Philadelphia positive acute lymphoblastic leukaemia of childhood

B-Cell Precursor-Acute Lymphoblastic Leukemia With EBF1-PDGFRB Fusion Treated With Hematopoietic Stem Cell Transplantation and Imatinib: A Case Report and Literature Review

A 9-year-old girl was diagnosed with B-cell precursor-acute lymphoblastic leukemia (BCP-ALL). Although she entered remission after induction therapy, she relapsed 15 months after maintenance therapy cessation. Since further investigation revealed EBF1-PDGFRB fusion, her condition was treated as BCR-ABL1-like acute lymphoblastic leukemia. She was started on a tyrosine kinase inhibitor, imatinib, and chemotherapy and underwent umbilical cord blood transplantation following reduced intensity conditioning. She has remained in complete remission for 36 months after cord blood transplantation. This case demonstrates the successful use of a tyrosine kinase inhibitor to treat BCP-ALL with a fusion transcript and highlights the need for a standardized treatment protocol.

Demographics and Outcome of Philadelphia-positive ALL in a Pediatric Population in North India: a Single-center Experience

Philadelphia-positive (Ph+) acute lymphoblastic leukemia (ALL) in children had a worse outcome before the use of tyrosine kinase inhibitors. We have evaluated the demographics and outcome of Ph+ ALL patients treated with imatinib without blood marrow transplantation. Of the 206 children with ALL registered for treatment, the demographic data of 15 Ph+ ALL patients were compared with the remaining Ph- patients. Imatinib (340 mg/m) was started on day 5 (D5) of induction in Ph+ patients, and their overall survival was compared with Ph- high-risk patients treated on similar protocols. Statistical analysis was carried out by the Fisher exact test and the t test. The Kaplan-Meier test was used for survival analysis. Philadelphia positivity noted in 15/206 (7.28%) ALL patients was higher than reported earlier. Median initial total leukocyte count and central nervous system positivity were significantly higher in Ph+ patients. Myeloid markers, CD13 and CD33, were also positive in 33.3% Ph+ patients. D15 and D35 marrow showed remissions in a larger proportion of Ph+ ALL, as compared with Ph- patients, but chemotherapy interruptions and neutropenic deaths were significantly higher after starting imatinib, as compared with Philadelphia high-risk patients. Overall survival was similar in Ph+ and Ph- high-risk ALL patients. Ph+ ALL, noted in 7.28%, presented with high initial white blood cell counts, high central nervous system positivity, poor steroid response, and higher induction deaths, as compared with high-risk Ph- ALL, and raised the question about the appropriate dose and time of introduction of imatinib to prevent toxicity.

Evaluation of Cytogenetic Abnormalities in Patients with Acute Lymphoblastic Leukemia

Acute lymphoblastic leukemia (ALL) accounts for 20% of all adult leukemias and is the most common leukemia during childhood (80%). We present data on cytogenetics of ALL from a tertiary centre in India correlating it with clinical factors. Karyotyping of bone marrow samples of 204 patients with newly diagnosed ALL was performed with standard G-banding technique. Clinical data of patients was obtained from case records. Survival was estimated using Kaplan-Meir curves and compared by the log-rank test. Univariate and multivariate analysis was done for survival with age, sex, immunophenotype, hyperleukocytosis, risk type, remission status and cytogenetics. The most common karyotypes observed were normal in 39.7% (N = 81), hyperdiploidy in 12.7% (N = 26), t(9;22) in 4.4% (N = 9), t(1;19) in 3.9% (N = 8). Adults with ALL had worse survival compared with pediatric patients (HR 3.62; 2.03-6.45 95% CI, p < 0.001). Patients not in morphologic remission after induction chemotherapy fared poorly (HR 4.86; 2.67-8.84 95% CI, p < 0.001). Patients with favourable cytogenetics had better overall survival (HR 0.36; 0.12-1.05 95% CI, p < 0.05). On multivariate analysis, achievement of morphologic remission emerged as single most significant predictor of survival (p < 0.001). MLL gene rearrangement and t(12;21) were seen less commonly as compared to Western data. However, incidence rates of various cytogenetic abnormalities were similar to that reported from other centres from India. Age, morphologic remission at end of induction chemotherapy and favourable cytogenetics correlated significantly with survival.

Diagnostic evaluation of RNA sequencing for the detection of genetic abnormalities associated with Ph-like acute lymphoblastic leukemia (ALL)

Philadelphia (Ph)-like acute lymphoblastic leukemia (ALL) is a molecular subtype of high-risk B-cell ALL characterized by formation of abnormal gene fusions involving tyrosine kinase (TK) and cytokine receptor genes and activation of TK signaling. Because of the diversity of associated genetic changes, the detection of Ph-like ALL cases currently requires multiple cytogenetic and molecular assays; thus, our goal was to develop a consolidated workflow for detecting genetic abnormalities in Ph-like ALL. We found that total and targeted RNA sequencing (RNAseq)-based approach allowed the detection of abnormal fusion transcripts (EBF1-PDGFRB, P2RY8-CRLF2, RCSD1-ABL1, and RCSD1-ABL2). The bioinformatics algorithm accurately detected the fusion transcripts without prior input about possible events. Additionally, we showed that RNAseq analysis enabled evaluation for disease-associated sequence variants in expressed transcripts. While total RNAseq can be a second tier approach allowing discovery of novel genetic alterations, the targeted RNAseq workflow offers a clinically applicable method for the detection of fusion transcripts.

Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia Is Separated into Two Subgroups Associated with Survival by BCR-ABL Fluorescence in situ Hybridization of Segmented Cell Nuclei: Report from a Single Institution

Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) may include the lymphoid blast crisis of chronic myeloid leukemia (CML-BC). We applied fluorescence in situ hybridization (FISH) of the BCR-ABL fusion gene to peripheral blood and/or bone marrow smears to determine whether the fusion was restricted to mononuclear cell nuclei or if segmented cell nuclei representing mature neutrophils also carried the fusion (Seg-FISH). Among 20 patients with Ph+ ALL without a prior diagnosis of CML, 9 were Seg-FISH+ and 11 were Seg-FISH-. Seg-FISH+ cases were characterized by a higher rate of p210-type BCR-ABL transcripts, higher white cell and blast counts, and a higher rate of myeloid and T-lymphoid antigen expression than Seg-FISH- cases, in addition to 'major route' cytogenetic abnormalities associated with CML-BC. Eighteen patients were treated with tyrosine kinase inhibitors (TKIs) either alone or in combination with multiagent chemotherapy, and 7 underwent allogeneic hematopoietic stem cell transplantation. Progression-free and overall survivals were greater in the Seg-FISH+ group than in the Seg-FISH- group. These results suggest that the Seg-FISH+ group represents lymphoid CML-BC that occurs de novo, while the Seg-FISH- represents Ph+ ALL in the strict sense, and the two groups are associated with survival when treated with TKIs or TKI-combined therapy.

Curcumin potentiates the anti-leukemia effects of imatinib by downregulation of the AKT/mTOR pathway and BCR/ABL gene expression in Ph+ acute lymphoblastic leukemia

Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) is triggered by BCR/ABL and SRC family tyrosine kinases. They interact with each other and subsequently activate downstream growth-signaling pathways, including Raf/MEK/ERK, Akt/mTOR, and STAT5 pathways. Although imatinib is the standard treatment for Ph+ leukemia, response rate of Ph+ ALL to imatinib is low, relapse is frequent and quick. Studies have documented the potential anti-tumor activities of curcumin. However, whether curcumin can be used in the therapy for Ph+ ALL remains obscure. Here, we reported that curcumin induced apoptosis by inhibition of AKT/mTOR and ABL/STAT5 signaling, down-regulation of BCR/ABL expression, and induction of the BCL2/BAX imbalance. Curcumin exerted synergetic anti-leukemia effects with imatinib by inhibition of the imatinib-mediated overactivation of AKT/mTOR signaling and down-regulation of BCR/ABL gene expression. In primary samples from Ph+ ALL patients, curcumin inhibited cellular proliferation and down-regulated constitutive activation of growth-signaling pathways not only in newly diagnosed patients but also in imatinib-resistant patients. In Ph+ ALL mouse models, curcumin exhibited synergetic anti-leukemia effects with imatinib. These results demonstrated that curcumin might be a promising agent for Ph+ ALL patients.

Haematological complete remission by ponatinib and bortezomib in a patient with relapsed, Ph⁺ pre-B acute lymphoblastic leukaemia

A 74-year-old man was previously diagnosed with BCR-ABL1-positive pre-B cell acute lymphoblastic leukaemia (pre-B ALL) based on bone marrow cytology, flow cytometry, cytogenetics and fluorescent in situ hybridisation findings. Following a highly complicated hospital course, the patient achieved cytogenetic remission by consolidated chemotherapy and the tyrosine kinase inhibitor dasatinib. He subsequently presented with relapsed pre-B ALL after 3 years in remission. In consideration of his challenging clinical history, he was started on concurrent ponatinib (45 mg daily) and bortezomib (1.3 mg/m(2) intravenous weekly). The major molecular response was achieved (<0.0893% BCR-ABL1 transcripts) after 3 months. Bone marrow now demonstrates a BCR-ABL1-negative, complete cytogenetic response. The patient continues to do well with mild thrombocytopenia and improved anaemia on bortezomib and 30 mg daily ponatinib. Our experience with a single patient suggests the feasibility of combined targeted therapy with ponatinib and bortezomib. This novel treatment approach achieved clinical remission with a manageable toxicity profile.

SMYD2 is highly expressed in pediatric acute lymphoblastic leukemia and constitutes a bad prognostic factor

Acute lymphoblastic leukemia (ALL) is the most common childhood malignancy. Although several clinical characteristics can be associated with worse prognosis, more robust biological markers still remains uncovered. SMYD2, a member of SMYD protein family, regulates the activity of several proteins through methylation. In this study, we performed quantitative real time PCR to compare the expression of SMYD2 in 83 pediatric ALL patients and non-neoplastic bone marrow samples (BMS). The study revealed that SMYD2 expression is altered in ALL BMS and its high expression was correlated with a bad prognosis. Moreover, we also revealed that SMYD2 expression level significantly decreases in patients that respond to chemotherapy treatment.

Oridonin in combination with imatinib exerts synergetic anti-leukemia effect in Ph+ acute lymphoblastic leukemia cells in vitro by inhibiting activation of LYN/mTOR signaling pathway

Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) is triggered by constitutively activated BCR-ABL and SRC family tyrosine kinases.They account for the activations of multiple growth-signaling pathways, including Raf/MEK/ERK, Akt/mTOR and STAT5 pathways. The BCR-ABL tyrosine kinase inhibitor imatinib is the standard treatment for Ph+ leukemia and plays efficacious role in CML. However, imatinib has few inhibitory effects on SRC tyrosine kinase with response rate of Ph+ ALL lower and relapse more frequent and quicker compared with CML. Previous studies showed that oridonin inhibits proliferation and induces apoptosis in many tumor cells. However, the anticancer activity and mechanism of oridonin in Ph+ ALL is unknown. To investigate the anticancer activity of oridonin, we examined its role in constitutively activated Akt/mTOR, Raf/MEK/ERK, STAT5 and SRC pathway, mRNA level of bcr/abl gene, cell viability and apoptosis in Ph+ ALL SUP-B15 cells. Furthermore, we detected synergetic effect of oridonin plus imatinib. Our results showed that oridonin inhibiting activations of LYN (one of SRC family kinases) and ABL and their downstream Akt/mTOR, Raf/MEK/ERK and STAT5 pathways, downregulated Bcl-2 but upregulated Bax protein and then induced apoptosis in Ph+ ALL cells. Oridonin plus imatinib exerted synergetic effects by overcoming imatinib defect of upregulating Akt/mTOR and LYN signaling. Additionally, we examined the effect of oridonin on the signaling pathways in the primary specimens from Ph+ ALL patients. Our data showed that oridonin remarkably suppressed activations of Akt/mTOR, Raf/MEK and STAT5 pathway in these primary specimens and oridonin with imatinib exerted synergetic suppressive effects on mTOR, STAT5 and LYN signaling in one imatinib resistant patient specimen. Additional evaluation of oridonin as a potential therapeutic agent for Ph+ ALL seems warranted.

Outcome of childhood acute lymphoblastic leukemia in Jordan

BACKGROUND

Accurate data about childhood acute lymphoblastic leukemia (ALL) in low- and middle-income countries are lacking. Our study is designed to assess survival of childhood ALL at King Hussein Cancer Center (KHCC) using modified St. Jude Children's Research Hospital protocols.

PATIENTS AND METHODS

We reviewed the medical records of children 1-18 years of age who were diagnosed with ALL and treated at KHCC from January 2003 through December 2009. Disease characteristics and outcome were analyzed.

RESULTS

Over a 7-year period, 300 children with ALL were treated. One hundred and seventy-three (57.7%) were males and 127 (42.3%) were females. The median age at diagnosis was 5 years. One hundred and fifty-seven (52.3%) children were classified as low-risk, 118 (39.3%) were standard-risk and 25 (8.3%) were high-risk. Two hundred and sixty-two (88.5%) children had pre-B cell phenotype and 34 (11.5%) had T-cell phenotype. Two hundred and seventy-three (91.3%) children were classified as having CNS I disease, 24 (8%) had CNS II, and 2 (0.67%) had CNS III. Cytogenetic abnormalities included: t(12;21) in 30 (12%) children and t(9;22) in 18 (7.4%). Four (1.3%) children died in induction, 6 (2%) died in first remission and 27 (9%) relapsed. After a median follow-up of 34.5 months (range 0.32-84.5), the estimated 5-year event free survival and overall survival were 80% and 89%, respectively.

CONCLUSION

Treatment protocols developed by major cooperative groups and institutions to treat childhood ALL was successfully adapted and suggest that such an approach may be useful in other low- and middle-income countries.

How I treat Philadelphia chromosome–positive acute lymphoblastic leukemia

The Philadelphia chromosome is present in approximately 20% to 30% of adults with acute lymphoblastic leukemia (ALL). The poor prognosis of this relatively uncommon acute leukemia has led to the rapid adoption of treatment strategies such as unrelated donor hematopoietic stem cell transplant and tyrosine kinase inhibitors into clinical practice, despite a relative paucity of randomized clinical trials. Recently, there has been a surge of interest in the underlying biology of ALL. In combination with an accumulation of more mature clinical study data in Philadelphia-positive ALL, it is increasingly possible to make more rational and informed treatment choices for patients of all ages. In this article, I review available data and indicate how I personally interpret current evidence to make pragmatic treatment choices with my patients, outside of clinical trials. My strongest recommendation is that all physicians who are treating this rare disease actively seek appropriate clinical trials for their patients wherever possible.

Treatment of Philadelphia-chromosome-positive acute lymphoblastic leukemia with imatinib in combination with chemotherapy

The presence of the Philadelphia chromosome (Ph) is associated with a very poor prognosis in acute lymphoblastic leukemia (ALL). Although hematologic complete remission (CR) is achieved in 50% to 80% of adult patients by intensive chemotherapy in multicenter studies, long-term outcome is dismal, with overall survival of approximately 10%. Currently, allogeneic hematopoietic stem cell transplantation (allo-SCT) is thought to be the only curative therapeutic modality for this leukemia in adults, but the long-term survival rates are about 40% or less, far from satisfactory. Imatinib mesylate, a recently introduced specific tyrosine kinase inhibitor of BCR-ABL, in combination with chemotherapy, resulted in more than 90% hematologic CR in adult Ph-positive ALL, including molecular CR in more than 50% of patients. The higher CR rate and less frequent relapse gave more patients a chance to receive SCT. Patients who did not qualify for allo-SCT because of the lack of a suitable donor, advanced age, or underlying medical conditions apparently showed better survival than historical control patients treated with chemotherapy alone. Although longer follow-up is required to determine the effect on survival, imatinib in combination with chemotherapy clearly has a major potential to improve the treatment of Ph-positive ALL and may cure a substantial proportion of patients without SCT.

Genetic aberrations in paediatric acute leukaemias and implications for management of patients

The process of malignant transformation in paediatric acute leukaemias is complex, requiring at least two deleterious events resulting in DNA damage. This damage ranges from point-mutations to double-strand DNA breaks leading to various types of chromosomal rearrangements. In this review we summarise the most common genetic aberrations for the three main subtypes of paediatric acute leukaemia: B-cell-precursor acute lymphoblastic leukaemia, T-cell acute lymphoblastic leukaemia and acute myeloid leukaemia. Several genetic aberrations are independent prognostic factors, and are now used in risk stratification for treatment. Molecular pathways activated by genetic aberrations could provide potential molecular targets for novel therapies. Some genetic aberrations represent sensitive targets for molecular detection of minimal residual disease. This provides hope for the development of targeted therapies, effective against leukaemic cells.

The treatment of pediatric Philadelphia positive (Ph+) leukemias in the imatinib era

BACKGROUND

As the treatment of Philadelphia positive (Ph+) leukemias in the era of imatinib continues to evolve, the role of allogeneic hematopoietic cell transplantation (allogeneic-HCT) in first remission is becoming more unclear.

PROCEDURE

Thirty-two pediatric centers across the United States and Canada were surveyed regarding current treatment practices for Ph+ acute lymphoblastic leukemia (ALL) and chronic myelogenous leukemia (CML). The survey addressed treatment approaches for Ph+ ALL and CML in terms of imatinib therapy and use of allogeneic-HCT.

RESULTS

Twenty-three of the 32 centers returned the survey to provide a 72% response rate. Of the 27 physicians responding to the survey, 22 (81%) recommended a matched sibling donor (MSD) allogeneic-HCT, when available, in first remission for Ph+ ALL compared to 17/27 (63%) for patients with first chronic phase CML. There was universal agreement among survey responders regarding the use of imatinib upfront in Ph+ ALL and CML patients while 13 of 27 (48%) physicians reported using imatinib as maintenance therapy post-HCT for Ph+ ALL compared to 9 of 27 (33%) for CML.

CONCLUSIONS

Although a treatment consensus did not exist based on the results of this small survey, current treatment practices for pediatric Ph+ ALL and CML appear to favor allogeneic-HCT when a MSD is available. The use of post-HCT imatinib as maintenance therapy to avoid relapse for either Ph+ ALL or CML remains uncertain and awaits future prospective studies.

Prospective outcome data on 267 unselected adult patients with Philadelphia chromosome-positive acute lymphoblastic leukemia confirms superiority of allogeneic transplantation over chemotherapy in the pre-imatinib era: results from the International ALL Trial MRC UKALLXII/ECOG2993

Prospective data on the value of allogeneic hematopoietic stem cell transplantation (alloHSCT) in Philadelphia chromosome-positive (Ph(+)) acute lymphoblastic leukemia (ALL) are limited. The UKALLXII/ECOG 2993 study evaluated the outcome of assigning alloHSCT with a sibling (sib) or matched unrelated donor (MUD) to patients younger than 55 years of age achieving complete remission (CR). The CR rate of 267 patients, median age 40, was 82%. Twenty-eight percent of patients proceeded to alloHSCT in first CR. Age older than 55 years or a pre-HSCT event were the most common reasons for failure to progress to alloHSCT. At 5 years, overall survival (OS) was 44% after sib alloHSCT, 36% after MUD alloHSCT, and 19% after chemotherapy. After adjustment for sex, age, and white blood count and excluding chemotherapy-treated patients who relapsed or died before the median time to alloHSCT, only relapse-free survival remained significantly superior in the alloHSCT group (odds ratio 0.31, 95% confidence interval 0.16-0.61). An intention-to-treat analysis, using the availability or not of a matched sibling donor, showed 5-year OS to be nonsignificantly better at 34% with a donor versus 25% with no donor. This prospective trial in adult Ph(+) ALL indicates a modest but significant benefit to alloHSCT. This trial has been registered with clinicaltrials.gov under identifier NCT00002514 and as ISRCTN77346223.

Bone-marrow relapse in paediatric acute lymphoblastic leukaemia

Marrow relapse is the major obstacle to cure for 10-15% of young patients with acute lymphoblastic leukaemia (ALL). Recent investigations into the biology of minimal residual disease indicate that many early relapses derive from residual cells present at first diagnosis, but some late relapses might represent new mutations in leukaemic cells not eliminated by conventional therapy. Treatment of marrow relapse involves higher doses and more intensive schedules of the drugs used for initial therapy with or without haemopoietic stem cell transplantation. In most reports, transplantation is better than continuation chemotherapy in early marrow relapse, but its role in later relapse is less clear. Current therapy cures 10% of patients with early marrow relapses and 50% of those with late relapses, but outcomes have changed little in the past two decades. Understanding the molecular biology of ALL underlies development of improved risk stratification and new therapies. Although better drugs are needed, introduction of new agents into clinical trials in paediatric disease has been difficult. Innovative trial designs and use of valid surrogate endpoints may expedite this process.

The treatment of adults with acute lymphoblastic leukemia

Despite the relatively low incidence of acute lymphoblastic leukemia (ALL) in adults, large national and international collaborations have recently improved our understanding of how to treat ALL in adults. This article documents and examines the current evidence base for a "state of the art" therapy in both Philadelphia chromosome-negative and -positive adult ALL. The article comments upon areas of therapeutic debate, such as the role of bone marrow transplantation. In particular, the controversial subject of whether the superior outcome seen in younger patients is predicated on disease biology or therapeutic strategy is examined closely. Promising approaches under development are also discussed.

Allogeneic haematopoietic stem cell transplant in Philadelphia-positive acute lymphoblastic leukaemia

ALL in which the Philadelphia (Ph) chromosome is detected is one of the few diseases in which there is almost unequivocal agreement that a matched sibling allogeneic haematopoietic stem cell transplant in first CR is the most appropriate therapy for patients within certain age limits. Extension of allogeneic stem cell transplant to patients without matched sibling donors or to older individuals is increasingly possible due to unrelated donors, umbilical cord blood and reduced-intensity conditioning regimens. Here, we carefully review evidence supporting current practice and examine recent evidence relating to the use of newer allogeneic transplant technologies in Ph-pos ALL. We explore the burgeoning literature on the role of tyrosine kinase inhibitors in this disease and summarize their impact on the transplant practice.

Comparison of intensive chemotherapy, allogeneic, or autologous stem-cell transplantation as postremission treatment for children with very high risk acute lymphoblastic leukemia: PETHEMA ALL-93 Trial

PURPOSE

The optimal postremission therapy for children with very high-risk (VHR) acute lymphoblastic leukemia (ALL) is not well established. This randomized trial compared three options of postremission therapy: chemotherapy and allogeneic or autologous stem-cell transplantation (SCT).

PATIENTS AND METHODS

All 106 VHR-ALL patients received induction with five drugs followed by intensification with three cycles of chemotherapy. Patients in complete remission (CR) with an HLA-identical family donor were assigned to allogeneic SCT (n = 24) and the remaining were randomly assigned to autologous SCT (n = 38) or to delayed intensification followed by maintenance chemotherapy up to 2 years in CR (n = 38).

RESULTS

Overall, 100 patients achieved CR (94%). With a median follow-up of 6.5 years, 5-year disease-free survival (DFS) and overall survival (OS) probabilities were 45% (95% CI, 37% to 54%) and 48% (95% CI, 40% to 57%), respectively. The three groups were comparable in the main pretreatment ALL characteristics. Intention-to-treat analysis showed no differences for donor versus no donor in DFS (45%; 95% CI, 27% to 65% v 45%; 95% CI, 37% to 55%) and OS (48%; 95% CI, 30% to 67% v 51%; 95% CI, 43% to 61%), as well as for autologous SCT versus chemotherapy comparisons (DFS: 44%; 95% CI, 29% to 60% v 46%; 95% CI, 32% to 62%; OS: 45%; 95% CI, 31% to 62% v 57%; 95% CI, 43% to 73%). No differences were found within the different subgroups of ALL and neither were differences observed when the analysis was made by treatment actually performed.

CONCLUSION

This study failed to prove that, when a family donor is available, allogeneic SCT produces a better outcome than autologous SCT or chemotherapy in children with VHR-ALL.

A proteomic study on human osteoblastic cells proliferation and differentiation

Changes in expression profiles for 17 proteins were ascertained in human mature osteoblasts compared to pre-osteoblasts (differentiation markers). A differential approach was used to highlight proteomic changes between human osteosarcoma cells and mature osteoblasts, showing a relative over-expression of 8 proteins (proliferation and tumor indicators), as well as under-expression of proteins also found down-regulated in pre-osteoblasts (specific markers of osteoblast differentiation). Our findings confirmed the differences between cell lines and primary human cell cultures and suggested caution on the use of osteosarcoma to study anti-osteoporotic drugs in humans.