Mature B-cell Acute Lymphoblastic Leukemia Research Articles

Profiling the activity of the para-caspase MALT1 in B-cell acute lymphoblastic leukemia for potential targeted therapeutic application.

B-cell acute lymphoblastic leukemia (B-ALL) remains a hard-to-treat disease with a poor prognosis in adults. Mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1) is a para-caspase required for B-cell receptor (BCR)-mediated NF-κB activation. Inhibition of MALT1 in preclinical models has proven efficacious in many B-cell malignancies including chronic lymphocytic leukemia, mantle cell lymphoma and diffuse large B-cell lymphoma. We sought to examine the role of MALT1 in B-ALL and determine the biological consequences of its inhibition. Targeting MALT1 with both Z-VRPR-fmk and MI-2 efficiently kills B-ALL cells independent of the cell-of-origin (pro, pre, mature) or the presence of the Philadelphia chromosome, and spares normal B cells. The mechanism of cell death was through apoptotic induction, mostly in cycling cells. The proteolytic activity of MALT1 can be studied by measuring its ability to cleave its substrates. Surprisingly, with the exception of mature B-ALL, we did not detect cleavage of MALT1 substrates at baseline, nor after proteasomal inhibition or following activation of pre-BCR. To explore the possibility of a distinct role for MALT1 in B-ALL, independent of signaling through BCR, we studied the changes in gene expression profiling following a 24-hour treatment with MI-2 in 12 B-ALL cell lines. Our transcriptome analysis revealed a strong inhibitory effect on MYC-regulated gene signatures, further confirmed by Myc protein downregulation, concomitant with an increase in the Myc degrader FBXW7. In conclusion, our evidence suggests a novel role for MALT1 in B-ALL through Myc regulation and provides support for clinical testing of MALT1 inhibitors in B-ALL.

Philadelphia chromosome-positive B-cell acute lymphoblastic leukemia with e1a3 BCR-ABL1 transcript in a Nigerian with sickle cell anemia: a case report

BackgroundThe occurrence of acute leukemia in patients with sickle cell anemia is uncommon. The Philadelphia chromosome is the hallmark of chronic myeloid leukemia. However, it may also be associated with acute lymphoblastic leukemia and acute myeloblastic leukemia. The common BCR-ABL1 transcripts seen in acute lymphoblastic leukemia are e1a2, e13a2, and e14a2, while other transcripts such as e1a3, e13a3, and e6a2 occur rarely. This report describes the presentation, management, and outcome of the occurrence of B-cell acute lymphoblastic leukemia with the rare e1a3 BCR-ABL1 transcript in a patient with sickle cell anemia.Case presentationA 19-year-old male Nigerian, a known sickle cell anemia patient was admitted on account of severe vaso-occlusive crisis. Examination revealed fever, palor, and jaundice. Full blood count showed anemia and leukocytosis. Peripheral blood and bone marrow smears revealed numerous large and small lymphoblasts in keeping with the L2 subtype of acute lymphoblastic leukemia based on the French–American–British classification. Further evaluation was in keeping with a diagnosis of BCR-ABL1-positive mature B-cell acute lymphoblastic leukemia associated with the rare e1a3 transcript. He was commenced simultaneously on induction chemotherapy and Imatinib while being prepared for allogeneic stem cell transplantation. However, he died six months after diagnosis from meningoencephalitis.ConclusionThe occurrence of acute lymphoblastic leukemia with a rare BCR-ABL1 e1a3 transcript in association with sickle cell anemia is uncommon and associated with poor prognosis.

Metabolic and Endocrin Complications of Pediatric, Adolescent and Young Adult Acute Lymphoblastic Leukemia: Single Centre Experience

Introduction: Metabolic and endocrine complications are common complications in the treatment of Acute Lymphoblastic Leukemia (ALL). Inappropriate anti-diuretic hormone (ADH) syndrome, diabetes mellitus, hypoglycemia, surrenal failure, hypercalcemia may ocur during the treatment. Obesity, growth retardation or pause and osteopenia are the most common complications. These complications are usually due to combined chemotherapeutic agents used during the treatment. In this study, we present the metabolic/endocrine complications which are observed during treatment of ALL patients at our center.Material -Metod: One hundred and ten patients who were diagnosed with ALL and treated with the ‘Children's Oncology Group’ (COG) protocol and follow-up in the Pediatric Hematology / Oncology Department of the Istanbul University Institute of Oncology were included in the study. We retrospectively analyzed the demographic characteristics of the patients and presence of metabolic/endocrin problems (hyperglycemia, hypoglycemia, hypothyroidism, hypercholesterolemia, obesity) during all treatment stages were recorded. Forty-five (40.9%) of the patients were female and 65 (59.1%) were male. Ninety-seven (88.2%) patients were pre-B-cell ALL, 1 (0.9%) patients were mature B-cell ALL, 11 (10%) patients were T-cell ALL and 1 (0.9%) patients were biphenotypic ALL. The median age of the patients were 7 years (range:1,5-23).Results: One hundred of the 110 patients whose all clinical data were obtained were included for the evaluation of the metabolic and endocrin complications. The metabolic and endocrine problems were detected in 16 (16%) patients in any phases of the treatment and 84 (84%) patients did not have any metobolic or endocrine problems during the treatment. Twelve (12%) of the 16 patients with metabolic and endocrine problems were in 1 phase and 4 (4%) in 2 phases. Totally, 23 problems were detected. All metabolic / endocrine problems that arise during treatment are shown in Table 1. Seven of them (30.4%) were in induction, 2 of them were in consolidation (8.8%), no problems were found in interim maintenance 1, 7 (30.4%) were in delayed intencification, Interim maintenance 2 and delayed intencification 2 did not show any problems, and 7 (30.4%) were seen in maintenance.Conclusion: In the treatment of ALL, endocrine and metabolic problems are frequently seen during and after treatment. In our study, 23 metabolic problems (hyperglycemia, hypoglycemia, hypothyroidism, hypertriglyceridemia, hypercholesterolemia, osteoporosis, obesity, hyperferritinemia, metabolic syndrome) were recorded in 16 (16%) of the patients. Our resuts suggest that metabolic complications that may occur in ALL treatment should be considered as well as the remission of the disease. Therefore, patients should be carefully evaluated for metabolic and endocrin problems in ALL treatment. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

MiR-26a-5p as a Reference to Normalize MicroRNA qRT-PCR Levels in Plasma Exosomes of Pediatric Hematological Malignancies

Plasma exosomal microRNAs (miRNAs) are considered as valid circulating biomarkers for cancer diagnosis and prognosis. Quantitative real-time polymerase chain reaction (qRT-PCR), the most commonly used technique to assess circulating miRNA levels, requires a normalization step involving uniformly expressed endogenous miRNAs. However, there is still no consensus on reference miRNAs for plasma exosomal miRNA abundance normalization. In this study, we identified a panel of miRNAs with stable abundance by analyzing public plasma exosome RNA-seq data and selected miR-486-5p, miR-26a-5p, miR-423-5p and miR191-5p as candidate normalizers. Next, we tested the abundance variation of these miRNAs by qRT-PCR in plasma exosomes of healthy donors and pediatric patients with anaplastic large cell lymphoma, Burkitt lymphoma, Hodgkin lymphoma and mature B-cell acute lymphoblastic leukemia. MiR-486-5p and miR-26a-5p showed the most stable levels, both between healthy controls and patients and among the malignancies analyzed. In light of previous reports on miRNA stability in different exosome isolation methods, our data indicated that miR-26a-5p is a bona fide reference miRNA for qRT-PCR normalization to evaluate miRNA abundance from circulating plasma exosomes in studies of hematological malignancies.

The Paracaspase MALT1 Acts Independently of Pre-B-Cell Receptor Signaling As a Key Factor in Leukemic Cell Survival in Precursor B-Cell Acute Lymphoblastic Leukemia

Despite a central role for B-cell receptor precursor (pre-BCR) pathway in precursor B-cell acute lymphoblastic leukemia (B-ALL), there is limited available data on therapies that aim to disrupt this pathway. Mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1) is a para-caspase required for BCR-mediated NF-κB activation. We recently showed that targeting MALT1 with the small molecule inhibitor MI2 is effective in CLL, including drug-resistant clones (Saba Can Res 2017). We sought to examine the role of MALT1 in B-ALL and determine the biological consequences of inhibiting its activity. First, we tested MALT1 expression by immunoblot in B-ALL using 17 cell lines representing the disease spectrum (7 pro-B: REH, SEMK2, TOM1, RS4;11, NALM21, Z119, BV173; 8 pre-B: HB11;19, NALM6, RCH-ACV, SMS-SB, 697, KASUMI2, KOPN8, HPB-NULL; and 2 mature/Burkitt: 2F7, RAJI), and found that MALT1 was expressed in all cell lines at different levels. To determine sensitivity to MALT1 inhibition we used two molecules: Z-VRPR-fmk, a highly selective MALT1 blocking peptide, and MI2, a small molecule MALT1 inhibitor. Z-VRPR-fmk resulted in a dramatic cell growth inhibition in most of our B-ALL cell lines, with appropriate positive (TMD8) and negative (K562) controls, independent of the cell-of-origin (pro, pre, mature) or the presence of the Philadelphia chromosome. We did not observe a clear correlation between MALT1 level and degree of sensitivity to Z-VRPR-fmk. Interestingly, the two ibrutinib-resistant cell lines RS4;11 and 697, were amongst the top sensitive cell lines to MALT1 inhibition. A similar pattern of cell sensitivity was observed when these cell lines were treated with MI2, resulting in an IC50 at 48h of 0.2 µM in RS4;11 and < 0.5 µM in other sensitive cell lines, which is consistent with published data in sensitive DLBCL cell lines (IC50, 0.2-0.5 µM), and our data on the CLL cell line MEC1 (IC50, 0.2 µM). We then tested freshly collected PBMCs from patients with various blood cancers presenting with a leukemic phase against serial dilutions of MI2 for 48h (7 B-ALL, 24 CLL, and 4 CML). In addition, we included normal B-cells collected from five volunteers. Interestingly, B-ALL samples showed the highest sensitivity to MI2, followed by CLL, while the rest were resistant. The proteolytic activity of MALT1 can be studied by measuring its ability to cleave its targets such as A20, CYLD, BCL10, Roquin, Regnase and RelB. Surprisingly, with the exception of the Burkitt cell line 2F7, we did not detect cleavage of these targets at baseline, nor after proteasomal inhibition with MG-132 or following crosslinking of pre-BCR with anti-IgM in pre-B ALL, the latter successfully increased AKT phosphorylation. The constitutive activation of MALT1 in 2F7 was effectively inhibited by Z-VRPR-fmk as determined by a marked reduction in targets cleavage concomitant with an increase in full length proteins. We are expanding the mature B-ALL cell line cohort to include TANOUE, BALL-1, DAUDI, GA-10, and NC-37 cell lines to further explore to role of MALT1 in this disease subset. Collectively, these data highly suggest distinct roles for MALT1 in B-ALL: pro and pre-B-ALL vs. mature B-ALL. To explore the possibility of distinct role for MALT1 in B-ALL, arguably independent of BTK and of signaling through BCR, we used RNA sequencing to determine the changes in gene expression profiling following a 24h treatment with Z-VRPR-fmk in 3 highly sensitive B-ALL cell lines (RS4;11, HPB-NULL, and 697). Out of 39,514 tested genes, there were 160 genes whose expression changed ≥ 2-fold at P < 0.05 (84 down- and 76 up-regulated). Gene Set Enrichment Analysis (GSEA) identified 34 Hallmark and Oncogenic Signatures gene sets relevant to B-ALL that were all downregulated by Z-VRPR-fmk (FDR < 10%, and normalized enrichment score (NES) ≥ 1.50). Among those gene sets, mTOR-S6K and TANK-binding kinase 1 (TBK1)-dependent gene signatures stood out as the most affected. MALT1 was shown to be involved in the ribosomal protein S6 phosphorylation through activation of mTOR/AKT signaling. Indeed, treatment with MI2 and Z-VRPR resulted in a significant decrease in S6 phosphorylation in RS4;11 and SEMK2. In conclusion, MALT1 plays a critical role in B-ALL survival likely through a novel mechanism that involves mTOR-S6K pathway, independently from pre-BCR/BCR signaling. Supported by a grant from the Ladies Leukemia League, Inc., of the Gulf South Region. Disclosures Saba: Kyowa Kirin: Consultancy; AbbVie: Consultancy; Janssen: Consultancy, Speakers Bureau; Pharmacyclics: Consultancy, Speakers Bureau. Melnick:Epizyme: Consultancy; Janssen: Research Funding; Constellation: Consultancy. Wiestner:Merck: Research Funding; Nurix: Research Funding; Pharmayclics: Research Funding; Acerta: Research Funding. Burger:AstraZeneca: Honoraria; Aptose Biosciences, Inc: Research Funding; Gilead Sciences: Research Funding; Janssen Pharmaceuticals: Consultancy, Honoraria; Pharmacyclics, an AbbVie company: Research Funding; BeiGene: Research Funding. Safah:Celgene: Speakers Bureau; Incyte: Speakers Bureau; Verastem: Honoraria, Speakers Bureau; Jazz: Speakers Bureau; Amgen: Honoraria, Speakers Bureau.

Clinical Analysis of 7 Children with Mature B-cell Acute Lymphoblastic Leukemia

To evaluate the efficacy of CCCG-BNHL-2015 protocol in treatment of children with mature B-cell acute lymphoblastic leukemia (mature B-ALL). Seven pediatric patients with newly diagnosed mature B-ALL were treated by CCCG-BNHL-2015 protocol (risk group R4) in Children's Hospital of Nanjing Medical University from November 2014 to January 2017. The median age of patients at initial diagnosis was 7.2 years (range 4.1 to 11.75 years) with a male predominance (5:2), the clinical characters were as follows: 4 cases combined with thoracic and/or abdominal lumps, only lymphonode was involved in 1 case, bone destruction was complicated in 2 cases and 1 case was complicated with central nervous system leukemia. In 2 children, tumor lysis syndrome appeared at early phase. The lactate dehydrogenase level at diagnosis of all patients extremely increased. All patients achieved complete remission after 2 to 4 courses of therapy. Two among them underwent autologous hematopoietic stem cell transplantation. One with primary central nervous system leukemia relapsed before the last course, then the treatment was abandoned. The rest of 6 patients survived with a median follow-up period of 14 months (ranged from 7 to 28 months), and suffered from different degrees of myelosuppression and infection. No one died from serious complications. The CCCG-BNHL-2015 protocol (risk group R4) shows better curative effect, higher safety and remission rate in childhood mature B-cell lymphoblastic leukemia.

The Role of Kappa and Lambda in Subclassification of B Cell Lymphoblastic Leukemia in Sudanese Patients Using Flow Cytometry

Background: B-cell Acute lymphoblastic leukemia (B-ALL) is a neoplasm of lymphoblasts which are of B-cell lineage typically composed of small to medium sized blast cells, moderately condensed to dispersed chromatin with scanty cytoplasm and inconspicuous nucleoli, involving the bone marrow and/or blood. Methods and materials: This is a prospective cross-sectional study in which 50 blood and/or bone marrow samples of newly diagnosed patients (B-ALL) were tested for immunophenotyping. All samples were prepared for surface and cytoplasmic markers including kappa and lambda human antibody for 10 minutes in dark place and then run by the Flow Cytometer. Results: 64% of the study populations were males and 36% were females. Cases were classified according to immunophenotype and the age into different subtypes and showed the following frequencies: Pro B-ALL (8%), early pre B-ALL (56%), common B-ALL (16%), Pre-B-ALL (14%) and Mature B-ALL (only 6%). Surface immunoglobulin was positive in 10% and negative in 90% of all patients, showing 100% positivity in mature B-ALL and totally negative in other subtypes. While cytoplasmic immunoglobulin was positive in 16% and negative in 84% of all patients and was positive in 100% of Pre-B-ALL and in 50% of mature B-ALL. Surface kappa was more expressed in mature B-ALL than lambda giving a ratio of 2:1, while cytoplasmic kappa:lambda was 6:1 in Pre-B-ALL. Conclusion: Kappa and lambda have important role in B-ALL classification which necessitates their presence in immunophenotyping of B-ALL.

Treatment of children with highly suspected mature B-cell lymphoblastic leukemia

Objective To evaluate the outcomes of mature B-cell acute lymphoblastic leukemia(mature B-ALL)and to assess the safety and efficacy of the treatment protocol. Methods From February of 2003 to December of 2012, 15 children were diagnosed as mature B-cell acute lymphoblastic leukemia/lymphoma possible (mature B-ALL/NHLp) in Shanghai Children's Medical Center(SCMC) were enrolled, and they were treated with SCMC-mature B-ALL/NHLp-2003 protocol .All of the clinical characteristics, therapeutic effects and long-term outcomes were analyzed.The statistical data were processed by SPSS 21.0. Results The median age on diagnosis was 8.7 years (1 year and 5 months to 14 years and 4 months). Among them, 4 cases presented with local mass including maxillofacial tumors, neck and abdominal mass.The others had systemic manifestations such as fever and pale face. These neoplastic cells retained the expressions of surface membrane immunoglobulin M, terminal deoxynucleotidyl transferase, Cμ, CD10, CD19, cCD79a differently.Follow-up was updated to November 30, 2013.The median follow-up period was 80 months(39-128 months). Theestimated 5-year event free survival rate was (80.0±10.3)%.According to univariate analysis, increased lactate dehydrogenase level (> 4-times the normal value), increased serum ferritin level (> 2-times the normal value), no small residual disease markers were indepen-dent poor prognostic factors(χ2=5.49, 4.89, 5.49, all P<0.05). Conclusions SCMC-mature B-NHL/ALLp-2003 protocol is feasible and safe for children with mature B-ALL/NHLp, but more sample cases need to be investigated. Key words: Mature B-cell acute lymphoblastic leukemia/lymphoma; Child; Curative effect; Event-free survival

IN VITRO DRUG RESISTANCE IN CHILDHOOD MATURE B-CELL ACUTE LYMPHOBLASTIC LEUKEMIA

B a c k g r o u n d . Mature B-cell acute lymphoblastic leukemia (B-ALL) is a rare type of leukemia in children and counts for 1-2% of all leukemia cases. Pediatric B-ALL is treated according to protocols for non-Hodgkin lymphomas. O b j e c t i v e . The aim of the study was to analyze the in vitro drug resistance in children with B-ALL compared to ALL with other phenotypes. M a t e r i a l a n d m e t h o d s . A total number of 15 children with B-ALL (6 girls and 9 boys, median age 8 years, range 1.9-15 years) were included into the analysis. The in vitro drug resistance tests on leukemic cells were performed by means of the MTT assay. The results of B-ALL patients were compared to those obtained in patients with pre- B/common ALL (479 cases), pro-B-ALL (31cases) and T-ALL (87 cases). Results: B-ALL cells were more resistant than pre-B/common-ALL cells to dexamethasone and idarubicin. In comparison to pro-B-ALL phenotype, B-ALL blasts were more resistant to idarubicin and more sensitive to treosulfan. No significant differences were found in the in vitro drug resistance between B-ALL and T-ALL. Blasts of T-ALL were more resistant than pre-B/common-ALL cells to most of tested drugs. Conclusion: From the clinical point of view, B-ALL cells have similar in vitro drug sensitivity when compared to T-ALL, and higher drug resistance to dexamethasone than pre-B/common-ALL.

Outcome of Pediatric-Type Therapy for Philadelphia Chromosome-Negative Acute Lymphoblastic Leukemia (ALL) in Adolescents and Young Adults (AYA): A Study by the Japan Adult Leukemia Study Group (JALSG ALL202-U study)

AbstractAbstract 1464▪▪This icon denotes a clinically relevant abstract Background:Retrospective studies have shown that AYA with ALL treated with pediatric protocols have better outcomes than similarly aged patients with adult protocols, but prospective studies comparing AYA with pediatric schedules are scarce. So, we conducted a phase II multicenter study (JALSG ALL202-U) in collaboration with the Japan Association of Childhood Leukemia Study (JACLS) to determine the efficacy and safety of pediatric type therapy (JACLS ALL-02-HR). Methods:From June 2002 to September 2009, patients (age range 16–24 years) with previously untreated ALL (excluding Philadelphia-positive ALL and mature B-cell ALL) were consecutively registered in this study. For patients with t (4; 11), allogeneic stem cell transplantation (HSCT) was recommended during their first complete remission (CR), if donors were available; whereas for patients without t (4; 11), there were no criteria for choosing HSCT. This protocol consisted of induction therapy (pre-phase with oral corticosteroids and 5-drug induction), consolidation phase including 1) consolidation therapy, 2) sanctuary therapy with two cycles of high dose MTX, 3) reinduction therapy, 4) reconsolidation therapy and 2-year maintenance therapy. Intrathecal chemotherapy was administered during each cycle. In comparison with the former JALSG ALL-97 adult protocol, the pediatric-type therapy showed an increase in cumulative dose of CPM (1.5-fold), VCR (1.2-fold), L-asp (18-fold) and MTX (3.7-fold), respectively. As for the intrathecal chemotherapy, the duration was longer (ALL97; 4 to 21 week, ALL202; 1 to 94 week) and the frequency was increased from 8 to 15 times. Results:There were 138 eligible patients: median age was 19 years old and 56% were male. Of the eligible patients, 134 patients (97.1%) achieved CR. The estimated the 4-year OS rate was 74% and 4-year DFS rate was 71%, respectively. Compared with previous JALSG ALL-97 study, CR rate (97.1% ALL202, 84% ALL97; p=0.01), 4-year DFS rate (fig 1, 71% ALL202, 46% ALL97; p=0.0001) and 4-year OS rate (fig 2, 74% ALL202, 46% ALL97; p=0.0002) were significantly higher in this study. During induction therapy, major grade III-IV adverse events (AEs) were FN, DIC, pancreatitis and AST/ALT. The frequency of FN was higher with ALL202-U protocol (43%) than with ALL-97 protocol (12%). During consolidation phase and maintenance therapy, the most common toxicity was FN. The treatment duration during induction therapy and consolidation phase was longer than planned. In comparison with the outcome of JACLS ALL-02-HR protocol, grade 3 to 4 AEs were similar. Conclusion:This pediatric-type therapy was very efficient, yielding a 97.1% CR rate, 71% 4-year DFS and 74% 4-year OS in AYA patients. The protocol was tolerable, but FN and treatment prolongation were observed. Grade 3 to 4 AEs were similar to pediatric group. The data reported here were collected at the time of interim analysis. The latest data including AEs are currently being reviewed and will be disclosed at the presentation. [Display omitted] [Display omitted] Disclosures:No relevant conflicts of interest to declare.

In Vitro Effects of PI3Kδ Inhibitor GS-1101 (Cal-101) in Acute Lymphoblastic Leukemia (ALL)

AbstractAbstract 3534Acute lymphoblastic leukemia (ALL) is a highly heterogeneous disease. B-cell acute lymphoblastic leukemia (B-ALL) is characterized by uncontrolled proliferation of immature lymphoid blasts with suppression of normal hematopoiesis. Phosphoinositide 3-kinases (PI3K) transmit activation signals from diverse transmembrane receptors, leading to generation of phosphatidylinositol- 3,4,5-trisphosphate (PIP3) which promotes proliferation, differentiation, migration, and survival in lymphocytes and various other cell types. A knockout mouse model of the PI3K isoform p110δ demonstrates a unique role of p110δ (PI3Kδ) in B cell receptor (BCR) signaling. This is corroborated by clinical efficacy of the PI3Kδ inhibitor GS-1101 in mature B cell malignancies, especially in chronic lymphocytic leukemia (CLL). In contrast to mature B cell malignancies, expression and function of PI3Kδ in B-ALL has not been well characterized. We therefore analyzed PI3Kδ expression and effects of the PI3Kδ inhibitor GS-1101 in B-ALL.To screen efficacy of GS-1101 in B-ALL subsets, we performed viability and proliferation assays, using a panel of B-ALL cell lines, derived from different B-cell development stages (Pro-B: REH, RS4;11, Nalm-20, Nalm-21, TOM-1; Pre-B: Nalm-6, Kasumi-2, KOPN-8, SMS-SB, RCH-ACV, 697; Mature: Tanoue, Ball-1 unknown: CCRF-SB). A key downstream effector of PI3K is the serine/threonine kinase Akt, whose phosphorylation is used as a common readout of PI3K activation status. Western Blot analysis of the 15 cell lines showed almost identical levels of phospho-Akt (Ser473) in all tested cell lines, suggesting constitutive PI3K activity. To investigate the ability of GS-1101 to inhibit B-ALL cell proliferation, we performed cell growth experiments. Among the pre-B cell lines 4 of 6 showed a marked decrease in proliferation, 2 other pre-B cell lines showed a minor decrease. In contrast, none of the pro-B or mature B-ALL cell lines were affected by GS-1101. To explore the effects of GS-1101 on cell cycle of B-ALL cells, cell lines were treated with GS-1101 at concentrations ranging from 0.5μM to 5μM. In accordance with the cell growth experiments, G1 phase arrest and reduced numbers of S phase cells were detected in pre-B cell lines after GS-1101 treatment, but not in the pro-B or mature B cell lines. Next, we examined GS-1101 effects on metabolism of B-ALL cells via XTT (sodium 2,3,-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)-carbonyl]-2H-tetrazolium inner salt) staining. Cell lines were treated with GS-1101 concentrations between 0.1μM and 5μM for 3 days prior to XTT measurement. Pre-B cells showed a significant (p-value <0.0001) decrease in normalized absorbance compared to the control (without treatment) indicating a decrease in cellular viability. Finally, preliminary co-culture experiments of primary B-ALL samples and KUSA-H1 bone marrow stromal cells revealed significantly reduced B-ALL cell viability after GS-1101 treatment, signifying that GS-1101 can overcome microenviromental-mediated B-ALL cell protection; this is similar to that in other B cell malignances. In summary, these experiments demonstrate that GS-1101 inhibits growth, cell cycle progression and metabolic activity of pre-B ALL cells. Validation of these data with primary patient samples is ongoing. Disclosures:Lannutti:Gilead Sciences Inc: Employment.

Outcome of childhood relapsed or refractory mature B-cell non-Hodgkin lymphoma and acute lymphoblastic leukemia

Patients with childhood relapsed and refractory mature B-cell non-Hodgkin lymphoma (B-NHL) and acute lymphoblastic leukemia (B-ALL) are rare and have a dismal prognosis. The previous UK national analysis of 26 children over a 7-year period prior to 1996 had highlighted the poor outcome, with only three survivors. This 10-year multicenter study evaluated recent data, since 2000. Of 33 children, nine survived (27.3%), with a median follow-up of 4.3 years. On exclusion of six children treated with palliative intent, the survival was one-third (nine of 27; 33.3%). All patients with primary refractory disease (n = 7) and all except one with early relapse (n = 11) died. Administration of four doses of 375 mg/m2 of rituximab was associated with a longer survival (p = 0.006). Response to reinduction (p < 0.001) and autologous hematopoietic stem cell transplant (auto-HSCT) (p = 0.003) were significant on multivariate analysis. Patients with a time to relapse of at least 6 months are potentially curable and must be offered intensive treatment with salvage chemotherapy, rituximab and auto-HSCT.

Results of the Japan Association of Childhood Leukemia Study (JACLS) NHL-98 protocol for the treatment of B-cell non-Hodgkin lymphoma and mature B-cell acute lymphoblastic leukemia in childhood

The Japan Association of Childhood Leukemia Study (JACLS) NHL-98 is a multicenter study designed to evaluate treatment outcomes in Japanese children with B-cell non-Hodgkin lymphoma (B-NHL) and mature B-cell acute lymphoblastic leukemia (B-ALL). The study was supported by a central pathology review system and used a new, standardized protocol with short, intensive treatment regimens. From April 1998 to May 2002, 69 patients with B-NHL and B-ALL up to 16 years of age were enrolled in the NHL-98 study. Treatment was stratified by risk group; patients with limited disease were in groups A and B, and those with extensive disease were in groups C and D. Patients in groups B, C, and D received consolidation phases with high-dose methotrexate (HDMTX) followed by other multi-agent chemotherapy. Patients in group A did not receive either MTX or etoposide. Only patients in group D received etoposide. The event-free survival rates were 100% in groups A and B, 75.1% in group C, and 66.2% in group D. Overall, patients with limited disease had favorable results. For patients with extensive disease, additional treatment options such as increased doses of anticancer drugs warrant further investigation.

Outcome by Treatment Including An Intensified Consolidation Program with Dose-Escalated Doxorubicin for Newly Diagnosed Acute Lymphoblastic Leukemia (ALL): A Study by the Japan Adult Leukemia Study Group (JALSG ALL97 study).

Abstract 4334 BACKGROUDWe designed a multicenter study (JALSG ALL 97) including an intensified consolidation program with dose-escalated doxorubicin (DOX) in order to improve outcome in adults with acute lymphoblastic leukemia (ALL) in pre-imatinib era. We reported here the efficacy and prognostic factors of mainly Philadelphia chromosome (Ph)-negative patients. METHODSFrom May 1997 to December 2001, patients (age ranges 15 - 64 years) with previously untreated ALL (excluding mature B-cell ALL) were consecutively registered in this study. We modified the standard induction program with five drugs; vincristine (VCR), daunorubicin, cyclophosphamide, prednisolone (PSL) and L-asparaginase and the maintenance program with daily 6-mercaptopurine, weekly methotrexate (MTX) and monthly pulses of VCR and PSL used in CALGB 8811 study. Consolidation therapy included eight courses featuring dose-intensified DOX and intermediate-dose MTX. The total dose of DOX in consolidation phase was 330 mg/m2. For patients with Ph or t(4;11), allogeneic stem cell transplantation (HSCT) was recommended during their first complete remission (CR), if donors were available; whereas for patients without Ph or t(4;11) there was no criteria for choosing HSCT. The 5-year overall survival (OS), the 5-year disease-free survival (DFS), and the prognostic factors were evaluated. RESULTSThere were 404 eligible patients (median age, 38 years), of whom 256 were Ph-negative and 116 were Ph-positive. Of the eligible patients, 298 patients (74%) achieved CR. With a median follow-up time of 5.8 years, the estimated 5-year OS rate was 32% (95%CI: 27.1-36.9), and the 5-year DFS was 33% (95%CI: 26.8 - 38.2). The CR rates in Ph-negative and Ph-positive patients were 81% (n=208) and 56% (n=65), respectively. The 5-year OS in Ph-negative and Ph-positive patients were 39% and 15%, respectively. In Ph-negative patients, multivariate Cox analysis showed that older age, PS and WBC count were the independent prognostic factors for OS. The 5-year OS rates for patients younger than 35 years and a WBC count less than 30 × 109/L (risk group 1), for patients younger than 35 years and a WBC count above 30 × 109/L (risk group 2), for patients older than 35 years and a WBC count less than 30 × 109/L (risk group 3), and for patients older than 35 years and a WBC count above 30 × 109/L (risk group 4), were 51%, 29%, 33%, and 27%, respectively (P=0.0005). Of the 208 Ph-negative patients who achieved CR, 60 patients (29%) were underwent allogeneic-HSCT during their first CR (37 from a related donor and 23 from an unrelated donor), resulting that 8 (13%) died in remission, 16 (27%) relapsed, and 36 (60%) remained in continuous CR. The 5-year OS rate for the 60 patients was 63 %. Among them, the 5-year OS rates for the 31 patients of the risk group 1 (standard risk group) and for other 29 patients (high risk group) were 73% and 54%, respectively. Among 148 patients who did not receive allogeneic-HSCT during first CR, six (4 %) died in remission, 105 (71%) relapsed, and 37 (25%) remained in continuous CR. The 5-year OS rates for the 148 patients, for patients with standard risk, and for patients with high risk were 37%, 44% and 33%, respectively. CONCLUSIONResult of this study was in the range of those reported by most large cooperative groups, but showed little improvement of adult Ph-negative ALL therapy. The prognostic factors for long term outcome of Ph-negative patients were similar to those in previous reported. This study also suggested that allogeneic-HSCT for Ph-negative patients in first CR might have contributed to the improvement of the outcome. Disclosures:No relevant conflicts of interest to declare.

IGH and IGK gene rearrangements as PCR targets for pediatric Burkitt's lymphoma and mature B-ALL MRD analysis

We recently reported that minimal residual disease (MRD) and minimal disseminated disease (MDD), assessed by long-distance PCR (LD-PCR) for t(8;14), are negative prognostic factors in mature B-cell acute lymphoblastic leukemia (B-ALL) and in Burkitt's lymphoma (BL). However, t(8;14) is detectable in only about 70% of patients, thus preventing MRD studies by this approach in the remaining patients. At present, no molecular assays have been reported for MRD and MDD analysis in t(8;14)-negative patients. The aim of our study was to evaluate the characteristics of patient-specific immunoglobulin (Ig) gene rearrangements as RQ-PCR targets for MRD analysis, in order to extend MRD studies to those patients who are not eligible for the LD-PCR assay. The study was performed according to the guidelines of the European Study Group on MRD detection in ALL (ESG-MRD-ALL). Overall, 36 B-ALL and 19 BL cases were analyzed. Multiple PCR reactions were performed for each sample to identify heavy and kappa light-chain rearrangements. A total of 97 RQ-PCR targets (62 for B-ALL, 35 for BL) were analyzed for sensitivity. The rearrangement pattern identified was similar to that reported for normal peripheral blood lymphocytes. In 88% of the targets, a sensitivity of at least 10−4 was achieved. In 87% of patients (84% of B-ALLs, 95% of BLs) at least one sensitive target was available. All PCR targets identified at diagnosis were preserved at relapse. Our results suggest that MDD and MRD can be successfully studied using a single sensitive Ig target in the great majority of B-ALL and BL cases. The combination of LD-PCR and Ig-based assays will allow MRD analysis in virtually all of the patients.

A study of rituximab and ifosfamide, carboplatin, and etoposide chemotherapy in children with recurrent/refractory B‐cell (CD20+) non‐Hodgkin lymphoma and mature B‐cell acute lymphoblastic leukemia: A report from the Children's Oncology Group

To estimate the response rate and therapy related toxicities of the anti-CD20 monoclonal antibody rituximab when combined with chemotherapy including ifosfamide, carboplatin, and etoposide (ICE) in patients with relapsed and refractory B-cell non-Hodgkin lymphoma and mature B-cell acute lymphoblastic leukemia (B-ALL). Patients received rituximab and ICE for 1-3 cycles, depending upon response. Rituximab (375 mg/m(2)) was given on day 1 and 3 of each cycle (day 1 only for cycle 3), with ifosfamide (3,000 mg/m(2)) and etoposide (100 mg/m(2)) given on days 3, 4, and 5 and carboplatin (635 mg/m(2)) given on day 3 only. Twenty-one patients were enrolled, of whom 20 were eligible and evaluable. Although hematologic toxicities were common, only one patient was removed from study due to prolonged myelosuppression. Toxicities related to infusions of rituximab were frequent but manageable. Of the six eligible patients with diffuse large B-cell lymphoma, three achieved complete remission (CR), one had stable disease (SD), and two had progressive disease (PD). Of the 14 eligible patients with Burkitt lymphoma and B-ALL, there were four complete responses (CR), five partial responses (PR), one SD, and four with PD. Thus, the CR/PR rate for the entire group was 12/20 (60%). Following completion of protocol therapy six patients were able to proceed to consolidation with high-dose therapy and stem cell rescue. The combination of rituximab and ICE chemotherapy was associated with an encouraging objective response (OR) rate and an acceptable toxicity profile.

Progress in the treatment of adults with acute lymphoblastic leukemia

Despite improvements in the achievement of complete remission and progress in the supportive care of adults with acute lymphoblastic leukemia during the last decade, the majority of patients have eventually relapsed with overall survival in adult acute lymphoblastic leukemia of only 30-40%. However, the recent approach of adapting therapy according to biologic features appears to be resulting in significant progress for specific subsets of adults with acute lymphoblastic leukemia. The present review highlights some of these new risk-adapted approaches focusing on recent advances in treatment of Philadelphia chromosome positive acute lymphoblastic leukemia and mature B-cell acute lymphoblastic leukemia using biologically targeted therapies, and new approaches to treatment of acute lymphoblastic leukemia in older adolescents and young adults, adopting therapeutic strategies employed in the successful treatment of children with acute lymphoblastic leukemia. A recent study that examines the role of allogeneic stem cell transplant for adults with acute lymphoblastic leukemia in first remission will also be reviewed. The subset-specific approach to therapy of adult acute lymphoblastic leukemia is beginning to result in promising improvements in survival. Future improvements in survival of adults with acute lymphoblastic leukemia will depend on participation in large cooperative group trials using biologically defined protocols for this relatively rare and heterogeneous group of diseases.

A Case With Mature B-cell Acute Lymphoblastic Leukemia and Pancreatic Involvement at the Time of Diagnosis

Pancreatic infiltration with leukemic cells is a rare manifestation of acute lymphoblastic leukemia. There are only a few reported cases. We report the clinical and radiologic findings of a 4-year-old boy with mature B-cell acute lymphoblastic leukemia and pancreatic involvement. A computed tomography scan of his abdomen demonstrated diffuse hypodense lesions in the pancreas. Plasma amylase and lipase levels at that time were high, but no signs of hypoglycemia or hyperglycemia were observed. After 2 cycles of chemotherapy, the lesions in his pancreas, liver, and kidney disappeared, and his pancreatitis resolved as well. At 11 months' follow-up, after completion of therapy, the patient continues to be in remission.

Keep the Sprays Away?: Home Pesticides Linked to Childhood Cancers

Vol. 115, No. 12 EnvironewsOpen AccessKeep the Sprays Away?: Home Pesticides Linked to Childhood Cancers Tina Adler Tina Adler Search for more papers by this author Published:1 December 2007https://doi.org/10.1289/ehp.115-a594aAboutSectionsPDF ToolsDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InReddit Previous studies have suggested a link between pesticide use in the home and childhood hematopoietic tumors, the most common type of childhood cancer. A new epidemiologic study of French children diagnosed with leukemia or lymphoma in 2003 or 2004 suggests that a child has about twice the risk of developing acute leukemia (AL) or non-Hodgkin lymphoma (NHL) if his or her mother used insecticides in the home while pregnant [EHP 115:1787–1793; Rudant et al.].The researchers interviewed 1,060 children diagnosed within the prior 6 months and 1,681 control children. When analyzing the data on the children, the team controlled for other factors that may alter a child’s risk of getting cancer, including family cancer history and whether the child was breastfed. The children with cancer were part of the French National Registry of Childhood Blood Malignancies, begun in 1990, which documents all children in the country under age 15 year who have had hematopoietic tumors.The researchers asked the children’s mothers about their use while pregnant of pesticides in their homes, on pets, and in the garden. They also asked about the father’s use of pesticides while the mother was pregnant and after the child’s birth. Just over 50% of the parents who had a child with AL or NHL had used pesticides at least once during the pregnancy, as did just under 40% of the parents of the control group. Children had 2.1 and 1.8 times the risk of developing AL or NHL, respectively, with maternal use of pesticides during pregnancy.Mothers’ use of insecticides during pregnancy was significantly associated with childhood AL, NHL, and mixed-cell Hodgkin lymphomas (HLs). Use of pesticides by fathers was also related to AL and NHL. The association was stronger for common B-cell acute lymphoblastic leukemia (ALL) and acute myeloblastic leukemia than for T-cell ALL or mature B-cell ALL. It was also stronger for Burkitt lymphoma than for the other NHLs. Of the HLs, the study linked only the mixed-cell subtype to pesticide use. The strength of the association between pesticide use in the home and cancer did not change as the children grew older.This is the first study to tease out the different types of hematopoietic cancers as they relate to pesticide use in the home. Other studies have found a link between parents’ occupational exposure to pesticides and childhood cancers, but few of the parents in the French study were exposed to pesticides at work or through farming. Whether a family was rural or urban didn’t alter a child’s risk of developing cancer.The two types of lymphoma associated with maternal pesticide use during pregnancy have also both been linked to the Epstein-Barr virus, which may suggest a link between pesticide exposure and susceptibility to a viral lymphoma. According to the authors, the consistency of the findings suggests pregnant women may want to avoid pesticide use.FiguresReferencesRelatedDetails Vol. 115, No. 12 December 2007Metrics About Article Metrics Publication History Originally published1 December 2007Published in print1 December 2007 Financial disclosuresPDF download License information EHP is an open-access journal published with support from the National Institute of Environmental Health Sciences, National Institutes of Health. All content is public domain unless otherwise noted. Note to readers with disabilities EHP strives to ensure that all journal content is accessible to all readers. However, some figures and Supplemental Material published in EHP articles may not conform to 508 standards due to the complexity of the information being presented. If you need assistance accessing journal content, please contact [email protected]. Our staff will work with you to assess and meet your accessibility needs within 3 working days.

Prognostic Role of Minimal Residual Disease in Mature B-Cell Acute Lymphoblastic Leukemia of Childhood

To study the prevalence of t(8;14) at diagnosis and the response kinetics to treatment of minimal residual disease (MRD) in B-cell acute lymphoblastic leukemia (B-ALL) patients and determine its impact on prognosis. A total of 68 children affected by de novo B-ALL enrolled onto the Berlin-Frankfurt-Muenster-based Italian Association of Pediatric Hematology and Oncology LNH-97 clinical protocol were studied. Bone marrow aspirate from each patient was analyzed for the presence of t(8;14)(q24;q32) by long-distance polymerase chain reaction at diagnosis, after the first chemotherapy cycle, and after subsequent cycles until negative for MRD. Morphologic and immunophenotypic analyses were reviewed centrally. A total of 47 patients (69%) were positive for t(8;14)(q24;q32). MRD response kinetics was determined in 39 patients. All of them reached clinical complete remission and most (31 of 39) became MRD negative after the first chemotherapy cycle. The 3-year relapse-free survival (RFS) was 38% (SE = 17%) in patients MRD positive after the first chemotherapy cycle compared with 84% (SE = 7%) in MRD-negative patients (P = .0005), whereas there was no difference in RFS for children who reached a clinical complete remission after the first chemotherapy cycle versus those who did not (RFS = 72% and SE = 9%; RFS = 79% and SE = 11%, respectively; P = .8). In multivariate analysis, MRD was shown to be predictive of higher risk of failure. Our study demonstrated that MRD carries a negative prognostic impact in B-ALL patients and suggests that a better risk-adapted therapy, possibly including the use of anti-CD20 monoclonal antibody, should be considered in selected patients.