Clinical trial recruitment of people who speak languages other than english: a children's oncology group report.

BACKGROUND: Persons who speak languages other than English (LOE) are underrepresented in clinical trials; this may be due in part to inadequate multilevel resources. We conducted a survey of institutions affiliated with the Children's Oncology Group (COG) to characterize current research recruitment practices and resources regarding translation and interpretation services. METHODS: In October 2022, a 20-item survey was distributed electronically to institutions affiliated with COG to assess consent practices and resources for recruiting participants who speak LOE to COG trials. Descriptive statistics were used to summarize responses; responses were compared by institution size, type, and respondent role. RESULTS: The survey was sent to a total of 230 institutions, and the response rate was 60% (n = 139). In total, 60% (n = 83) had access to short form consents. Full consent form translation was required at 50% of institutions, and 12% of Institutional Review Boards restricted use of centrally translated consent forms. Forty-six percent of institutions reported insufficient funding to support translation costs; 15% had access to no-cost translation services. Forty-four percent (n = 61) were required to use in-person interpreters for consent discussions; the most cited barrier to obtaining consent was lack of available in-person interpreters (56%). Forty-six percent (n = 69) reported that recruiting persons who speak LOE to clinical trials was somewhat or very difficult. CONCLUSIONS: Institutions affiliated with COG face resource-specific challenges that impede recruitment of participants who speak LOE in clinical trials. These findings indicate an urgent need to identify strategies aimed at reducing recruitment barriers to ensure equitable access to clinical trials.

Comparison of the Transcriptomic Signatures in Pediatric and Adult CML.

Children with chronic myeloid leukemia (CML) tend to present with higher white blood counts and larger spleens than adults with CML, suggesting that the biology of pediatric and adult CML may differ. To investigate whether pediatric and adult CML have unique molecular characteristics, we studied the transcriptomic signature of pediatric and adult CML CD34+ cells and healthy pediatric and adult CD34+ control cells. Using high-throughput RNA sequencing, we found 567 genes (207 up- and 360 downregulated) differentially expressed in pediatric CML CD34+ cells compared to pediatric healthy CD34+ cells. Directly comparing pediatric and adult CML CD34+ cells, 398 genes (258 up- and 140 downregulated), including many in the Rho pathway, were differentially expressed in pediatric CML CD34+ cells. Using RT-qPCR to verify differentially expressed genes, VAV2 and ARHGAP27 were significantly upregulated in adult CML CD34+ cells compared to pediatric CML CD34+ cells. NCF1, CYBB, and S100A8 were upregulated in adult CML CD34+ cells but not in pediatric CML CD34+ cells, compared to healthy controls. In contrast, DLC1 was significantly upregulated in pediatric CML CD34+ cells but not in adult CML CD34+ cells, compared to healthy controls. These results demonstrate unique molecular characteristics of pediatric CML, such as dysregulation of the Rho pathway, which may contribute to clinical differences between pediatric and adult patients.

A phase I study of panobinostat in children with relapsed and refractory hematologic malignancies.

Background: Panobinostat demonstrates activity against pediatric cancers in vitro. A phase I trial in children with refractory hematologic malignancies was conducted. Study design: The trial evaluated two schedules of oral panobinostat using 3 + 3 dose escalations in 28-day cycles. For children with leukemia, panobinostat was given once daily three days a week each week at 24, 30 and 34 mg/m2/day. For children with lymphoma, panobinostat was given once daily three days a week every other week at 16, 20 and 24 mg/m2/day. Cerebrospinal fluid (CSF) from Day 29 of the first cycle, when available, was evaluated for PK. The study was registered on clinicaltrials.gov (NCT01321346) Results: Twenty-two subjects enrolled with leukemia. Five enrolled at dose level 1, 6 at dose level 2, and 11 at dose level 3. There was one dose limiting toxicity (DLT) in the leukemia arm at dose level 3 (Grade 4 hypertriglyceridemia), but no maximum tolerated dose (MTD) was identified. No subjects required removal from protocol therapy for QTc prolongation. PK studies were available in 11 subjects with similar exposure in children as in adults. Four Day 29 CSF specimens were found to have panobinostat levels below the lower limit of quantification. Five subjects with lymphoma were enrolled and received study drug, and 4 were evaluable for DLT. A DLT was reported (Grade 3 enteritis) on the lymphoma arm. Conclusions: Panobinostat was tolerated in heavily pretreated pediatric subjects. Gastrointestinal effects were observed on this study. There were no cardiac findings. There were no responses.

BMI1 enhancer polymorphism underlies chromosome 10p12.31 association with childhood acute lymphoblastic leukemia.

Genome-wide association studies of childhood acute lymphoblastic leukemia (ALL) have identified regions of association at PIP4K2A and upstream of BMI1 at chromosome 10p12.31-12.2. The contribution of both loci to ALL risk and underlying functional variants remain to be elucidated. We carried out single nucleotide polymorphism (SNP) imputation across chromosome 10p12.31-12.2 in Latino and non-Latino white ALL cases and controls from two independent California childhood leukemia studies, and additional Genetic Epidemiology Research on Aging study controls. Ethnicity-stratified association analyses were performed using logistic regression, with meta-analysis including 3,133 cases (1,949 Latino, 1,184 non-Latino white) and 12,135 controls (8,584 Latino, 3,551 non-Latino white). SNP associations were identified at both BMI1 and PIP4K2A. After adjusting for the lead PIP4K2A SNP, genome-wide significant associations remained at BMI1, and vice-versa (pmeta < 10-10 ), supporting independent effects. Lead SNPs differed by ethnicity at both peaks. We sought functional variants in tight linkage disequilibrium with both the lead Latino SNP among Admixed Americans and lead non-Latino white SNP among Europeans. This pinpointed rs11591377 (pmeta = 2.1 x 10-10 ) upstream of BMI1, residing within a hematopoietic stem cell enhancer of BMI1, and which showed significant preferential binding of the risk allele to MYBL2 (p = 1.73 x 10-5 ) and p300 (p = 1.55 x 10-3 ) transcription factors using binomial tests on ChIP-Seq data from a SNP heterozygote. At PIP4K2A, we identified rs4748812 (pmeta = 1.3 x 10-15 ), which alters a RUNX1 binding motif and demonstrated chromosomal looping to the PIP4K2A promoter. Fine-mapping chromosome 10p12 in a multi-ethnic ALL GWAS confirmed independent associations and identified putative functional variants upstream of BMI1 and at PIP4K2A.

Arsenic Trioxide Consolidation Allows Anthracycline Dose Reduction for Pediatric Patients With Acute Promyelocytic Leukemia: Report From the Children's Oncology Group Phase III Historically Controlled Trial AAML0631.

Purpose The Children's Oncology Group AAML0631 trial for newly diagnosed pediatric acute promyelocytic leukemia (APL) was a phase III historically controlled trial to determine the survival of patients receiving arsenic trioxide (ATO) consolidation and reduced doses of anthracyclines. Patients and Methods Patients age 2 to 21 years with de novo APL confirmed by PML-RARα polymerase chain reaction were stratified as standard risk (SR) or high risk (HR) on the basis of diagnostic WBC count. All patients received all-trans retinoic acid (ATRA) during induction, each consolidation course, and maintenance. All patients received two cycles of ATO therapy during consolidation 1, an additional two (SR) or three (HR) consolidation courses that included high-dose cytarabine and anthracycline, and maintenance therapy comprising ATRA, oral methotrexate, and mercaptopurine. Results One hundred one patients (66 SR and 35 HR) were evaluable for outcome. The 3-year overall survival was 94%, and event-free survival (EFS) was 91%. For SR and HR patients with APL, the overall survival was 98% versus 86% ( P = .003), and EFS was 95% versus 83% ( P = .03), respectively. The EFS for SR patients in AAML0631 was noninferior to that of patients in the AIDA 0493 historical control, which used a significantly higher anthracycline dose and did not include ATO consolidation. Relapse risk for patients in AAML0631 from end consolidation 1 (after ATO treatment) was only 4% at 3 years and did not differ significantly between SR and HR patients. Conclusion ATO consolidation cycles were well tolerated in pediatric patients with APL and allowed significant reduction in cumulative anthracycline doses while maintaining excellent survival and a low relapse risk for both SR and HR patients with APL.

Maternal diet quality before pregnancy and risk of childhood leukaemia.

Previous studies on maternal nutrition and childhood leukaemia risk have focused on the role of specific nutrients such as folate and have not considered broader measures of diet quality, which may better capture intake of diverse nutrients known to impact fetal development. We examined the relationship between maternal diet quality before pregnancy, as summarised by a diet quality index, and risk of childhood acute lymphoblastic leukaemia (ALL) and acute myeloid leukaemia (AML) in a case-control study in California. Dietary intake in the year before pregnancy was assessed using FFQ in 681 ALL cases, 103 AML cases and 1076 matched controls. Conditional logistic regression was used to estimate OR and 95 % CI for diet quality continuous score and quartiles (Q1-Q4). Higher maternal diet quality score was associated with reduced risk of ALL (OR 0·66; 95 % CI 0·47, 0·93 for Q4 v. Q1) and possibly AML (OR 0·42; 95 % CI 0·15, 1·15 for Q4 v. Q1). No single index component appeared to account for the association. The association of maternal diet quality with risk of ALL was stronger in children diagnosed under the age of 5 years and in children of women who did not report using vitamin supplements before pregnancy. These findings suggest that the joint effects of many dietary components may be important in influencing childhood leukaemia risk.

Congenital B-lymphoblastic leukemia with a cryptic MLL rearrangement and post-treatment evolution to mixed phenotype acute leukemia.

Congenital leukemia is a rare event with a poor prognosis. We report a case of congenital leukemia with a cryptic rearrangement of MLL demonstrable only with RT-PCR. Interestingly, with treatment, the patient showed lineage plasticity of the leukemia with the development of monocytic lineage blasts after presenting with B-cell lineage blasts. This was heralded by the development of a new clonal cytogenetic abnormality. This case highlights the primitive nature of the leukemic cells in congenital leukemia, and emphasizes that RT-PCR for MLL rearrangements may identify a subset of cases which are otherwise negative by karyotyping, FISH, and chromosomal microarrays.

Bortezomib, Dexamethasone, Mitoxantrone, and Vinorelbine (BDMV): An Active Reinduction Regimen for Children With Relapsed Acute Lymphoblastic Leukemia and Asparaginase Intolerance.

BACKGROUND: Children with relapsed acute lymphoblastic leukemia (ALL) typically receive vincristine-prednisone-L-asparaginase-doxorubicin reinduction chemotherapy similar to contemporary induction regimens. However, up to 20% of patients are unable to receive vincristine-prednisone-L-asparaginase-doxorubicin secondary to asparaginase intolerance. We report our experience with a promising reinduction regimen for children with relapsed ALL who are unable to receive asparaginase. PATIENTS AND METHODS: This is a single institution, retrospective review of the safety and activity of bortezomib, dexamethasone, mitoxantrone, and vinorelbine (BDMV) in patients with relapsed ALL. Complete remission and adverse events after reinduction were study endpoints. Patients treated with BDMV between 2012 and 2015 were identified. Response and adverse events (AEs) were assessed by review of medical records. Standard response criteria were used and AEs were graded based on NCI CTCAEv4.0. RESULTS: Seven of 10 patients achieved complete remission after 1 cycle of BDMV, with 4 achieving minimal residual disease negativity. The most common ≥grade 3 nonhematological toxicities were infection (91%), gastrointestinal (45%), metabolic (45%), and cardiovascular (9%). CONCLUSIONS: BDMV is an active reinduction regimen for children with relapsed ALL who cannot receive asparaginase. The toxicity profile is as expected for this patient population. Further prospective clinical trials are warranted to evaluate the safety and efficacy of BDMV.

A Heritable Missense Polymorphism in CDKN2A Confers Strong Risk of Childhood Acute Lymphoblastic Leukemia and Is Preferentially Selected during Clonal Evolution.

Genome-wide association studies (GWAS) have identified SNPs in six genes that are associated with childhood acute lymphoblastic leukemia (ALL). A lead SNP was found to occur on chromosome 9p21.3, a region that is deleted in 30% of childhood ALLs, suggesting the presence of causal polymorphisms linked to ALL risk. We used SNP genotyping and imputation-based fine-mapping of a multiethnic ALL case-control population (Ncases = 1,464, Ncontrols = 3,279) to identify variants of large effect within 9p21.3. We identified a CDKN2A missense variant (rs3731249) with 2% allele frequency in controls that confers three-fold increased risk of ALL in children of European ancestry (OR, 2.99; P = 1.51 × 10(-9)) and Hispanic children (OR, 2.77; P = 3.78 × 10(-4)). Moreover, of 17 patients whose tumors displayed allelic imbalance at CDKN2A, 14 preferentially retained the risk allele and lost the protective allele (PBinomial = 0.006), suggesting that the risk allele provides a selective advantage during tumor growth. Notably, the CDKN2A variant was not significantly associated with melanoma, glioblastoma, or pancreatic cancer risk, implying that this polymorphism specifically confers ALL risk but not general cancer risk. Taken together, our findings demonstrate that coding polymorphisms of large effect can underlie GWAS "hits" and that inherited polymorphisms may undergo directional selection during clonal expansion of tumors.

Clinical and microbiologic outcomes of quinolone prophylaxis in children with acute myeloid leukemia.

BACKGROUND: Intensifying treatment for pediatric acute myeloid leukemia (AML) has improved survival, with infections now being a leading cause of morbidity. Because quinolone prophylaxis is effective in adults with AML and in transplant populations, ciprofloxacin prophylaxis (CPx) was introduced as the standard for pediatric AML. We report here the impact of CPx in this population. METHODS: Prevalence of fever and neutropenia, frequency and pathogen spectrum of infections, antibiotic use, supportive care and mortality before and after implementation of CPx were retrospectively compared in children with AML. RESULTS: The cohort included 35 patients with de novo and 10 with relapsed AML, who together underwent 153 chemotherapy courses. Fever and neutropenia resulting in the use of empiric antibiotics occurred in 90% of chemotherapy courses (137/153); this was associated with proven bacteremia in 26%. The use of CPx did not change the incidence of febrile or infectious episodes, number of days of fever or antibiotic treatment or mortality. CPx was associated with a significant decrease in infections caused by Gram-negative rods (13.4% vs 4.7%) but a concomitant significant increase in bacteremia caused by viridans streptococci (12% vs 28%), resulting in no significant overall difference in the incidence of bacteremia between the 2 groups (35.9% vs 31.5%). CONCLUSIONS: CPx neither alter the incidence of overall bacteremia nor change the pattern of fever or use of supportive care. Our experience supports further investigation into the use of extended-spectrum quinolone prophylaxis during therapy for pediatric AML.

Association of genetic variation in IKZF1, ARID5B, and CEBPE and surrogates for early-life infections with the risk of acute lymphoblastic leukemia in Hispanic children.

BACKGROUND: Genome-wide association studies focusing on European-ancestry populations have identified ALL risk loci on IKZF1, ARID5B, and CEBPE. To capture the impacts of these genes on ALL risk in the California Hispanic population, we comprehensively assessed the variation within the genes and further assessed the joint effects between the genetic variation and surrogates for early-life infections (the presence of older siblings, daycare attendance, and ear infections). METHODS: Genotypic data for 323 Hispanic ALL cases and 454 controls from the California Childhood Leukemia Study were generated using Illumina OmniExpress v1 platform. Logistic regression assuming a log-additive model estimated odds ratios (OR) associated with each SNP, adjusted for age, sex, and the first five principal components. In addition, we examined potential interactions between six ALL risk alleles and surrogates for early-life infections using logistic regression models that included an interaction term. RESULTS: Significant associations between genotypes at IKZF1, ARID5B, and CEBPE and ALL risk were identified: rs7780012, OR 0.50, 95% confidence interval (CI) 0.35-0.71 (p = 0.004); rs7089424, OR 2.12, 95% CI 1.70-2.65 (p = 1.16 × 10(-9)); rs4982731, OR 1.69, 95% CI 1.37-2.08 (p = 2.35 × 10(-6)), respectively. Evidence for multiplicative interactions between genetic variants and surrogates for early-life infections with ALL risk was not observed. CONCLUSIONS: Consistent with findings in non-Hispanic White population, our study showed that variants within IKZF1, ARID5B, and CEBPE were associated with increased ALL risk, and the effects for ARID5B and CEBPE were most prominent in the high-hyperdiploid ALL subtype in the California Hispanic population. Results implicate the ARID5B, CEBPE, and IKZF1 genes in the pathogenesis of childhood ALL.

Obesity is associated with residual leukemia following induction therapy for childhood B-precursor acute lymphoblastic leukemia.

Obesity is associated with poorer event-free survival (EFS) in pediatric acute lymphoblastic leukemia (ALL). Persistent minimal residual disease (MRD) in the bone marrow as measured by multidimensional flow cytometry (MDF) is a key early prognostic indicator and is strongly associated with EFS. We therefore hypothesized that obesity during induction would be associated with positive end-of-induction MRD (≥0.01%). We analyzed MDF of end-induction bone marrow samples from a historical cohort of 198 children newly diagnosed with B-precursor ALL (BP-ALL) and treated with Children's Oncology Group induction regimens. We assessed the influence of body mass index on risk for positive end-induction MRD in the bone marrow. In our cohort of BP-ALL, 30 children (15.2%) were overweight and 41 (20.7%) were obese at diagnosis. Independent of established predictors of treatment response, obesity during induction was associated with significantly greater risk for persistent MRD (odds ratio, 2.57; 95% confidence interval, 1.19 to 5.54; P = .016). Obesity and overweight were associated with poorer EFS irrespective of end-induction MRD (P = .012). Obese children with newly diagnosed BP-ALL are at increased risk for positive end-induction MRD and poorer EFS.

Tobacco smoke exposure and the risk of childhood acute lymphoblastic and myeloid leukemias by cytogenetic subtype.

BACKGROUND: Tobacco smoke contains carcinogens known to damage somatic and germ cells. We investigated the effect of tobacco smoke on the risk of childhood acute lymphoblastic leukemia (ALL) and myeloid leukemia (AML), especially subtypes of prenatal origin such as ALL with translocation t(12;21) or high-hyperdiploidy (51-67 chromosomes). METHODS: We collected information on exposures to tobacco smoking before conception, during pregnancy, and after birth in 767 ALL cases, 135 AML cases, and 1,139 controls (1996-2008). Among cases, chromosome translocations, deletions, or aneuploidy were identified by conventional karyotype and fluorescence in situ hybridization. RESULTS: Multivariable regression analyses for ALL and AML overall showed no definite evidence of associations with self-reported (yes/no) parental prenatal active smoking and child's passive smoking. However, children with history of paternal prenatal smoking combined with postnatal passive smoking had a 1.5-fold increased risk of ALL [95% confidence interval (CI), 1.01-2.23], compared to those without smoking history (ORs for pre- or postnatal smoking only were close to one). This joint effect was seen for B-cell precursor ALL with t(12;21) (OR = 2.08; 95% CI, 1.04-4.16), but not high hyperdiploid B-cell ALL. Similarly, child's passive smoking was associated with an elevated risk of AML with chromosome structural changes (OR = 2.76; 95% CI, 1.01-7.58), but not aneuploidy. CONCLUSIONS: Our data suggest that exposure to tobacco smoking was associated with increased risks of childhood ALL and AML; and risks varied by timing of exposure (before and/or after birth) and cytogenetic subtype, based on imprecise estimates. IMPACT: Parents should limit exposures to tobacco smoke before and after the child's birth.

Inverse association between brown adipose tissue activation and white adipose tissue accumulation in successfully treated pediatric malignancy.

BACKGROUND: Although the accumulation of white adipose tissue (WAT) is a risk factor for disease, brown adipose tissue (BAT) has been suggested to have a protective role against obesity. OBJECTIVE: We studied whether changes in BAT were related to changes in the amounts of subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) in children treated for malignancy. DESIGN: We examined the effect of BAT activity on weight, SAT, and VAT in 32 pediatric patients with cancer whose positron emission tomography-computed tomography (PET-CT) scans at diagnosis showed no BAT activity. Changes in weight, SAT, and VAT from diagnosis to remission for children with metabolically active BAT at disease-free follow-up (BAT+) were compared with those in children without visualized BAT when free of disease (BAT-). RESULTS: Follow-up PET-CT studies (4.7 ± 2.4 mo later) after successful treatment of the cancer showed BAT+ in 19 patients but no active BAT (BAT-) in 13 patients. BAT+ patients, in comparison with BAT- patients, gained significantly less weight (3.3 ± 6.6% compared with 11.0 ± 11.6%; P = 0.02) and had significantly less SAT (18.2 ± 26.5% compared with 67.4 ± 71.7%; P = 0.01) and VAT (22.6 ± 33.5% compared with 131.6 ± 171.8%; P = 0.01) during treatment. Multiple regression analysis indicated that the inverse relations between BAT activation and measures of weight, SAT, and VAT persisted even after age, glucocorticoid treatment, and the season when the PET-CT scans were obtained were accounted for. CONCLUSION: The activation of BAT in pediatric patients undergoing treatment of malignancy is associated with significantly less adipose accumulation. This trial was registered at clinicaltrials.gov as NCT01517581.

Higher dose imatinib for children with de novo chronic phase chronic myelogenous leukemia: a report from the Children's Oncology Group.

PURPOSE: To determine the efficacy of imatinib in children with newly diagnosed chronic phase (CP) chronic myelogenous leukemia (CML). METHODS: This was an open label, multi-center phase II clinical trial. Courses were defined as consecutive 28-day intervals. Oral imatinib was administered daily at 340 mg/m² without interruption in the absence of toxicity. RESULTS: Fifty-one children received 978 28-day courses of imatinib. The most common toxicities encountered were hematologic. Forty-one patients (80%) achieved a complete hematologic response by the end of course 2. Nineteen children (38%) obtained a complete cytogenetic response (CCyR) at the end of course 3. Overall, 72% achieved CCyR at a median time of 5.6 months. The rate of complete molecular response (>3 log reduction) was 27%. Progression-free and overall survival at 3 years were 72% ± 6.4% and 92% ± 3.9%, respectively. CONCLUSIONS: Daily oral imatinib at a dose of 340 mg/m² is well tolerated in children. In addition, imatinib therapy is effective in inducing a high percent of hematologic, cytogenetic and molecular responses, comparable to adults with CML. (This study was registered at ClinicalTrials.gov under identifier NCT00030394.).

B-acute lymphoblastic leukemia and cystinuria in a patient with duplication 22q11.21 detected by chromosomal microarray analysis.

Duplication 22q11.2 syndrome is the result of a microduplication of the same chromosomal region that is deleted in DiGeorge and Velocardiofacial syndromes. We describe a patient with dysmorphic features who was diagnosed with pre-B acute lymphoblastic leukemia, and developed cystinuria and pancreatitis during treatment. Duplication 22q11.2 has not been previously described in association with hematologic abnormalities. Chromosomal microarray technology was used to diagnose duplication 22q11.2 syndrome. In this era of advanced genomics, this technology has become an important method for helping to determine the molecular basis of diseases, best treatments and ultimately patient outcomes.

Graft-versus-leukemia effect on infant lymphoblastic leukemia relapsed after sibling hematopoietic stem cell transplantation.

INTRODUCTION: Infant acute lymphoblastic leukemia (ALL) is considered a high-risk entity. Patients diagnosed in the first 3 months of life have especially high mortality. By morphology, infant ALL is classified as a lymphoid lineage leukemia; however, its physiologic behavior has brought many to consider it a pathologic hybrid between lymphoid leukemia and myeloid leukemias. As such, standard of care currently employs the use of chemotherapeutic agents used commonly in ALL protocols and agents typically reserved for the treatment of myelogenous lineage leukemias. The role of hematopoietic stem cell transplantation and graft-versus-leukemia effect in these patients has not been well studied. CASE PRESENTATION: An earlier healthy 9-week-old Hispanic male diagnosed with precursor B-cell lymphoblastic leukemia was treated with protocol P9407 and matched sibling hematopoietic stem cell transplantation. Relapse was noted on posttransplant day +114 with blasts on peripheral blood smear. The sole antigraft-versus-host disease (GVHD) agent, cyclosporine, was discontinued. Blast clearance from the peripheral blood was obtained by posttransplant day +128 with the appearance of skin and liver GVHD at posttransplant day +181. Bone marrow examination on posttransplant day +205 revealed normal marrow with no evidence of leukemic cells. He remains disease free more than 2 years posttransplant. CONCLUSION: Traditionally, graft-versus-leukemia effect was thought to contribute therapeutically little to the treatment of ALL by hematopoietic stem cell transplantation (HSCT). The effects of graft-versus-leukemia immunologic phenomenon in our patient with infant acute lymphoblastic leukemia underscore the potential that infant ALL may not be entirely the same biologic entity as standard pediatric ALL and may be more responsive than understood earlier. Therapeutic response and appearance of GVHD after the withdrawal of immunosuppression in this patient provides evidence that graft-versus-leukemia effect may play a role in disease control in infant ALL after HSCT. Patients who relapse after the HSCT may be salvaged with the withdrawal of immunosuppression. This suggests that other immunotherapeutic interventions in the context of relapse may offer potential clinical benefit in this disease.

The aggresome pathway as a target for therapy in hematologic malignancies.

Misfolded or unfolded proteins are often refolded with the help of chaperones or degraded by the 26S proteasome. An alternative fate of these proteins is the aggresome pathway. The microtubule-organizing center (MTOC) transports unfolded proteins to lysosomes and are degraded through autophagy. Histone deacetylase 6 (HDAC6) deacetylates alpha-tubulin, which is thought to be a component of the MTOC. Recently, two small molecule inhibitors of the aggresome pathway and HDAC6 have been described. One inhibitor, tubacin, prevents deacetylation of alpha-tubulin and produces accumulation of polyubiquitinated proteins and apoptosis. Tubacin acts synergistically with the proteasome inhibitor, bortezomib, to induce cytotoxicity in one type of hematologic malignancy, multiple myeloma. The other, LBH589, is a pan HDAC inhibitor and hydroxamic acid derivative that induces apoptosis of multiple myeloma cells resistant to conventional therapies. In this review, we summarize recent reports on targeting the aggresome pathway and HDAC6 in hematologic malignancies.

Role of the aggresome pathway in cancer: targeting histone deacetylase 6-dependent protein degradation.

Misfolded or aggregated proteins have two fates: they are either refolded with the help of chaperones or degraded by the proteasome. Cells also have an alternative pathway that involves intracellular "storage bins" for misfolded intracellular proteins known as aggresomes. Aggresomes recruit motor proteins that transport misfolded or aggregated proteins to chaperones and proteasomes for subsequent destruction. There is emerging evidence that inhibiting the aggresome pathway leads to accumulation of misfolded proteins and apoptosis in tumor cells through autophagy. We discuss the role of aggresomes in cancer and the potential to target this pathway for therapy.

Phase 2 study of docetaxel in the treatment of childhood refractory acute leukemias: a Children's Oncology Group report.

BACKGROUND: To determine the response rate and toxicity of docetaxel when administered as a 60 mg/m(2) dose by 1 hr intravenous (IV) infusion weekly x 3 weeks in children with relapsed acute lymphoblastic leukemia (ALL) or acute myeloid leukemia (AML). PROCEDURE: Patients who were under the age of 22-year-old at the time of the original ALL or AML diagnosis and in a second relapse were accrued from August 2002 to May 2005 for this Children's Oncology Group (COG) phase 2 study (ADVL0023). Ten patients with ALL and two patients with AML were enrolled. RESULTS: There were no complete or partial responses observed. The most common grade 3 or 4 toxicities were hematologic followed by febrile neutropenia. One patient developed a dose limiting elevation in serum bilirubin, but no other significant hepatotoxicity was observed. CONCLUSIONS: Docetaxel was not effective therapy for children with relapsed ALL at the dose and schedule tested.