Drug interactions may be important risk factors for methotrexate neurotoxicity, particularly in pediatric leukemia patients

Purpose: Methotrexate administration is associated with frequent adverse neurological events during treatment for childhood acute lymphoblastic leukemia. Here, we present evidence to support the role of common drug interactions and low vitamin B12 levels in potentiating methotrexate neurotoxicity. Methods: We review the published evidence and highlight key potential drug interactions as well as present clinical evidence of severe methotrexate neurotoxicity in conjunction with nitrous oxide anesthesia and measurements of vitamin B12 levels among pediatric leukemia patients during therapy. Results: We describe a very plausible mechanism for methotrexate neurotoxicity in pediatric leukemia patients involving reduction in methionine and consequential disruption of myelin production. We provide evidence that a number of commonly prescribed drugs in pediatric leukemia management interact with the same folate biosynthetic pathways and/or reduce functional vitamin B12 levels and hence are likely to increase the toxicity of methotrexate in these patients. We also present a brief case study supporting out hypothesis that nitrous oxide contributes to methotrexate neurotoxicity and a nutritional study, showing that patients. Conclusions: Use of nitrous oxide in pediatric leukemia patients at the same time as methotrexate use should be avoided especially as many suitable alternative anesthetic agents exist. Clinicians should consider monitoring levels of vitamin B12 in patients suspected of having methotrexate- induced neurotoxic effects

Overcoming steroid resistance in T cell acute lymphoblastic leukemia

In a Perspective, Pieter Van Vlierberghe and Steven Goossens discuss Meijerink and colleagues' findings on steroid resistance in pediatric T cell acute lymphoblastic leukemia

How to target apoptosis signaling pathways for the treatment of pediatric cancers

Apoptosis represents one of the most important forms of cell death in higher organisms and is typically dysregulated in human cancers, including pediatric tumors. This implies that ineffective engagement of cell death programs can contribute to tumor formation as well as tumor progression. In addition, the majority of cytotoxic therapeutic principles rely on the activation of cell death signaling pathways in cancer cells. Blockade of signaling networks that lead to cell death can therefore confer treatment resistance. A variety of genetic and epigenetic events as well as dysfunctional regulation of signaling networks have been identified as underlying causes of cell death resistance in childhood malignancies. Apoptosis pathways can be therapeutically exploited by enhancing proapoptotic signals or by neutralizing antiapoptotic programs. The challenge in the coming years will be to successfully transfer this knowledge into the development of innovative treatment approaches for children with cancer

Assessing Feasibility and Effectiveness of Pediatric Dental Provider’s Role in Oral Health and Prevention Education in the Care of Children with Leukemia

Purpose: Pediatric dentists could serve a role in care of children with leukemia. Oral sequelae of cancer therapies are well documented. The purpose of this study is to assess the feasibility and effectiveness of the pediatric dentist in the care of patients with leukemia. Methods: Pediatric Hematology and Oncology at Virginia Commonwealth University was educated on the proposed protocol and administered a questionnaire to assess feasibility of implementing prevention education by the pediatric dentist. Patients were randomized into two groups at diagnosis: one receiving current oral health protocol and those receiving one-on-one prevention education with the pediatric dentist at three points during treatment. Data was collected through clinical intraoral examination and salivary sample. Results: All respondents reported this would address a known problem for patients. They agreed it is feasible and would be a valuable addition to care of these patients. Subject recruitment is ongoing for the effectiveness portion of the study. Conclusion: The addition of the pediatric dentist to the pediatric oncology care team is warranted and feasible

The molecular basis of T cell acute lymphoblastic leukemia

T cell acute lymphoblastic leukemias (T-ALLs) arise from the malignant transformation of hematopoietic progenitors primed toward T cell development, as result of a multistep oncogenic process involving constitutive activation of NOTCH signaling and genetic alterations in transcription factors, signaling oncogenes, and tumor suppressors. Notably, these genetic alterations define distinct molecular groups of T-ALL with specific gene expression signatures and clinicobiological features. This review summarizes recent advances in our understanding of the molecular genetics of T-ALL

GRFS and CRFS in alternative donor hematopoietic cell transplantation for pediatric patients with acute leukemia.

We report graft-versus-host disease (GVHD)-free relapse-free survival (GRFS) (a composite end point of survival without grade III-IV acute GVHD [aGVHD], systemic therapy-requiring chronic GVHD [cGVHD], or relapse) and cGVHD-free relapse-free survival (CRFS) among pediatric patients with acute leukemia (n = 1613) who underwent transplantation with 1 antigen-mismatched (7/8) bone marrow (BM; n = 172) or umbilical cord blood (UCB; n = 1441). Multivariate analysis was performed using Cox proportional hazards models. To account for multiple testing, P \u3c .01 for the donor/graft variable was considered statistically significant. Clinical characteristics were similar between UCB and 7/8 BM recipients, because most had acute lymphoblastic leukemia (62%), 64% received total body irradiation-based conditioning, and 60% received anti-thymocyte globulin or alemtuzumab. Methotrexate-based GVHD prophylaxis was more common with 7/8 BM (79%) than with UCB (15%), in which mycophenolate mofetil was commonly used. The univariate estimates of GRFS and CRFS were 22% (95% confidence interval [CI], 16-29) and 27% (95% CI, 20-34), respectively, with 7/8 BM and 33% (95% CI, 31-36) and 38% (95% CI, 35-40), respectively, with UCB (P \u3c .001). In multivariate analysis, 7/8 BM vs UCB had similar GRFS (hazard ratio [HR], 1.12; 95% CI, 0.87-1.45; P = .39), CRFS (HR, 1.06; 95% CI, 0.82-1.38; P = .66), overall survival (HR, 1.07; 95% CI, 0.80-1.44; P = .66), and relapse (HR, 1.44; 95% CI, 1.03-2.02; P = .03). However, the 7/8 BM group had a significantly higher risk for grade III-IV aGVHD (HR, 1.70; 95% CI, 1.16-2.48; P = .006) compared with the UCB group. UCB and 7/8 BM groups had similar outcomes, as measured by GRFS and CRFS. However, given the higher risk for grade III-IV aGVHD, UCB might be preferred for patients lacking matched donors. © 2019 American Society of Hematology. All rights reserved

Treatment of Adult Patients with Relapsed/Refractory B-Cell Philadelphia-Negative Acute Lymphoblastic Leukemia

The majority of adult patients affected by B-cell acute lymphoblastic leukemia (B-ALL) will relapse after an initial response, while approximately 20% will display primary resistant disease. Patients suffering from relapsed/refractory B-ALL have a very poor outcome. Allogeneic hematopoietic cell transplantation (HCT) still represents the only curative approach, but is not so frequently feasible, because of patient’s fitness, donor availability, and the ability to achieve a remission prior to HCT. The estimated remission rates with conventional cytotoxic agents are around 30%, but they are short-lived. These disappointing results led to the introduction of new immunologic-based treatments—blinatumomab and inotuzumab. They produced a substantial improvement in terms of response rates, with the ability, in most cases, to induce a minimal residual disease (MRD)-negative status. Similarly, T cells engineered to express a CD19-specific chimeric antigen receptor (CAR-T) have yielded sensational results among patients with relapsed/refractory B-ALL, with unexpectedly high MRD-negative complete remissions rates. However, the first studies looking at long-term outcomes after CAR-T infusions told us that a significant fraction of such responses are not durable, and may benefit from a consolidation approach such as an allogeneic HCT