Peter Downie

Results of a phase 1 study utilizing monocyte-derived dendritic cells pulsed with tumor RNA in children and young adults with brain cancer.

We conducted a phase 1 study of 9 pediatric patients with recurrent brain tumors using monocyte-derived dendritic cells pulsed with tumor RNA to produce antitumor vaccine (DCRNA) preparations. The objectives of this study included (1) establishing safety and feasibility and (2) measuring changes in general, antigen-specific, and tumor-specific immune responses after DCRNA. Dendritic cells were derived from freshly isolated monocytes after 7 days of culture with IL-4 and granulocyte-macrophage colony-stimulating factor, pulsed with autologous tumor RNA, and then cryopreserved. Patients received at least 3 vaccines, each consisting of an intravenous and an intradermal administration at biweekly intervals. The study showed that this method for producing and administering DCRNA from a single leukapheresis product was both feasible and safe in this pediatric brain tumor population. Immune function at the time of enrollment into the study was impaired in all patients tested. While humoral responses to recall antigens (diphtheria and tetanus) were intact in all patients, cellular responses to mitogen and recall antigens were below normal. Following DCRNA vaccine, 2 of 7 patients showed stable clinical disease and 1 of 7 showed a partial response. Two of 7 patients who were tested showed a tumor-specific immune response to DCRNA. This study showed that DCRNA vaccines are both safe and feasible in children with tumors of the central nervous system with a single leukapheresis.

Results of a Phase I study utilizing monocyte-derived dendritic cells pulsed with tumor RNA in children with stage 4 neuroblastoma

A Phase I study of 11 pediatric patients with newly diagnosed, Stage 4 neuroblastoma was conducted using monocyte‐derived dendritic cells (DC) pulsed with tumor RNA to produce antitumor vaccines (DCRNA).

Gender differences in the psychosocial experience of parents of children with cancer: a review of the literature

Objective: To build a descriptive literature base of investigated and identified gender differences in the psychosocial experience of parents of children with cancer, in order to guide future research in this area.

Megestrol acetate in pediatric oncology patients may lead to severe, symptomatic adrenal suppression

Despite the widespread use of megestrol acetate (MA) among a growing number of pediatric oncology departments, there is only one published study on the use of MA in children with malignant disease. The objectives of the current study were to examine the effect of MA in improving the nutritional status of children with malignant disease and to describe and consider the implications of MA‐associated adrenal suppression that was found consistently.

Survivors of childhood cancer: An Australian audit of vaccination status after treatment

Survivors of childhood and adolescent cancer are at risk of vaccine preventable diseases and are recommended to receive booster vaccinations post‐chemotherapy. The aim of this study was to describe the compliance of post‐chemotherapy revaccination of childhood cancer survivors relative to current Australian guidelines.

Initial Experience With Gallium-68 DOTA-Octreotate PET/CT and Peptide Receptor Radionuclide Therapy for Pediatric Patients With Refractory Metastatic Neuroblastoma.

Rationale:Pediatric patients with refractory neuroblastoma have limited therapeutic options. Neuroblastoma may express somatostatin receptors (SSTRs) allowing imaging with 68Ga-DOTA-Octreotate (GaTATE) positron emission tomography/computed tomography (PET/CT) and peptide receptor radionuclide therapy (PRRT). We reviewed our experience with this theranostic combination. Materials and Methods:GaTATE studies (8 patients; 2 to 9 years old) were reviewed and compared with 123I-MIBG or posttreatment 131I-MIBG studies. Immunohistochemistry (IHC) for SSTR subtype 2 was performed in 5 patients. Four patients received PRRT. Results:GaTATE PET showed additional disease in 38% (3/8 patients), and upstaged 1 patient by detecting marrow involvement. IHC detected SSTR 2 in all patients assessed. Six patients were deemed suitable for PRRT on imaging. Four patients received 17 cycles of palliative PRRT (10 111In-DOTATATE; 5 177Lu-DOTATATE; 1 combined 111In and 177Lu-DOTATATE; 1 combined 177Lu and 90Y-DOTATATE) with no significant toxicity attributed to PRRT. All had objective responses. Two survivors are now 40 and 56 months from PRRT commencement. Conclusions:GaTATE PET was positive in a high proportion of patients with refractory neuroblastoma, correlating with SSTR 2 on IHC, with additional disease identified compared with MIBG imaging. PRRT seems safe, feasible, with responses observed in patients with progression despite multimodality treatment. These data support ongoing clinical trials in such patients.

Progressive emergence of an oseltamivir-resistant A(H3N2) virus over two courses of oseltamivir treatment in an immunocompromised paediatric patient

A minor viral population of oseltamivir‐resistant A(H3N2) viruses (E119V neuraminidase mutation) was selected and maintained in a continually infected immunocompromised child following initial oseltamivir treatment. A subsequent course of oseltamivir given 7 weeks later rapidly selected for the E119V variant resulting in a near‐pure population of the resistant virus. The study highlights the challenges of oseltamivir treatment of immunocompromised patients that are continually shedding virus and demonstrates the ability of the E119V oseltamivir‐resistant virus to be maintained for prolonged periods even in the absence of drug‐selective pressure.

Adverse hypersensitivity reactions to mesna as adjunctive therapy for cyclophosphamide

Mesna is widely used for the prevention of cyclophosphamide‐related hemorrhagic cystitis. It has been associated with hypersensitivity‐like cutaneous and systemic reactions in adult patients. We report a series of children with malignant disease, who developed such reactions following mesna adminstration and discuss possible mechanisms and management issues. Pediatr Blood Cancer 2007;49:341–343.

Low-Dose Histone Deacetylase Inhibitor Treatment Leads to Tumor Growth Arrest and Multi-Lineage Differentiation of Malignant Rhabdoid Tumors

Purpose: Malignant rhabdoid tumor (MRT) and atypical teratoid rhabdoid tumors (ATRT) are rare aggressive undifferentiated tumors primarily affecting the kidney and CNS of infants and young children. MRT are almost exclusively characterized by homozygous deletion or inactivation of the chromatin remodeling gene SMARCB1. SMARCB1 protein loss leads to direct impairment of chromatin remodeling and we have previously reported a role for this protein in histone acetylation. This provided the rationale for investigating the therapeutic potential of histone deactylase inhibitors (HDACi) in MRT. Experimental Design: Whereas previously HDACis have been used at doses and schedules that induce cytotoxicity, in the current studies we have tested the hypothesis, both in vitro and in vivo, that sustained treatment of human MRT with low-dose HDACi can lead to sustained cell growth arrest and differentiation. Results: Sustained low-dose panobinostat (LBH589) treatment led to changes in cellular morphology associated with a marked increase in the induction of neural, renal, and osteoblast differentiation pathways. Genome-wide transcriptional profiling highlighted differential gene expression supporting multilineage differentiation. Using mouse xenograft models, sustained low-dose LBH589 treatment caused tumor growth arrest associated with tumor calcification detectable by X-ray imaging. Histological analysis of LBH589-treated tumors revealed significant regions of ossification, confirmed by Alizarin Red staining. Immunohistochemical analysis showed increased TUJ1 and PAX2 staining suggestive of neuronal and renal differentiation, respectively. Conclusions: Low-dose HDACi treatment can terminally differentiate MRT tumor cells and reduce their ability to self-renew. The use of low-dose HDACi as a novel therapeutic approach warrants further investigation. Clin Cancer Res; 22(14); 3560–70. ©2016 AACR.

Breastfeeding and Nutrition to 2 Years of Age and Risk of Childhood Acute Lymphoblastic Leukemia and Brain Tumors

Acute lymphoblastic leukemia (ALL) and childhood brain tumors (CBT) are 2 of the most common forms of childhood cancer, but little is known of their etiology. In 2 nationwide case-control studies we investigated whether breastfeeding, age of food introduction, or early diet are associated with the risk of these cancers. Cases aged 0–14 years were identified from Australian pediatric oncology units between 2003 and 2007 (ALL) and 2005 and 2010 (CBT) and population-based controls through nationwide random-digit dialing. Mothers completed questionnaires giving details of infant feeding up to the age of 2 yr. Data from 322 ALL cases, 679 ALL controls, 299 CBT cases, and 733 CBT controls were analysed using unconditional logistic regression. Breastfeeding was associated with a reduced risk of ALL [odds ratio (OR) = 0.52, 95% confidence interval (CI): 0.32, 0.84), regardless of duration. Introduction of artificial formula within 14 days of birth was positively associated with ALL (OR = 1.57, 95% CI: 1.03, 2.37), as was exclusive formula feeding to 6 mo (OR = 1.81, 95% CI: 1.07, 3.05). No associations were seen between breastfeeding or formula use and risk of CBT. Our results suggest that breastfeeding and delayed introduction of artificial formula may reduce the risk of ALL but not CBT.