30.8%; P = .001) and of overall survival (OS; 82.4 vs 41.7%; P < .0001) compared to patients with molecular failure (MolFail). MRD at end consolidation had the same significance. Quantitative MRD assessment identified patients with MolFail after induction and/or consolidation as a high-risk group, with 3-year DFS and OS rates of 28.6 and 35.7%, respectively. Patients with MolCR after induction and consolidation were classified as low-risk and had 3-year DFS rate of 89.7% and OS rate of 93.3%. Thus, MRD quantification during treatment identified prognostic subgroups within the otherwise homogeneous SR/Ph-negative precursor B-ALL population who may benefit from individualized treatment.

B acute lymphoblastic leukemia with t(14;19)(q32;p13.1) involving IGH/EPOR: a clinically aggressive subset of disease

B acute lymphoblastic leukemia (B-ALL) with t(14;19)(q32;p13.1), in which IGH and EPOR are juxtaposed, has been reported rarely. We describe the clinicopathological features of six patients, three men and three women, with a median age of 39 years. Initial and follow-up bone marrow samples were examined from each patient. The clinical, morphologic, and immunophenotypic results were compared with data obtained from conventional cytogenetic analysis and by using home-brew fluorescence in situ hybridization (FISH) probes for IGH at 14q32 and EPOR at 19p13.1. The bone marrow specimens were hypercellular (median 90%; range 80-100%), with a median blast count of 90% (range 60-93%). Immunophenotypic analysis performed by flow cytometry demonstrated a stable, precursor B-cell immunophenotype. The t(14;19)(q32;p13.1) was present in all cases with morphologic evidence of disease. The translocation was stable and appeared morphologically subtle on conventional karyotypic analysis. Detection was facilitated using FISH, which confirmed IGH/EPOR rearrangement in all cases. All patients received aggressive multiagent chemotherapy as part of a variety of regimens. Four of six patients achieved an initial complete remission, but all relapsed. At last follow-up, five of six patients had died of disease (median survival, 12 months after diagnosis). We conclude that B-ALL associated with t(14;19)(q32;p13.1) is a distinctive form of disease that is associated with younger patient age and an aggressive clinical course.

Cell death sensitization of leukemia cells by opioid receptor activation

Cyclic AMP (cAMP) regulates a number of cellular processes and modulates cell death induction. cAMP levels are altered upon stimulation of specific G-protein-coupled receptors inhibiting or activating adenylyl cyclases. Opioid receptor stimulation can activate inhibitory G_i-proteins which in turn block adenylyl cyclase activity reducing cAMP. Opioids such as D,L-methadone induce cell death in leukemia cells. However, the mechanism how opioids trigger apoptosis and activate caspases in leukemia cells is not understood. In this study, we demonstrate that downregulation of cAMP induced by opioid receptor activation using the opioid D,L-methadone kills and sensitizes leukemia cells for doxorubicin treatment. Enhancing cAMP levels by blocking opioid-receptor signaling strongly reduced D,L-methadone-induced apoptosis, caspase activation and doxorubicin-sensitivity. Induction of cell death in leukemia cells by activation of opioid receptors using the opioid D,L-methadone depends on critical levels of opioid receptor expression on the cell surface. Doxorubicin increased opioid receptor expression in leukemia cells. In addition, the opioid D,L-methadone increased doxorubicin uptake and decreased doxorubicin efflux in leukemia cells, suggesting that the opioid D,L-methadone as well as doxorubicin mutually increase their cytotoxic potential. Furthermore, we found that opioid receptor activation using D,L-methadone alone or in addition to doxorubicin inhibits tumor growth significantly in vivo. These results demonstrate that opioid receptor activation via triggering the downregulation of cAMP induces apoptosis, activates caspases and sensitizes leukemia cells for doxorubicin treatment. Hence, opioid receptor activation seems to be a promising strategy to improve anticancer therapies.

Dorsal column myelopathy following intrathecal chemotherapy for acute lymphoblastic leukemia

OBJECTIVE/CONTEXT: To describe a distinctive clinical and radiographic pattern of myelopathy following intrathecal chemotherapy. Myelopathy is a rare complication of intrathecal chemotherapy used in the treatment of acute lymphoblastic leukemia (ALL). We present a 42-year-old female with T-cell ALL who developed a myelopathy primarily involving the dorsal columns.

METHOD

Case report and literature review.

FINDINGS

Within 24 hours of an injection of intrathecal methotrexate, cytarabine, and hydrocortisone, the patient developed ascending lower limb numbness and balance difficulties progressing to the inability to ambulate. Clinical examination showed profound loss of lower limb proprioception and light touch sensation below T5, mild proximal limb weakness, but preserved pinprick and temperature sensation with intact bowel and bladder function. Initial thoracic and lumbar spine magnetic resonance imaging (MRI) at 1 week revealed no abnormalities. However, repeat imaging at 6 weeks showed abnormal signal in the posterior cord with sparing of the anterior and lateral columns, diffusely involving the lower cervical cord through the conus medullaris. Dermatomal somatosensory-evoked potential (DSEP) conduction abnormalities were consistent with thoracic myelopathy. An empiric trial of high-dose intravenous corticosteroids during inpatient rehabilitation more than 6 weeks later produced no significant clinical improvement.

CONCLUSION/CLINICAL RELEVANCE

Preferential and persistent dorsal column myelopathy is a distinctive clinical and radiographic presentation of a rare complication of intrathecal chemotherapy. The MRI abnormalities were initially absent, but evolved to consist of multi-level spinal cord T2 and STIR hyperintensity with regional gadolinium enhancement. DSEPs more accurately reflected the clinical level of spinal cord dysfunction.

Results of inotuzumab ozogamicin, a CD22 monoclonal antibody, in refractory and relapsed acute lymphocytic leukemia

BACKGROUND

CD22 expression occurs in >90% of patients with acute lymphocytic leukemia (ALL). Inotuzumab ozogamicin, a CD22 monoclonal antibody bound to calicheamicin, is active in ALL.

METHODS

Patients with refractory-relapsed ALL received treatment with inotuzumab. The first 49 patients received single-dose, intravenous inotuzumab at doses of 1.3 to 1.8 mg/m2 every 3 to 4 weeks. In the next 41 patients, the schedule was modified to inotuzumab weekly at a dose of 0.8 mg/m2 on day 1 and at a dose of 0.5 mg/m2 on days 8 and 15, every 3 to 4 weeks, based on higher in vitro efficacy with more frequent exposure.

RESULTS

Ninety patients were treated; 68% were in salvage 2 or beyond. Overall, 17 patients (19%) achieved a complete response (CR), 27 (30%) had a CR with no platelet recovery (CRp), and 8 (9%) had a bone marrow CR (no recovery of counts), for an overall response rate of 58%. Response rates were similar for single-dose and weekly dose inotuzumab (57% vs 59%, respectively). The median survival was 6.2 months overall, 5.0 months with the single-dose schedule, and 7.3 months with the weekly dose schedule. The median survival was 9.2 months for patients in salvage 1 (37% at 1 year), 4.3 months for patients in salvage 2, and 6.6 months for patients in salvage 3 or later. The median remission duration was 7 months. Reversible bilirubin elevation, fever, and hypotension were observed less frequently on the weekly dose. In total, 36 of 90 patients (40%) underwent allogeneic stem cell transplantation. Veno-occlusive disease was noted in 6 of 36 patients after stem cell transplantation (17%), was less frequent after the weekly schedule (7%), and with less alkylators in the preparative regimen.

CONCLUSIONS

Inotuzumab single-agent therapy was highly active, safe, and convenient in patients with refractory-relapsed ALL. A weekly dose schedule appeared to be equally effective and less toxic than a single-dose schedule.

Novel agents and biomarkers for acute lymphoid leukemia

New genetic markers for adult acute lymphoblastic leukemia (ALL) have been found to have prognostic impact, such as the lymphoid transcription factor gene IKZF1 alterations, which are associated with a high rate of leukemic relapse in B-ALL. Although complete remission rates by induction chemotherapy in ALL are now high, the long-term survival is still disappointing. Improvements in the survival outcome of ALL have been observed in young adults as a result of the use of pediatric inspired regimens and the broadening of the number of patients who are eligible for allogeneic SCT. Development of new and less toxic agents also provide promise to improve the outcome in adult ALL, such as tyrosine kinase inhibitors in Ph-positive ALL, rituximab in CD20-positive disease, blinatumomab in precursor B-ALL and nelarabine in T-lineage ALL. Challenges for the future are to implement genomic profiling into the clinical setting to guide risk stratification and providing novel targets for tailored therapies.

Novel therapeutic strategies in adult acute lymphoblastic leukemia--a focus on emerging monoclonal antibodies

The outcomes in adult B-cell acute lymphoblastic leukemia (ALL) remain inferior to those achieved in pediatric populations. Targeted therapy with monoclonal antibodies may improve outcomes in adult B-cell ALL without significant additive toxicity. Rituximab is the best known monoclonal antibody and is routinely used in combination chemo-immunotherapy for treatment of adult B-cell ALL and Burkitts leukemia. A number of other monoclonal antibodies are currently under investigation for treatment of adult B-cell ALL including unconjugated antibodies (eg., ofatumumab, alemtuzumab and epratuzumab), antibodies conjugated to cytotoxic agents (eg., inotuzumab ozogamycin and SAR3419), antibodies conjugated to toxins such Pseudomonas or Diptheria toxins (eg., BL22 and moxetumomab pasudotox), and T-cell engaging bi-specific antibodies that redirect cytotoxic T lymphocytes to lyse target ALL cells (eg., blinatumomab). In this article we review the therapeutic implications, current status and results of monoclonal antibody-based therapy in adult B-cell ALL.

Monitoring of minimal residual disease (MRD) is useful to predict prognosis of adult patients with Ph-negative ALL: results of a prospective study (ALL MRD2002 Study)

BACKGROUND

Allogeneic hematopoietic stem cell transplantation (HSCT) for patients with Philadelphia chromosome (Ph)-negative acute lymphoblastic leukemia (ALL) in first complete remission (CR1) is much more intensive than multi-agent combined chemotherapy, although allogeneic HSCT is associated with increased morbidity and mortality when compared with such chemotherapy. Minimal residual disease (MRD) status has been proven to be a strong prognostic factor for adult patients with Ph-negative ALL.

METHODS

We investigated whether MRD status in adult patients with ALL is useful to decide clinical indications for allogeneic HSCT. We prospectively monitored MRD after induction and consolidation therapy in adult patients with Ph-negative ALL.

RESULTS

Of 110 adult ALL patients enrolled between July 2002 and August 2008, 101 were eligible, including 59 Ph-negative patients. MRD status was assessed in 43 patients by the detection of major rearrangements in TCR and Ig and the presence of chimeric mRNA. Thirty-nine patients achieved CR1, and their probabilities of 3-year overall survival and disease-free survival (DFS) were 74% and 56%, respectively. Patients who were MRD-negative after induction therapy (n = 26) had a significantly better 3-year DFS compared with those who were MRD-positive (n = 13; 69% vs. 31%, p = 0.004). All of 3 patients who were MRD-positive following consolidation chemotherapy and did not undergo allogeneic HSCT, relapsed and died within 3 years after CR.

CONCLUSIONS

These results indicate that MRD monitoring is useful for determining the clinical indications for allogeneic HSCT in the treatment of ALL in CR1.

HLA-G expression in acute lymphoblastic leukemia: a significant prognostic tumor biomarker

Human leukocyte antigen G (HLA-G) is a non-classical major histocompatibility class Ib antigen with multiple immune regulatory functions including the induction of immune tolerance in malignancies. The goal of our study was to investigate the expression of membrane form of HLA-G in acute lymphoblastic leukemia (ALL) before and after therapy in a trial to evaluate its role as a tumor escape mechanism and prognosis. So we measured its expression by reverse transcription (RT)-PCR in peripheral blood mononuclear cells of 25 (ALL) patients and 15 healthy controls and correlated our findings with a variety of clinical and laboratory variables and two important cytokines, IL-10 and INF-γ, and with natural killer (NK) cells. Serum levels of IL-10 and INF-γ were measured by ELISA. NK cells were quantitated by flow cytometry. The best cutoff values for the investigated markers were determined by ROC curve. The current study showed that membrane-bound HLA-G expression levels and positivity rates above the cutoff value 0.37 were significantly higher in ALL patients at diagnosis compared to after therapy and both showed significant higher levels than in normal control group (P < 0.01). Moreover, IL-10 and INF-γ serum levels were significantly elevated in ALL patients at time of diagnosis compared to healthy controls with a significant reduction in their levels in ALL patients after receiving chemotherapy. Membrane HLA-G expression showed a significant positive correlation with lactate dehydrogenase, peripheral and bone marrow blast cells and with IL-10 and INF-γ. The positive correlation of membrane HLA-G expression with both IL-10 and INF-γ serum levels supports the speculation that both cytokines may be involved in the control of HLA-G expression. HLA-G showed a negative correlation with NK cells confirming its importance in tumor escape through down-regulation of NK cells. In conclusion, HLA-G expression could be used as a prognostic tumor marker to monitor disease state and improvement in ALL.

Feasibility of allografting in patients with advanced acute lymphoblastic leukemia after salvage therapy with inotuzumab ozogamicin

BACKGROUND

No highly effective salvage therapy exists for patients with relapsed acute lymphoblastic leukemia (ALL). Inotuzumab ozogamicin (IO) is a CD22 monoclonal antibody attached to calicheamycin that targets B lymphocytes in early stages of development, successfully inducing remission in patients with multiply relapsed ALL.

METHODS

We describe our findings in 26 patients who received allogeneic hematopoietic stem cell transplantation (SCT) after treatment with IO between September 2010 and October 2011.

RESULTS

Patients with a median age of 33 years (range, 5-70 years) received an allogeneic matched sibling donor (n = 9), matched- or 1-antigen mismatched unrelated donor (n = 16), or cord blood donor SCT (n = 1) while in complete remission (n = 23) or with active disease (n = 3). At the time of SCT, 15 patients were in complete remission without evidence of minimal residual disease (MRD) measured by multiparameter flow cytometry. Patients were heavily pretreated, including 5 patients who had received previous allogeneic SCT. Patients received a median of 3 courses of IO (range, 1-5 courses) before SCT. Seven patients are alive at a median follow-up of 13 months (range, 5-16 months), with 1-year event-free and overall survival (OS) of 22% and 20%, respectively. Patients without MRD at time of SCT had a markedly better 1-year OS of 42%. The cumulative incidence of nonrelapse mortality (NRM) at 6 months and 1 year were 40% and 60%, respectively, with 5 deaths attributed to venoocclusive disease (VOD).

CONCLUSIONS

Treatment with IO allows more patients to undergo transplantation while in remission, with favorable overall survival in patients without MRD who undergo transplantation. Reduction in hepatic toxicity is needed to improve overall results.

The microtubule targeting agent PBOX-15 inhibits integrin-mediated cell adhesion and induces apoptosis in acute lymphoblastic leukaemia cells

Although recent decades have seen an improved cure rate for newly diagnosed paediatric acute lymphoplastic leukaemia (ALL), the treatment options for adult ALL, T-cell ALL (T-ALL) and relapsed disease remain poor. We have developed a novel series of pyrrolo-1,5-benzoxazepine (PBOX) compounds and established their anticancer efficacy in a variety of human tumour cell types. Here, we demonstrate that PBOX-15 inhibits cell growth, and induces G2/M cell cycle arrest and apoptosis in both T-ALL and B-cell ALL (B-ALL) cells. In addition, prior to PBOX-15-induced apoptosis, PBOX-15 decreases ALL cell adhesion, spreading and migration. Concurrently, PBOX-15 differentially down-regulates β1-, β2- and α4-integrin expression in ALL cells and significantly decreases integrin-mediated cell attachment. PBOX-15 interferes with the lateral mobility and clustering of integrins in both B-ALL and T-ALL cells. These data suggest that PBOX-15 is not only effective in inducing apoptosis in ALL cells, but also has the potential to disrupt integrin-mediated adhesion of malignant lymphocytes, which represents a novel avenue for regulating leukaemic cell homing and migration.

Are incidence rates of adult leukemia in the United States significantly associated with birth cohort?

BACKGROUND

Leukemia is a common cancer among U.S. adults but there are few established risk factors. If leukemia risks are substantially influenced by exposures that vary in prevalence across generations, then population incidence rates should vary significantly by birth cohort. However, prior studies have not examined leukemia birth cohort effects using contemporary data and methods.

METHODS

We used incidence data from the National Cancer Institute's Surveillance, Epidemiology and End Results Program from 1992 through 2009 for adults 25-84 years old and age period cohort models to estimate incidence rate ratios according to birth cohort for acute myeloid leukemia (AML), acute lymphoid leukemia (ALL), chronic myeloid leukemia (CML), and chronic lymphoid leukemia (CLL).

RESULTS

Leukemia incidence varied significantly between birth cohorts for each major leukemia type in men and women except female AMLs; changes on the order of 1% per birth year or 20% per generation were observed. The most significant birth cohort signatures were observed for CLLs and AMLs in men, which were decreasing and increasing, respectively, in cohorts born since 1946.

CONCLUSIONS

Our results support the hypothesis that adult leukemia risks are significantly modulated by environmental and lifestyle exposures.

IMPACT

A number of well-established (smoking, certain chemicals, radiation) and newly recognized (obesity) leukemia risk factors are modifiable; ultimately, efforts to promote healthy lifestyles might also help reduce incidence rates of adult leukemia.

Long-term follow-up of the imatinib GRAAPH-2003 study in newly diagnosed patients with de novo Philadelphia chromosome-positive acute lymphoblastic leukemia: a GRAALL study

We report here the results of the GRAAPH-2003 trial with long-term follow-up in 45 patients with de novo Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL). Imatinib-based strategy improved the 4-year overall survival (OS) up to 52% versus 20% in the pre-imatinib LALA-94 trial (P = .0001). Despite the selection in patients who actually underwent transplantation, these results suggest that allogeneic or autologous stem cell transplants (SCTs) still have a place in overcoming the poor prognosis of Ph+ ALL in the era of imatinib therapy. OS was 50% after allogeneic SCT (24 patients), 33% in patients without a transplantation (9 patients), and 80% after autologous SCT (10 patients without allogeneic donor or >55 years, including 7 patients in complete molecular response).

Methylenetetrahydrofolate reductase polymorphisms and risk of acute lymphoblastic leukemia-evidence from an updated meta-analysis including 35 studies

Background

5,10-methylenetetrahydrofolate reductase (MTHFR) variants, C677T and A1298C, have been reported to be associated with decreased risk of acute lymphoblastic leukemia (ALL). However, results derived from individually underpowered studies are conflicting. We carried out an updated meta-analysis on the association between MTHFR polymorphisms and ALL risk.

Methods

Relevant publications were searched through PUBMED and EMBASE databases. The associations between MTHFR C677T and A1298C polymorphisms and the risk of ALL were evaluated by odds ratios (ORs). The heterogeneity and publication bias were estimated. Meta-regression analysis was performed to evaluate the potential sources of heterogeneity.

Results

C677T polymorphism was associated with a reduced risk of ALL (allele contrast: OR_RE = 0.91, 95% CI: 0.83-0.99). Subgroup analysis showed MTHFR C677T variant was associated with decreased susceptibility to ALL in children and Caucasians. Meta-regression showed the logOR for the association between T allele and ALL increased as sex ratio (M/F) in the case group increased (P = 0.01). Regarding A1298C polymorphism, no significant association was observed (allele contrast: OR_RE = 1.01, 95% CI: 0.91-1.11). There was no publication bias for C677T or A1298C polymorphism.

Conclusions

The present meta-analysis suggests that the C677T polymorphism, not A1298C, in MTHFR gene is associated with a decreased risk of ALL, particularly among children and Caucasians subjects. Our findings suggest that the influence of the C677T polymorphism on ALL susceptibility is modified by sex ratio in cases (M/F). Since folate intake may be a possible confounding factor, including this factor in future prospective studies is warranted. Further meta-analysis studies should be at least stratified for folate levels and gender to give more powerful and informative results.

B-cell acute lymphoblastic leukemia with t(4;11)(q21;q23) in a young woman: evolution into mixed phenotype acute leukemia with additional chromosomal aberrations in the course of therapy

About 5% of adult B-cell acute lymphoblastic leukemias (B-ALL) are characterized by t(4;11)(q21;q23), which confers peculiar features to this B-ALL subtype, including a very immature immunophenotype and poor prognosis. We describe the case of a 21-year-old female who presented with B-ALL carrying the t(4;11)(q21;q23) and blasts positive for CD19, TdT, CD79a, CD38, HLA-DR. Before completing the Hyper-CVAD (hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone) therapy regimen, the B-cell leukemic clone still was detected, but an additional leukemic clone appeared, with morphology and immunophenotype (CD13, CD33, CD64, CD38, CD56, CD15, CD4(dim)) compatible with derivation from the myeloid/monocytic lineage. Karyotype showed the co-existence of three cell lines, with persistence of t(4;11)(q21;q23) and appearance of +8,+12,+13 and two der(4). The patient died because of disseminated intravascular coagulation. Our report describes a rare, possible evolution of such a subtype of B-ALL, with transformation into mixed phenotype acute leukemia in the course of therapy. This finding suggests a blast cell derivation from a common lymphoid/monocytic precursor leading to a final bilineal acute leukemia.

Treatment of Philadelphia chromosome-positive acute lymphoblastic leukaemia with imatinib combined with a paediatric-based protocol

Although the combination of tyrosine kinase inhibitors with chemotherapy is widely used for young adults with Philadelphia chromosome positive-acute lymphoblastic leukaemia (Ph+ ALL), the outcome and safety of this combination using intensive paediatric-based protocols has not been well described. The clinical course of 32 adults age 18-60 years with Ph+ ALL treated with a paediatric-based protocol plus imatinib was evaluated. The complete response rate was 94%. Grade 3-4 infections, neuropathy, myopathy and liver function abnormalities were common, resulting in major treatment delays and dose reductions, and declines in performance status (physical deconditioning), particularly in patients aged 41-60 years. Median and 3-year overall survival (OS) was 40·7 months and 53%, respectively, and median and 3-year even-free survival (EFS) was 30·1 months and 50%, respectively. OS and EFS were inferior in deconditioned patients. Of 16 patients who underwent haematopoietic stem cell transplantation (HSCT) in first complete remission, six died of non-relapse complications. There was no significant difference in OS and EFS between transplanted and non-transplanted patients, based on an intention-to-treat and time-to-donor identification analysis. The combination of imatinib with a paediatric-based regimen in adults produced high response rates, but was associated with considerable toxicity and high non-relapse mortality post-HSCT.

Acute leukaemia: making sense of a complex blood cancer

Acute leukaemia represents a diverse group of blood cancers that affect both children and adults. Treatment schedules for these haematology cancers are often prolonged, with many associated side effects and complications. Nurses caring for patients with acute leukaemia require an anticipatory approach, where care is aimed at minimizing the side effects of treatment and being constantly vigilant for any impending adverse effects. Moreover, patients require support for the psychosocial issues that can arise for patients during their illness. This article provides an overview of acute lymphoblastic leukaemia and acute myeloid leukaemia. Nursing considerations in the care of patients being treated for acute leukaemia are also explored.

Synergy of sequential administration of a deglycosylated ricin A chain-containing combined anti-CD19 and anti-CD22 immunotoxin (Combotox) and cytarabine in a murine model of advanced acute lymphoblastic leukemia

The outcome for patients with refractory or relapsed acute lymphoblastic leukemia (ALL) treated with conventional therapy is poor. Immunoconjugates present a novel approach and have recently been shown to have efficacy in this setting. Combotox is a mixture of two ricin-conjugated monoclonal antibodies (RFB4 and HD37) directed against CD19 and CD22, respectively, and has shown activity in pediatric and adult ALL. We created a murine xenograft model of advanced ALL using the NALM/6 cell line to explore whether the combination of Combotox with the cytotoxic agent cytarabine (Ara-C) results in better outcomes. In our model the combination of both low- and high-dose Combotox and Ara-C resulted in significantly longer median survival. Sequential administration of Ara-C and Combotox, however, was shown to be superior to concurrent administration. These findings have led to a phase I clinical trial exploring this combination in adults with relapsed or refractory B-lineage ALL (ClinicalTrials.gov identifier NCT01408160).

High curability via intensive reinduction chemotherapy and stem cell transplantation in young adults with relapsed acute lymphoblastic leukemia in Sweden 2003-2007

BACKGROUND

A minority of patients with adult acute lymphoblastic leukemia who relapse are rescued. The aim of this population-based study was to assess the results of reinduction treatment and allogeneic stem cell transplantation in patients in second complete remission.

DESIGN AND METHODS

Between 2003-2007, 76 adults (<66 years) with relapsed acute lymphoblastic leukemia (Burkitt's leukemia excluded) were prospectively reported to The Swedish Adult Acute Leukemia Registry and later evaluated.

RESULTS

Reinduction with: (i) mitoxantrone, etoposide, and cytarabine (MEA); (ii) fludarabine, cytarabine, pegylated-asparaginase plus granulocyte colony-stimulating factor (FLAG-Asp); and (iii) cytarabine, betamethasone, cyclophosphamide, daunorubicin, and vincristine (ABCDV) resulted in complete remission in 6/9 (67%), 10/16 (63%) and 9/21 (43%) of the patients, respectively. Allogeneic stem cell transplantation was performed during second complete remission in 29 patients. Multivariate analysis regarding overall survival after relapse revealed that age over 35 years at diagnosis and relapse within 18 months were negative prognostic factors. Overall survival rates at 3 and 5 years were 22% (95% CI: 13-32) and 15% (95% CI: 7-24). Of 19 patients less than 35 years at diagnosis who underwent allogeneic stem cell transplantation in second remission, ten (53%) are still alive at a median of 5.5 years (range, 4.2-8.3) after relapse, whereas all patients over 35 years old at diagnosis have died.

CONCLUSIONS

Allogeneic stem cell transplantation remains the treatment of choice for young adults with relapsed acute lymphoblastic leukemia. Both (i) mitoxantrone, etoposide, and cytarabine and (ii) fludarabine, cytarabine, pegylated-asparaginase plus granulocyte colony-stimulating factor seem effective as reinduction treatments and should be further evaluated. New salvage strategies are needed, especially for patients over 35 years old at diagnosis.

Inotuzumab ozogamicin, an anti-CD22-calecheamicin conjugate, for refractory and relapsed acute lymphocytic leukaemia: a phase 2 study

BACKGROUND

The outlook for patients with refractory and relapsed acute lymphocytic leukaemia (ALL) is poor. CD22 is highly expressed in patients with ALL. Inotuzumab ozogamicin is a CD22 monoclonal antibody conjugated to the toxin calecheamicin. We did a phase 2 study to assess the efficacy of this antibody.

METHODS

We recruited patients at the MD Anderson Cancer Center, Houston, TX, USA, between June, 2010, and March, 2011. Adults and children with refractory and relapsed ALL were eligible. Ten adults were treated before enrolment of children started. Patients were given 1·8 mg/m(2) inotuzumab ozogamicin intravenously over 1 h every 3-4 weeks (the first three adults and three children received 1·3 mg/m(2) in the first course). The primary endpoint was overall response (complete response or marrow complete response with no recovery of platelet count or incomplete recovery of neutrophil and platelet counts). Analysis was done by intention to treat. This study is registered, number NCT01134575.

FINDINGS

49 patients were enrolled and treated. Median age was 36 years (range 6-80). CD22 was expressed in more than 50% of blasts in all patients. The median number of courses was two (range one to five) and the median time between courses was 3 weeks (range 3-6). Nine (18%) patients had complete response, 19 (39%) had marrow complete response, 19 (39%) had resistant disease, and two (4%) died within 4 weeks of starting treatment. The overall response rate was 57% (95% CI 42-71). The most frequent adverse events during course one of treatment were fever (grade 1-2 in 20 patients, grade 3-4 in nine), hypotension (grade 1-2 in 12 patients, grade 3 in one), and liver-related toxic effects (bilirubin: grade 1-2 in 12 patients, grade 3 in two; raised aminotransferase concentration: grade 1-2 in 27 patients, grade 3 in one).

INTERPRETATION

Inotuzumab ozogamicin shows promise as a treatment for refractory and relapsed ALL.

FUNDING

Pfizer.

A clinically adaptable method to enhance the cytotoxicity of natural killer cells against B-cell malignancies

BACKGROUND AIMS

Retroviral transduction of anti-CD19 chimeric antigen receptors significantly enhances the cytotoxicity of natural killer (NK) cells against B-cell malignancies. We aimed to validate a more practical, affordable and safe method for this purpose.

METHODS

We tested the expression of a receptor containing CD3ζ and 4-1BB signaling molecules (anti-CD19-BB-ζ) in human NK cells after electroporation with the corresponding mRNA using a clinical-grade electroporator. The cytotoxic capacity of the transfected NK cells was tested in vitro and in a mouse model of leukemia.

RESULTS

Median anti-CD19-BB-ζ expression 24 h after electroporation was 40.3% in freshly purified (n =18) and 61.3% in expanded (n = 31) NK cells; median cell viability was 90%. NK cells expressing anti-CD19-BB-ζ secreted interferon (IFN)-γ in response to CD19-positive target cells and had increased cytotoxicity. Receptor expression was detectable 6 h after electroporation, reaching maximum levels at 24-48 h; specific anti-CD19 cytotoxicity was observed at 96 h. Levels of expression and cytotoxicities were comparable with those achieved by retroviral transduction. A large-scale protocol was developed and applied to expanded NK cells (median NK cell number 2.5 × 10(8), n = 12). Median receptor expression after 24 h was 82.0%; NK cells transfected under these conditions exerted considerable cytotoxicity in xenograft models of B-cell leukemia.

CONCLUSIONS

The method described here represents a practical way to augment the cytotoxicity of NK cells against B-cell malignancies. It has the potential to be extended to other targets beyond CD19 and should facilitate the clinical use of redirected NK cells for cancer therapy.

Aberrant methylation and decreased expression of the RIZ1 gene are frequent in adult acute lymphoblastic leukemia of T-cell phenotype

Retinoblastoma protein-interacting zinc finger, RIZ1, is a tumor suppressor gene that is inactivated in various solid tumors. However, the role of the RIZ1 gene has not been well examined in adult acute lymphoblastic leukemia (ALL). We analyzed the expression and promoter methylation status of the RIZ1 gene in patients with newly diagnosed ALL by quantitative real-time reverse transcription polymerase chain reaction (PCR) and methylation-specific PCR, respectively. RIZ1 expression in 67 cases of ALL (mean 1.043) was decreased compared with that in normal bone marrow (mean 1.471) (p = 0.030). Methylation was detected in 11 of 71 patients (15.5%) but not in healthy controls. Methylation was associated with decreased RIZ1 expression in many ALL cases examined, but this was not statistically significant. In T-ALL, RIZ1 methylation was more frequent (63.6%) than in B-ALL (6.7%) (p < 0.0001) and the decrease of RIZ1 expression was more significant than in B-ALL (p = 0.045). 5-Aza-2'-deoxycytidine treatment of MOLT-4 cells with RIZ1 methylation induced demethylation of RIZ1 and restoration of expression. Forced RIZ1 expression in T-ALL cell lines suppressed cell growth accompanied by G2/M arrest and apoptosis. No mutations were found by PCR-single strand conformation polymorphism analysis in hotspots of the gene. These results suggest that RIZ1 is inactivated in adult ALL, and this inactivation is associated with methylation in T-ALL.

A comprehensive cytogenetic classification of 1466 Chinese patients with de novo acute lymphoblastic leukemia

Cytogenetics and molecular cytogenetics of 1466 Chinese patients with de novo acute lymphoblastic leukemia (ALL) were studied. Cytogenetic results were available in 1175 patients. Cross-correlations of 23 subclasses of cytogenetic abnormalities were described. Childhood cases had higher incidences of normal karyotype, t(1;19), +8, 12q-, +21, +22 and high hyperdiploidy with 51-65 chromosomes, and lower incidences of t(9;22) and -5/5q- than adult ones (all p<0.05). Relationships of cytogenetic subclasses with immunophenotyping subgroups of ALL were studied. Our study presents the cytogenetic characteristics of a large series of Chinese ALL patients.

An auto-SCT-based total therapy resulted in encouraging outcomes in adolescents and young adults with acute lymphoblastic leukemia: report from a single center of China

Application of auto-SCT in the post-remission therapy for adolescents and young adults (AYAs) with ALL is controversial. We analyzed the outcomes of 79 AYAs (15-24 years) with ALL who received our designed total therapy protocol with auto-SCT in first CR from 1990 to 2009. The estimated OS and EFS at 5 years for the cohort were 62.8±5.9 and 61.5±5.7%. The cumulative non-relapse mortality and relapse rate at 5 years for the cohort were 7.2±3.1 and 33.6±5.8%. Time to CR >4 weeks was the only independent unfavorable factor associated with OS, EFS and relapse in multivariate analysis. Patients in standard risk (SR) group and high risk (HR) group had better OS (78.3±7.4, 63.8±10.2 vs 38.1±11.6%) and EFS (78.0±7.4, 63.4±9.4 vs 32.4±11.3%), and lower relapse rate (15.9±6.5, 31.5±9.5 vs 65.7±11.8%) compared with patients in very high risk (VHR) group. Our data confirmed that auto-SCT-based total therapy might be an optional treatment strategy for AYAs with ALL in SR. Patients in HR also could get benefit from such schedule. But for those in VHR, allogenetic SCT is still the prior recommendation for the frequent recurrence after auto-SCT.

Vascular access devices in leukemia: a retrospective review amongst patients treated at the Ottawa Hospital with induction chemotherapy for acute leukemia

Patients with acute leukemia require reliable central vascular access to ensure delivery of intravenous therapy. Peripherally inserted central catheters (PICCs) and Hickman(®) catheters are two commonly inserted central vascular catheters (CVCs), providing access to the central vascular space. While there have been reports describing individual center experiences, no one has compared the two devices, retrospectively or prospectively. We analyzed patients diagnosed with acute leukemia between September 1996 and April 2009, who had a PICC or Hickman®, received induction chemotherapy and survived at least 20 days. Prior to 1 January 2007, PICCs were inserted by palpation (PICC-palp) and Hickman(®) catheters were inserted surgically (H-Surg). After this date, PICCs were inserted by ultrasound (PICC-U/S) and Hickman(") catheters were inserted by interventional radiology (H-IR). Fifty-five patients had a Hickman(®) catheter (18 H-Surg, 37 H-IR) and 92 patients had a PICC (69 PICC-palp, 23 PICC-U/S). Significant improvements from H-Surg to H-IR catheters include the reduction in exit-site inflammation and infection (27.8% to 5.4%) and in bacteremic episodes (72.2% to 27.0%). Compared to PICC-U/S, H-IR had fewer cases of thrombophlebitis (0.0% vs. 8.7%); H-IR also required fewer instillations of a thrombolytic agent than the PICC-U/S (8.1% vs. 69.6%). Both CVCs have shown improvements from pre- to post-2007 insertion methods. Our data suggest that there were fewer complications with post-2007 Hickman(®) catheters compared to PICCs, suggesting that Hickman® catheters provide a more reliable central vascular access in these patients.

Advances in acute lymphoblastic leukemia in adults

PURPOSE OF REVIEW

This review will be focused on the advances in adult acute lymphoblastic leukemia (ALL) based on recently published articles.

RECENT FINDINGS

Progress in the understanding of the molecular basis of ALL has contributed to a more precise definition of risk factors. The study of minimal residual disease has re-defined the baseline prognostic factors and has opened new strategies for postremission management. The use of pediatric-inspired therapies for young adults with standard-risk ALL, the broadening of the number of patients who are eligible for allogeneic stem cell transplantation, the increasing use of targeted therapies (monoclonal antibodies, tyrosine kinase inhibitors, and new purine analogs, etc.) in early phases of the disease, together with the improvements in supportive therapy explain the increased survival of young and middle-aged adult ALL.

SUMMARY

These changes are improving long-term outcome, which in ongoing studies is expected to be of close to 50%, and are opening the door for future therapeutic advances.

Myc roles in hematopoiesis and leukemia

Hematopoiesis is a process capable of generating millions of cells every second, as distributed in many cell types. The process is regulated by a number of transcription factors that regulate the differentiation along the distinct lineages and dictate the genetic program that defines each mature phenotype. Myc was first discovered as the oncogene of avian leukemogenic retroviruses; it was later found translocated in human lymphoma. From then on, evidence accumulated showing that c-Myc is one of the transcription factors playing a major role in hematopoiesis. The study of genetically modified mice with overexpression or deletion of Myc has shown that c-Myc is required for the correct balance between self-renewal and differentiation of hematopoietic stem cells (HSCs). Enforced Myc expression in mice leads to reduced HSC pools owing to loss of self-renewal activity at the expense of increased proliferation of progenitor cells and differentiation. c-Myc deficiency consistently results in the accumulation of HSCs. Other models with conditional Myc deletion have demonstrated that different lineages of hematopoietic cells differ in their requirement for c-Myc to regulate their proliferation and differentiation. When transgenic mice overexpress c-Myc or N-Myc in mature cells from the lymphoid or myeloid lineages, the result is lymphoma or leukemia. In agreement, enforced expression of c-Myc blocks the differentiation in several leukemia-derived cell lines capable of differentiating in culture. Not surprising, MYC deregulation is recurrently found in many types of human lymphoma and leukemia. Whereas MYC is deregulated by translocation in Burkitt lymphoma and, less frequently, other types of lymphoma, MYC is frequently overexpressed in acute lymphoblastic and myeloid leukemia, through mechanisms unrelated to chromosomal translocation, and is often associated with disease progression.

Dasatinib as first-line treatment for adult patients with Philadelphia chromosome-positive acute lymphoblastic leukemia

Dasatinib is a potent BCR-ABL inhibitor effective in chronic myeloid leukemia and Ph(+) acute lymphoblastic leukemia (ALL) resistant/intolerant to imatinib. In the GIMEMA LAL1205 protocol, patients with newly diagnosed Ph(+) ALL older than 18 years (with no upper age limit) received dasatinib induction therapy for 84 days combined with steroids for the first 32 days and intrathecal chemotherapy. Postremission therapy was free. Fifty-three patients were evaluable (median age, 53.6 years). All patients achieved a complete hematologic remission (CHR), 49 (92.5%) at day 22. At this time point, 10 patients achieved a BCR-ABL reduction to < 10(-3). At 20 months, the overall survival was 69.2% and disease-free survival was 51.1%. A significant difference in DFS was observed between patients who showed at day 22 a decrease in BCR-ABL levels to < 10(-3) compared with patients who never reached these levels during induction. In multivariate analysis, BCR-ABL levels of < 10(-3) at day 85 correlated with disease-free survival. No deaths or relapses occurred during induction. Twenty-three patients relapsed after completing induction. A T315I mutation was detected in 12 of 17 relapsed cases. Treatment was well tolerated; only 4 patients discontinued therapy during the last phase of the induction when already in CHR. In adult Ph(+) ALL, induction treatment with dasatinib plus steroids is associated with a CHR in virtually all patients, irrespective of age, good compliance, no deaths, and a very rapid debulking of the neoplastic clone.

Effects of Toll-like receptor signals in T-cell neoplasms

T-cell neoplasms have poor prognosis and few effective therapeutic options. Therefore, identification of factors in T-cell leukemia/lymphoma that are associated with cancer progression may represent novel therapeutic targets. Recent studies have highlighted a previously unappreciated role for the expression of Toll-like receptors (TLRs) on T cells and their effects on cell survival and proliferation. TLRs can bind exogenous molecules derived from pathogens as well as endogenous self-ligands released from damaged cells. Recent reports demonstrate that TLR engagement on primary mouse or human T cells enhances proliferation and/or cell survival. The mechanisms by which TLR stimulation on T cells influences these parameters and the different T-cell subsets that are affected by TLR stimulation are currently under investigation. Furthermore, neither the biological importance of stimulating TLRs on neoplastic T cells nor the prevalence of TLR expression in T-cell malignancies have yet to be characterized. Based on published reports and compelling preliminary data, we propose that the activation of the TLR-MyD88 signaling pathway in neoplastic T cells contributes to disease progression by reducing cell death and enhancing cell division. In this article, we present both theoretical arguments and experimental data in support of this hypothesis.

Targeting survivin overcomes drug resistance in acute lymphoblastic leukemia

Relapse of drug-resistant acute lymphoblastic leukemia (ALL) has been associated with increased expression of survivin/BIRC5, an inhibitor of apoptosis protein, suggesting a survival advantage for ALL cells. In the present study, we report that inhibition of survivin in patient-derived ALL can eradicate leukemia. Targeting survivin with shRNA in combination with chemotherapy resulted in no detectable minimal residual disease in a xenograft model of primary ALL. Similarly, pharmacologic knock-down of survivin using EZN-3042, a novel locked nucleic acid antisense oligonucleotide, in combination with chemotherapy eliminated drug-resistant ALL cells. These findings show the importance of survivin expression in drug resistance and demonstrate that survivin inhibition may represent a powerful approach to overcoming drug resistance and preventing relapse in patients with ALL.

Outcomes of phenylketonuria with relevance to follow-up

Currently, there is no international consensus on how patients with phenylketonuria (PKU) (or milder forms of hyperphenylalaninaemia) should be followed in clinical practice. Guidelines concerning the frequency and type of assessments that should be made according to age usually focus on blood phenylalanine concentrations. A need exists for improved guidelines on how to do the follow-up of individuals with PKU/milder forms of hyperphenylalaninaemia. An interdisciplinary approach for monitoring patients is required, involving relevant clinical investigations and regular contact with a clinician and dietician/nutritionist as well as contact with social health worker, psychologist and neurologist, at least at request. This chapter presents a scheme for follow-up. However, by no means this scheme aims to present the one for all time follow-up programme. The scheme for follow-up may rather serve as a start for further discussion in larger groups of professionals in collaboration with patients and their parents. A number of questions remain unanswered, and further research is still needed to fine-tune the management of PKU at different ages.

A retrospective study of leukemia epidemiology in Northern Tunisia

A hospital-based epidemiological study of leukemia was carried out in the northern part of Tunisia during a 5-year period, from 1999 to 2003. Of 402 Tunisians diagnosed with leukemia, 344 (85.6%) had acute leukemia and 58 (14.4%) had chronic leukemia. Age-specific incidence rates for acute lymphoid leukemia (ALL), acute myeloid leukemia (AML), chronic lymphoid leukemia (CLL) and chronic myeloid leukemia (CML) are described. The distribution of leukemia in the governorate of Nabeul was established. These results are useful for the organization and follow-up of medical care.