Intracranial non-germinomatous germ cell tumors in children and adolescents: how can the experience from an uppermiddle-income country contribute to the worldwide effort to improve outcomes?

Background

Non-germinomatous germ cell tumors (NGGCT) accounts for one third of intracranial GCT. While the germinoma group have an excellent overall survival, the standard of practice for children with NGGCT is still under evaluation.

Aims

Describe the results of the of the Brazilian consortium protocol.

Methods

Since 2013, 15 patients with a diagnosis of NGGCT by histopathology and/or serum/cerebrospinal fluid (CSF) tumor markers, βHCG >200mlU/ml and/or positive alpha-fetoprotein were treated with neoadjuvant chemotherapy with carboplatin, cyclophosphamide and etoposide followed by ventricular radiotherapy (RTV) of 18Gy with boost (32Gy) to the primary site. Metastatic patients underwent craniospinal irradiation (CSI) and "slow responders" to the four initial cycles of CT, to autologous stem cell transplantation (ASCT) followed by CSI.

Results

Mean age, 13.1 years. Thirteen males. Primary sites: pineal (n=12), suprasellar (n=2) and bifocal (n=1). Four patients were metastatic at diagnosis. Eight patients had CSF and/or serum alpha-fetoprotein levels > 1,000ng/ml. Tumor responses after chemotherapy demonstrated complete in six cases and partial in seven, with "second-look" surgery being performed in five cases, and two patients presenting viable lesions being referred to ASCT. The main toxicity observed was hematological grades 3/4. Two patients with metastatic disease, one with Down Syndrome and AFP > 1,000ng/ml and the other with choriocarcinoma and pulmonary metastases, developed progressive disease resulting in death, as well as two other patients without evidence of disease, due to endocrinological disorders. Event-free and overall survival at 2 and 5 years were 80% and 72.7%, respectively, with a mean follow-up of 48 months (range, 7-107).

Conclusions

Despite the small number of patients, in our series, treatment with six cycles of chemotherapy and RTV with focal boost for localized disease (n=11) and ACST for identified slow responders (n=2) seem to be effective strategies contributing to the overall effort to improve outcomes of this group of patients.

Outcome of Children and Adolescents With Primary Intracranial Germinoma Treated With Chemotherapy and Reduced Dose-Field Irradiation: A Prospective Brazilian Experience

PURPOSE

This prospective Brazilian single-arm trial was conducted to determine response to chemotherapy and survival after response-based radiotherapy in children with intracranial germinomas, in the setting of a multi-institutional study in a middle-income country (MIC) with significant disparity of subspecialty care.

PATIENTS AND METHODS

Since 2013, 58 patients with histologic and/or serum and CSF tumor marker evaluations of primary intracranial germ cell tumors were diagnosed; 43 were germinoma with HCGβ levels ≤200 mIU/mL and five between 100 and 200 mIU/mL. The treatment plan consisted of four cycles of carboplatin and etoposide followed by 18 Gy whole-ventricular field irradiation (WVFI) and primary site(s) boost up to 30 Gy; 24 Gy craniospinal was prescribed for disseminated disease.

RESULTS

Mean age 13.2 years (range, 4.7-25.5 years); 29 were males. Diagnosis was made by tumor markers (n = 6), surgery (n = 25), or both (n = 10). Two bifocal cases with negative tumor markers were treated as germinoma. Primary tumor location was pineal (n = 18), suprasellar (n = 14), bifocal (n = 10), and basal ganglia/thalamus (n = 1). Fourteen had ventricular/spinal spread documented by imaging studies. Second-look surgery occurred in three patients after chemotherapy. Thirty-five patients achieved complete responses after chemotherapy, and eight showed residual teratoma/scar. Toxicity was mostly grade 3/4 neutropenia/thrombocytopenia during chemotherapy. At a median follow-up of 44.5 months, overall and event-free survivals were 100%.

CONCLUSION

The treatment is tolerable, and WVFI dose reduction to 18 Gy preserves efficacy; we have demonstrated the feasibility of successfully conducting a prospective multicenter trial in a large MIC despite resource disparity.

Diverse mutational spectrum in the 13q14 chromosomal region in a Brazilian cohort of retinoblastoma

Retinoblastoma is a rare childhood tumor caused by the inactivation of both copies of the RB1 gene. Early diagnosis and identification of heritable RB1 mutation carriers can improve the disease outcome and management via genetic counseling. We used the Multiplex Ligation-dependent Probe Amplification (MLPA) method to analyze the RB1 gene and flanking regions in blood samples from 159 retinoblastoma patients previously negative for RB1 point mutations via Sanger sequencing. We detected a wide spectrum of germline chromosomal alterations, ranging from partial loss or duplication of RB1 to large deletions spanning RB1 and adjacent genes. Mutations were validated via karyotyping, fluorescent in situ hybridization (FISH), SNP-arrays (Single Nucleotide Polymorphism-arrays) and/or quantitative relative real-time PCR. Patients with leukocoria as a presenting symptom showed reduced death rate (p = 0.013) and this sign occurred more frequently among carriers of two breakpoints within RB1 (p = 0.05). All unilateral cases presented both breakpoints outside of RB1 (p = 0.0075). Patients with one breakpoint within RB1 were diagnosed at earlier ages (p = 0.017). Our findings characterize the mutational spectrum of a Brazilian cohort of retinoblastoma patients and point to a possible relationship between the mutation breakpoint location and tumor outcome, contributing to a better prospect of the genotype/phenotype correlation and adding to the wide diversity of germline mutations involving RB1 and adjacent regions in retinoblastoma.

An international study evaluating the epidemiology of intracranial germ cell tumors in the native versus immigrant Japanese populations: the need for an international registry

BACKGROUND

Pediatric intra-cranial germ cell tumors (iGCTs) occur at an incidence of 0.6-1.2 cases/million/year in Western countries. The incidence is reported up to 5 times higher in Japan. It is unknown whether this increased incidence is due to genetic predisposition or environment.

METHODS

The incidence of iGCTs in children ages 0-19 years was evaluated from December 1st, 1996-December 1st, 2016 in stable Japanese immigrant populations living abroad and compared to current native Japanese registry data. The incidence of medullobblastoma was used as a control to account for assumptions in the data. Sites were identified based on historical and population data of known large scale emigration from Japan during a period of industrialization from 1868-1912 which resulted in large, stable Japanese immigrant populations abroad. These three representative sites included Lima, Peru, San Paolo, Brazil, and Vancouver, Canada. Data was collected from registry and hospital-based resources within each region.

RESULTS

A review of the Brain Tumor Registry of Japan from 1984-2004 revealed an incidence of 2.5 cases/million/year, lower than previously reported, and a lower incidence of medulloblastoma at 1.2 cases/million/year. Data from Vancouver, Canada, Lima, Peru, and San Paolo, Brazil included a total population of 731,174 Japanese persons. The ratio of all medulloblastoma to iGCT cases in Japan was identified as 1:2 while the ratio was 2:1, 6.5:1, and 5:1, respectively, in the other three locations. The data suggests increased incidence in native Japan may not translate to higher incidence in immigrant Japanese populations abroad and a clear genetic component was not found in our data set.

CONCLUSIONS

A more precise and comprehensive study is needed to determine the cause of this difference in incidence. This study also emphasizes the importance of national and state registries and is a call to collaborate on state and country level epidemiology studies.

LINC-10. The Adequate Treatment of Children and Adolescents with Primary Central Nervous System Germ Cell Tumors (CNS GCT) in a Developing Country

INTRODUCTION: Primary central nervous system germ cell tumors (CNS GCT) are a heterogeneous group of malignancies that can be divided into germinomas and non-germinomatous GCT (NGGCT), accounting for 2-3% of brain tumors in children/adolescents in the Western hemisphere. The study aim is to report the ability to adequately treat Brazilian patients with CNSGCT through a consortium protocol, reporting their treatment, response and survival. Methods: Since 2013, 58 patients with histologic and/or tumor marker (TM) diagnosis of germinoma with/without HCGβ levels ≤200mIU/ml (n=43), five of them between 100-200mIU/ml, received carboplatin/ etoposide (4 cycles) and NGGCT (n=15), received carboplatin/etoposide/cyclophosphamide (6 cycles), all followed by 18Gy ventricular field irradiation and primary site(s) boost. Autologous hematopoietic cell transplant (AuHCT) was undertaken for NGGCT slow responders. Results: Mean age 13.2 years, 42 males. Diagnosis was made by TM (n=19), surgery (n=25) and both (n=12). Two bifocal cases with negative TM and inconclusive biopsy were treated as germinoma. Primary tumor location was pineal (n=30), suprasellar (n=16), bifocal (n=11) and basal ganglia/thalamus (n=1). Eighteen had ventricular/spinal spread. Second-look surgery occurred in seven patients. For the germinoma group, 36 achieved complete responses (CR) after chemotherapy, seven showed residual teratoma/scar. For the NGGCT after 4/6 cycles, six patients showed CR, two failure/progression and seven partial responses (five with negative TM). Two with positive TM underwent AuHCT. Radiotherapy was utilized as described, except in three patients. Four NGGCT patients died (two disease progression, two other causes with no disease). Toxicity was mostly grade 3/4 neutropenia/thrombocytopenia during chemotherapy. At a median follow-up of 40 months, event-free and overall survival was 100% for germinoma and 64.5% NGGCT. Conclusion: The proposed treatment was feasible to be performed in a developing country, with suitable survival even with VFI dose reduction to 18Gy.

Updated safety and efficacy data from an open-label, phase 1/2 study of frontline brentuximab vedotin plus doxorubicin, vinblastine, and dacarbazine (A+AVD) in pediatric patients with advanced-stage classical Hodgkin lymphoma (cHL)

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Background: A+AVD is approved for treatment of adult patients with previously untreated Stage III or IV cHL. Here we present updated results from a phase 1/2 open-label study of frontline A+AVD in treatment-naïve pediatric patients with advanced stage cHL. Methods: Patients aged 5 to < 18 years with CD30+, stage III or IV, newly diagnosed cHL received A+AVD on days 1 and 15 of each 28-day cycle for up to 6 cycles. In phase 1, eight patients were treated with 48 mg/m2 of brentuximab vedotin combined with doxorubicin, vinblastine, and dacarbazine (AVD). Dose-limiting toxicity (DLT) was evaluated from day 1 of cycle 1 to day 56. In phase 2, a further 51 patients were treated with the same regimen. Results presented here refer to phases 1 and 2 combined. Progression-free survival (PFS) was defined as the time from first dose to disease progression; event-free survival (EFS) was defined as the time from first dose to treatment failure, events included disease progression, treatment withdrawal or death. Data cutoff was September 24 2021, when all patients had been on study for at least 2 years. Results: In phase 1, no DLT occurred in the 6 DLT-evaluable patients. The maximum tolerated dose of brentuximab vedotin was not reached and 48 mg/m2 was determined to be the recommended dose. All 59 patients in phase 1 and 2 completed 6 cycles of A+AVD and all experienced ≥1 treatment-emergent adverse event (TEAE). The most common any-grade TEAEs were vomiting (85%), nausea (75%), and neutropenia (58%). In total, 14/59 patients (24%) developed treatment-emergent peripheral neuropathy (PN); 10 patients had PN resolved by end of treatment (EOT); by last contact, 13 patients had resolved PN and one patient had grade 1 paraesthesia. No patients died on study. The PET-negative rate (Deauville 1, 2, or 3) after cycle 2 was 90%. Objective response rate ([ORR], defined as complete response [CR] + partial response [PR] per independent review facility [IRF] at EOT) was 88%, and 76% of patients achieved a CR. Median duration of response and duration of CR were not estimable. Median PFS and EFS had not been reached, suggesting encouraging efficacy of the combination in this pediatric patient population. Additional PFS, EFS and overall survival data will be presented during the meeting. Conclusions: Brentuximab vedotin given at 48 mg/m2 every two weeks in combination with AVD had an acceptable safety profile and was associated with an efficacy benefit in CD30+, treatment-naïve pediatric patients with advanced cHL, supporting A+AVD as a frontline treatment option for this patient population. Clinical trial information: NCT02979522.

MicroRNAs and exosomes: promising new biomarkers in acute myeloid leukemias?

Despite advances in understanding of carcinogenesis and of treatment of acute myeloid leukemia, this neoplasm still has a lethality of at least 30%. The search for biomarkers that can predict the response to treatment in the early stages of the disease is still necessary. In recent years, a new form of cellular communication between tumor and non-neoplastic cells has been discovered: the exchange of information through extracellular vesicles. These are small vesicles released by membrane-coated cells that carry proteins, lipids, messenger RNAs, microRNA and DNA, which can be internalized and promote biological changes in target cells. Exosomes are qualified as a type of extracellular vesicle and, in tumors, carry immunoinhibitory signals that promote the escape of immune control. Recent studies have showed their involvement in communication with the cells of the tumor microenvironment and with chemoresistance in several tumors. To date, there is no information about immunoregulatory microRNAs transported by exosomes and their correlation with clinical evolution during chemotherapy for acute myeloid leukemia. Knowledge about immunomodulatory microRNAs obtained by leukemic cells and transported by exosomes can direct us towards the design of new diagnostic and treatment tools in this type of leukemia.

Macrophage immunomodulation through new polymers that recapitulate functional effects of itaconate as a power house of innate immunity

Itaconate (ITA) is an emerging powerhouse of innate immunity with therapeutic potential that is limited in its ability to be administered in a soluble form. We developed a library of polyester materials that incorporate ITA into polymer backbones resulting in materials with inherent immunoregulatory behavior. Harnessing hydrolytic degradation release from polyester backbones, ITA polymers resulted in the mechanism specific immunoregulatory properties on macrophage polarization in vitro. In a functional assay, the polymer-released ITA inhibited bacterial growth on acetate. Translation to an in vivo model of biomaterial associated inflammation, intraperitoneal injection of ITA polymers demonstrated a rapid resolution of inflammation in comparison to a control polymer silicone, demonstrating the value of sustained biomimetic presentation of ITA.

Low-grade glioma: A rare second tumor in retinoblastoma survivors

Retinoblastoma survivors with a germline RB1 mutation are at elevated risk for secondary (nonocular) malignancy, but their risk for low-grade glioma (LGG) is unknown. We performed a retrospective review of the Memorial Sloan Kettering Cancer Center and the NCI databases that revealed that three of the 837 5-year survivors of hereditary retinoblastoma were diagnosed with an LGG and a fourth patient (but unilateral and without a germline mutation) was identified at another center. Retinoblastoma survivors may be at increased risk for LGG.

DIPG-72. LONG-TERM SURVIVAL OF A CLASSIC DIFFUSE INTRINSIC PONTINE GLIOMA TREATED WITH NIMOTUZUMAB

BACKGROUND

Long-term survival in diffuse intrinsic pontine glioma is rare, and typically associated with atypical imaging and/or atypical clinical course. Although most patients harbor hotspot mutations in H3.1/3-K27M, a proportion of patients have alternate mutations, despite a typical clinicoradiological course. Herein we describe a long-term survivor with a classical presentation, treated with nimotuzumab, highlighting the challenges associated with such cases. CASE REPORT: A 5 year old male, diagnose in 2012 with a 10 day history multiple cranial neuropathies and a right hemiparesis. Cranial MRI revealed a poorly delimited diffuse pontine tumor and secondary hydrocephalus. Tumor biopsy was not performed due to the classic clinical presentation, and he received 54Gy/30 of radiation plus concomitant weekly nimotuzumab 150mg/m2. Initial tumor dimensions were 43x31x28mm. Nimotuzumab 150mg/m2 was continued every 2 weeks. Image assessment at week 12 of treatment revealed 16.9% volume increase, 4 weeks after radiotherapy completion. Nevertheless, subsequent neuroimaging at 24^th, 36^th, 60^th, 96^th and 108^th weeks of nimotuzumab therapy showed a sustained and progressive tumor cytoreduction of 47.5%, 59%, 62.2%, 63.8% and 67%, respectively, when compared with post-radiotherapy dimensions. Currently, the patient is 13y old, good school performance, no neurologic disabilities. The last MRI at 394 weeks of nimotuzumab revealed dimensions of 21x19x14mm which corresponds to 70% of reduction compared with initial volume.

CONCLUSIONS

Our case of progressive cytoreduction over two years of a classic DIPG, diagnosed in the era prior to the discovery of the K27M mutation, highlights the challenges associated with long-term survival of this devastating entity.

MBRS-18. TUMOR SUPPRESSOR p53 DEFINES THE THERAPEUTIC RESPONSES IN TREATMENT OF MEDULLOBLASTOMA

Medulloblastoma (MB) is the most common primary pediatric malignant brain tumor. Current molecular analysis classifies MB into 4 groups, classic (WNT), sonic hedgehog (Shh), group 3, and group 4. Furthermore, atypical p53 signaling is associated with disease progression and confers poor prognosis. This study investigated the correlation of mutational status of p53 and iSO17q with disease progression and metastatic potential. In addition, we used small molecule inhibitors of PI3K (Buparlisib; BKM120) and HDAC (LBH-589) on a p53-mutant MB cell line to find novel therapeutic targets. Efficacy of these drugs were assessed using functional assays (cell proliferation, migration, cell cycle and drug resistance). MB tumors (n=53) were evaluated for GLI-1, GAB-1, NPR, KV1, YAP expression and mutant p53 via immunohistochemistry and correlated to patient outcomes. Results demonstrated that: 1) high expression of GAB-1 and YAP were found in the Shh group, while KV1 expression was present in all subtypes; 2) mutant p53 expression was present in various subsets of MB with no apparent correlation with metastasis or disease progression; 3) patients displaying iSO17q (determined by fluorescence in situ hybridization (FISH) technique) exhibited metastatic disease; 4) LBH-589 and BKM120 caused both time and dose-dependent inhibition of MB cell proliferation and migration; 5) combined treatment of BKM120 and LBH-589 had a synergistic effect; 6) MB cells demonstrated drug-resistance to BKM120. In conclusion, these findings underscore use of Buparlisib and LBH-589 in treatment of MB. Further, the role of mutant p53 in disease progression remains elusive, whereas presence of iSO17q defines metastatic potential.

GCT-58. BRAZILIAN CENTRAL NERVOUS SYSTEM GERM CELL TUMOR CONSORTIUM PROTOCOL

INTRODUCTION

Primary central nervous system (CNS) germ cell tumors (GCT) account for 2–3% brain tumors children/adolescents in Western hemisphere. The report aim is to present the results of a Brazilian CNSGCT consortium protocol.

METHODS

Since 2013, 45 patients with histologic and/or tumor marker (TM) diagnosis of germinoma with/without HCGβ levels≤200mIU/ml (n=33), four between 100-200mIU/ml and NGGCT (n=12), received carboplatin/etoposide/cyclophosphamide (4–6 cycles), followed by 18Gy ventricular field irradiation and primary site(s) boost. Autologous bone marrow transplant (ABMT) was conducted for NGGCT low responders.

RESULTS

Mean age 12.9 years (4.7-20y), 34 males. Diagnosis was made by TM (n=9), surgery (n=19), both (n=15). Two bifocal cases, (-)TM were treated as germinoma. Primary tumor location was pineal (n=20), suprasellar (n=13), bifocal (n=11) and basal ganglia/thalamus (n=1). Fourteen had ventricular/spinal spread. Second-look surgery occurred in 5 patients. For the germinoma group, 26 achieved complete response (CR) after chemotherapy, seven showed residual teratoma/scar. For the NGGCT after 2/4 cycles, four patients showed CR, 2 failure/progression and 6 partial response (4 (-)TM). Two were submitted to ABMT. Radiotherapy was performed as described, except in three. One recurrence to date. Two patients died (endocrinologic complications/progression). Toxicity was mostly grade ¾ neutropenia/thrombocytopenia during chemotherapy. At a median follow-up of 38 months, OS was 100% for Germinoma and 85% NGGCT.

CONCLUSION

The treatment is tolerable and VFI dose reduction to 18Gy seems to preserve efficacy. Further follow-up is warranted to assess the NG group and the slow-responder patients.

LGG-51. BRAF ALTERATIONS IN PEDIATRIC LOW-GRADE GLIOMAS: RESULTS FROM A BRAZILIAN COHORT

BACKGROUND

Pediatric low grade gliomas (PLGG) are the most common central nervous system neoplasms in children. These are driven almost exclusively by alterations in the RAS/MAPK pathway. Specifically, alterations in the BRAF gene have emerged as an important target for therapy. This study aimed to identify the frequency of BRAF alterations in a Brazilian cohort of PLGGs.

RESULTS

Forty-one patients diagnosed between 2001 and 2017 had enough FFPE tissue available for analysis. Real-time PCR test (n=35) was used to assess for BRAFV600E mutations, while BRAF fusions were detected by break-apart fluorescence in situ hybridization (n=30). The histologic distribution was as follows: 73% pilocytic astrocytoma, 12% ganglioglioma, 3% diffuse astrocytoma, 5% pleomorphic xanthoastrocytomas (PXA) and 7% NOS (n = 41). BRAF fusions were present in 21 patients (51%): 17 pilocytic astrocytomas, 2 xanthoastrocytoma, 1 pilomyxoid astrocytoma and 1 diffuse astrocytoma. BRAFV600E was detected in 4 cases (10%): 2 pilocytic astrocytomas, 1 ganglioglioma and 1 PXA. As expected, BRAF translocations were more frequent in pilocytic astrocytomas (p<0.001). From 22 patients treated in our institution, 59% were male with a mean age of 9.7 years, 50% occurred in the posterior fossa and 77% treated by surgery only. One patient relapsed and died from disease (BRAF V600E positive) (follow-up median=44.7 months). These are the first results using a CLIA method showing the frequency of BRAF abnormalities in a Brazilian population. Although preliminary, BRAF alterations are present in 61% of the cases emphasizing the importance of incorporating this analysis in the current work-up guidelines.

MBRS-66. COST-EFFECTIVE METHOD TO INCORPORATE MOLECULAR CLASSIFICATION OF MEDULLOBLASTOMA INTO A LATIN-AMERICAN CLINICAL TRIAL

BACKGROUND

It is now widely accepted that medulloblastoma actually comprises four distinct molecular subgroups, requiring specific treatment strategies. Implementing routine subgrouping in a time and cost effective manner is a major challenge in Latin America, particularly the development of molecular informed clinical trials. Herein we describe the feasibility of reliable and rapid molecular stratification using a qPCR method integrated with immunohistochemistry (IHC) and fluorescent in situ hybridization (FISH – c-myc, monosomy 6) from heterogeneously fixed, low-quality FFPE samples across Latin America.

RESULTS

Fifty-four FFPE samples were classified according to histologic and molecular criteria. Classic medulloblastoma was found in 53.7%, desmoplastic/extensive nodularity in 24.1%, NOS in 16,7% and anaplastic in 5,6%. IHC markers classified patients in three groups (WNT, SHH and non-WNT/non-SHH) in 98% of cases. PCR-based method confirmed results from IHC in 81,5%. Additionally, we were able to detect WNT activation in 2 patients, previously classified as SHH. For both cases, the presence of monosomy 6 further confirmed WNT subgroup. Integration of these three techniques resulted in the following frequencies: WNT (13.0%), SHH (38.9%), group 3 (9.3%), group 4 (20.3%) and non-WNT/non-SHH (18.5%). From 40 patients with clinical information available, 3-year overall survival (n=40) for low, intermediate and high-risk groups were 100%, 60% and 20%, respectively (p&lt;0.05), based only in molecular criteria, which confirmed the prognostic importance of this method.

CONCLUSIONS

At an estimated cost of $220 per patient, we are able to implement central molecular diagnosis for the incorporation into a prospective clinical trial protocol in Latin America.

EPID-12. TEMPORAL AND GLOBAL GEOGRAPHIC VARIATION IN THE INCIDENCE OF PEDIATRIC CNS TUMORS, 1998–2012

AIMS

To describe the temporal and geographic variation in the incidence of pediatric CNS malignancies worldwide, presenting analyses by sex, period, region, and histological subtype between 1998 and 2012.

METHODS

Data were extracted from volumes IX to XI of the Cancer Incidence in 5 Continents, covering the periods 1998–2002 (1), 2003–2007 (2), and 2008–2012 (3). We pooled data from 44 countries, classifying them into 6 regions (Africa (AF), Asia (AS), Oceania (O), Europe (E), Central/South America (CSA), North America (NA)). Age-standardized incidence rates (ASIR per million, 0–19 years) were calculated and temporal variation was evaluated using incidence rate ratios (IRR) (95% CI).

RESULTS

The highest incidence (Period 3) was observed in NA (34.0 and 30.2 for males and females, respectively). Astrocytic tumors were predominant in all regions, with percentages ranging between 24.5% (E, females) and 45.6% (NA, females). Increasing trends (Period 3 x 1) were observed in AS (IRR=1.15, 95% CI 1.06–1.25), CSA (IRR=1.25, 95% CI 1.01–1.55), and NA (IRR=1.05, 95% CI 1.03–1.07), for males and in AS (IRR=1.15, 95% CI 1.05–1.26) and NA (IRR=1.08, 95% CI 1.06–1.11) for females. Geographic discrepancies in time-trends were observed for astrocytomas, ependymomas, medulloblastomas, other embryonal tumors, and other specified tumors. Reductions in the incidence of unspecified tumors from period 1 to 3 were noted in E, AS, and NA, ranging from -20% (E, females) to -66% (AS, females).

CONCLUSIONS

Heterogeneous trends and improvement in the registration of histological types were noted. Geographic variation can help to raise hypotheses to investigate etiologic factors.

GCT-59. EPIDEMIOLOGY OF PEDIATRIC INTRA-CRANIAL GERM CELL TUMORS: COMPARING THE INCIDENCE OF INTRA-CRANIAL GERM CELL TUMORS IN THE NATIVE JAPANESE POPULATION AND IMMIGRANT JAPANESE POPULATIONS ABROAD

Pediatric intra-cranial germ cell tumors (iGCTs) occur at an incidence of 0.6–1.2 cases/million/year in Western countries. The incidence is reported up to 5 times higher in the Japan. It is unknown whether this increased incidence is due to tumor biology or environment. The incidence of iGCTs in children ages 0–19 years was evaluated from 12/1/96-12/1/2016 in stable Japanese immigrant populations living abroad compared to current native Japanese registry data. Medulloblastoma incidence was used as a control to account for assumptions in the data. A review of the Brain Tumor Registry of Japan from 1984–2004 revealed an incidence of 2.5 cases/million/year and a lower incidence of medulloblastoma at 1.1 cases/million/year. Sites outside of Japan included Vancouver, Canada, Lima, Peru, and San Paolo, Brazil and together included a population of 853,174 Japanese persons. Within this population, 0 cases of iGCT were identified over a 20-years. The ratio of medulloblastoma to iGCT cases in Japan was identified as 1:2 while the ratio was 2:1, 6.5:1, and 5:1, respectively, in the other three locations. The data suggests increased incidence in the native Japan may not translate to higher incidence in immigrant Japanese populations abroad and a clear genetic component was not found in this preliminary data set. A more precise and comprehensive study is needed to determine the cause of this difference in incidence. This study also emphasizes the importance of national and state registries and is a call to collaborate on state and country level epidemiology studies.

Metronomic Chemotherapy for Children in Low- and Middle-Income Countries: Survey of Current Practices and Opinions of Pediatric Oncologists

PURPOSE

Low- and middle-income countries (LMICs) experience the burden of 80% of new childhood cancer cases worldwide, with cure rates as low as 10% in some countries. Metronomics combines frequent administrations of low-dose chemotherapy with drug repurposing, which consists of using already-approved drugs for new medical applications. With wide availability, limited costs, and little infrastructure needs, metronomics can be part of constraint-adapted regimens in these resource-limited settings—with the understanding that metronomics shall not be a substitute for standard treatments when available and doable. Our study aims to describe the experience, practices, opinions, and needs in metronomics of physicians working in LMICs.

METHODS

An online questionnaire was sent to more than 1,200 physicians in pediatric oncology networks in LMICs. Items included the type of center, physician’s demographics, experience in pediatric oncology, and experience with current knowledge of metronomics. Opinions and perspectives were explored using multiple-answer and open questions.

RESULTS

Of physicians, 17% responded. Of respondents, 54.9% declared that they had already used a metronomic regimen. The most frequently cited repositioned drugs were celecoxib (44%) followed by propranolol and valproic acid (17%). Respondents highlighted the advantages of outpatient use (20%) and expected low toxicity (24%). In considering the drawbacks of metronomics, 47% of responses highlighted the lack of scientific evidence or guidelines, 33% the availability or affordability of drugs, and 18% the problem of acceptance or compliance. Of physicians, 79% believed that use of metronomics will spread in LMICs in the near future and 98% of them were willing to participate in international metronomic protocols or registries.

CONCLUSION

Metronomics is already used in LMICs and is a potential answer to unmet needs in pediatric oncology. There is room for improvement in the availability of drugs and a necessity to develop collaborative protocols and research to generate level A evidence.

Prevention of cisplatin-induced ototoxicity in children and adolescents with cancer: a clinical practice guideline

Despite ototoxicity being a prevalent consequence of cisplatin chemotherapy, little guidance exists on interventions to prevent this permanent and progressive adverse event. To develop a clinical practice guideline for the prevention of cisplatin-induced ototoxicity in children and adolescents with cancer, we convened an international, multidisciplinary panel of experts and patient advocates to update a systematic review of randomised trials for the prevention of cisplatin-induced ototoxicity. The systematic review identified 27 eligible adult and paediatric trials that evaluated amifostine, sodium diethyldithiocarbamate or disulfiram, systemic sodium thiosulfate, intratympanic therapies, and cisplatin infusion duration. Regarding systemic sodium thiosulfate, the panel made a strong recommendation for administration in non-metastatic hepatoblastoma, a weak recommendation for administration in other non-metastatic cancers, and a weak recommendation against its routine use in metastatic cancers. Amifostine, sodium diethyldithiocarbamate, and intratympanic therapy should not be routinely used. Cisplatin infusion duration should not be altered as a means to reduce ototoxicity. Further research to determine the safety of sodium thiosulfate in patients with metastatic cancer is encouraged.

Abstract 3982: Dual inhibition of HDAC and PI3 kinase signaling pathways with CUDC-907 in treatment of p53-driven medulloblastoma

Comprehensive studies of the medulloblastoma (MB) genome, epigenome and transcriptome have placed MB in four molecular subgroups: WNT, SHH, and two non-WNT/non-SHH: Group 3 and Group 4. Furthermore, studies suggest that p53-mutated SHH MBs frequently harbor genetic anomalies involving MYCN and GLI2 amplifications, which confer poor prognosis and resistance to treatments. The phosphatidylinositol-3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) intracellular signaling pathway that regulates cell growth, survival and invasion, is commonly deregulated in MB. Therefore, the PI3K/Akt/mTOR pathway may be a suitable target for therapeutic intervention. Moreover, Histone deacetylases (HDAC) regulate cancer initiation and progression, and studies have shown that small molecule inhibitors of HDAC can effectively limit MB proliferation. We aim to determine the status of tumor suppressor gene p53 in defining metastatic potential in SHH-MB and to establish the therapeutic efficacy of targeting these pathways in p53-driven MB cells with a dual agent or individual agents. Immunohistochemistry and FISH were used to determine the status of mutant p53 and MYC amplification or iso-p53, respectively, in MB tumors (n=41). p53-mutant MB cell line was used to investigate the signaling pathway that regulates proliferation, migration, and drug resistance using inhibitors of HDAC (LBH-589) and PI3K/mTOR (BKM-120/rapamycin) or CUDC-907 (dual inhibitor of HDACs and the PI3K/AKT). Results demonstrated that: 1) GAB-1 was highly expressed in the Shh group (82%) and KV1 expression was evenly distributed in all subtypes; 2) loss of p53 and overexpression of MYC varied in each subtype, but did not correlate with metastasis; 3) combined treatment with LBH-589 and BKM-120 or single treatment with CUDC-907 reduced cell proliferation, migration and S-phase entry; 4) MB cells were resistant to BKM -120, while LBH-589 or CUDC-907 caused apoptosis; 5) tumor formation was suppressed by BKM-120 given with mTOR inhibitors; 6) AKT and 4E-BP1 dephosphorylated following treatments with BKM-120 or CUDC-907. In conclusion, despite current clinical limitations, dual HDAC and PI3K inhibitors may benefit the understanding of aberrant signaling pathways in genetically driven MB, and may provide basis for future targeted therapies.

Citation Format: Jennifer S. Ronecker, Julia Pazniokas, Anubhav G. Amin, Raphael Salles Scortegagna de Medeiros, Sidnei Epelman, Chirag Ghandi, Nelci Zanon, Meic H. Schmidt, Meena Jhanwar-Uniyal. Dual inhibition of HDAC and PI3 kinase signaling pathways with CUDC-907 in treatment of p53-driven medulloblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3982.

Frequency of EBV LMP-1 Promoter and Coding Variations in Burkitt Lymphoma Samples in Africa and South America and Peripheral Blood in Uganda

Epstein-Barr virus (EBV) is linked to several cancers, including endemic Burkitt lymphoma (eBL), but causal variants are unknown. We recently reported novel sequence variants in the LMP-1 gene and promoter in EBV genomes sequenced from 13 of 14 BL biopsies. Alignments of the novel sequence variants for 114 published EBV genomes, including 27 from BL cases, revealed four LMP-1 variant patterns, designated A to D. Pattern A variant was found in 48% of BL EBV genomes. Here, we used PCR-Sanger sequencing to evaluate 50 additional BL biopsies from Ghana, Brazil, and Argentina, and peripheral blood samples from 113 eBL cases and 115 controls in Uganda. Pattern A was found in 60.9% of 64 BL biopsies evaluated. Compared to PCR-negative subjects in Uganda, detection of Pattern A in peripheral blood was associated with eBL case status (odds ratio [OR] 31.7, 95% confidence interval: 6.8⁻149), controlling for relevant confounders. Variant Pattern A and Pattern D were associated with eBL case status, but with lower ORs (9.7 and 13.6, respectively). Our results support the hypothesis that EBV LMP-1 Pattern A may be associated with eBL, but it is not the sole associated variant. Further research is needed to replicate and elucidate our findings.

Highlights from the 1st Latin American meeting on metronomic chemotherapy and drug repositioning in oncology, 27-28 May, 2016, Rosario, Argentina

Following previous metronomic meetings in Marseille (2011), Milano (2014), and Mumbai (2016), the first Latin American metronomic meeting was held in the School of Medical Sciences, National University of Rosario, Rosario, Argentina on 27 and 28 of May, 2016. For the first time, clinicians and researchers with experience in the field of metronomics, coming from different countries in Latin America, had the opportunity of presenting and discussing their work. The talks were organised in three main sessions related to experience in the pre-clinical, and clinical (paediatric and adult) areas. The different presentations demonstrated that the fields of metronomic chemotherapy and repurposing drugs in oncology, known as metronomics, constitute a branch of cancer therapy in permanent evolution, which have strong groups working in Latin

America, both in the preclinical and the clinical settings including large, adequately designed randomised studies. It was shown that metronomics offers treatments, which, whether they are combined or not with the standard therapeutic approaches, are not only effective but also minimally toxic, with the consequent improvement of the patient’s quality of life, and inexpensive, a feature very important in low resource clinical settings. The potential use of metronomic chemotherapy was proposed as a cost/effective treatment in low-/middle-income countries, for adjuvant therapy in selected tumours. The fundamental role of the governmental agencies and non-governmental alliances, as the Metronomic Global Health Initiative, in supporting this research with public interest was underlined.

Epstein-Barr virus from Burkitt Lymphoma biopsies from Africa and South America share novel LMP-1 promoter and gene variations

Epstein Barr virus (EBV) sequence variation is thought to contribute to Burkitt lymphoma (BL), but lack of data from primary BL tumors hampers efforts to test this hypothesis. We directly sequenced EBV from 12 BL biopsies from Ghana, Brazil, and Argentina, aligned the obtained reads to the wild-type (WT) EBV reference sequence, and compared them with 100 published EBV genomes from normal and diseased people from around the world. The 12 BL EBVs were Type 1. Eleven clustered close to each other and to EBV from Raji BL cell line, but away from 12 EBVs reported from other BL-derived cell lines and away from EBV from NPC and healthy people from Asia. We discovered 23 shared novel nucleotide-base changes in the latent membrane protein (LMP)-1 promoter and gene (associated with 9 novel amino acid changes in the LMP-1 protein) of the 11 BL EBVs. Alignment of this region for the 112 EBV genomes revealed four distinct patterns, tentatively termed patterns A to D. The distribution of BL EBVs was 48%, 8%, 24% and 20% for patterns A to D, respectively; the NPC EBV's were Pattern B, and EBV-WT was pattern D. Further work is needed to investigate the association between EBV LMP-1 patterns with BL.

Fifteen Years' Experience of the Brazilian Osteosarcoma Treatment Group (BOTG): A Contribution from an Emerging Country

PURPOSE

Little information is available regarding the tumor features, prognostic factors, and treatment results in children and adolescents and young adults (AYAs) with osteosarcoma diagnosed in developing countries. We reviewed the results of three observational cohorts of osteosarcoma patients treated in an emerging country.

METHODS

A total of 604 patients below the age of 30 years with high-grade osteosarcoma were prospectively enrolled in the Brazilian Osteosarcoma Treatment Group (BOTG) studies III, IV, and V. Gender, age, time from onset of symptoms to diagnosis, primary tumor site, presence or absence of metastases at diagnosis, tumor size, type of surgery (limb-sparing or amputation), treatment protocol, and histological response were correlated with survival.

RESULTS

The estimated 5-year overall survival and event-free survival (EFS) rates for the 553 eligible patients were 49% and 39% respectively; of the 390 non-metastatic patients included in the total, overall- and event-free survival were 59% and 48% respectively. Metastases at diagnosis, primary tumor site, type of surgery, and histological response were significant predictors of overall survival and EFS in univariate and multivariate analysis, whereas tumor size and treatment protocol lost prognostic significance in multivariate analysis.

CONCLUSION

We report on the outcome of three consecutive studies for the treatment of osteosarcoma carried out in Brazil over 15 years. Although the survival rates presented are below those reported in current literature, it represents the result of a favorable experience gathered from the national collaborative work.

The adolescent and young adult with cancer: state of the art--brain tumor

The management of adolescents and young adults with brain tumors, which consist of many different histologic subtypes, continues to be a challenge. Better outcome with a decrease of the side effects of the disease and therapy and improvement of quality of life has been demonstrated in recent decades for some tumors. Significant differences in survival and cure are also observed between adult and pediatric tumors of the same histologic grade. Genetic, developmental, and environmental factors likely influence the type of tumor and response observed, even though no clear pathologic features differentiate these lesions among children, adolescents, and adults. Similarly, treatment strategies are not identical among these populations; most patients receive surgery, followed by radiation therapy and multiagent chemotherapy. Advances in understanding the biology underlying the distribution of tumors in adolescents and young adults may influence the development of prospective trials. A more individualized view of these tumors will likely influence stratification of patients in future studies as well as selection for targeted agents. Accordingly, outcomes may improve and long-term morbidities may decrease.

First results of prophylaxis for bacterial and fungal infections in pediatric patients with high-risk acute lymphocytic leukemia (ALL)

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Background: Bacterial and invasive fungal infections remain a major contributor to treatment related morbidity and mortality in cancer patients. It has been published data of potential prevention; in immunocompromised hosts derive primarily from adult studies. However, children differ from adults in terms of the infections types as they develop or manifest, as well as their metabolism of treatment agents. From April 2010 to January 2011, 6 ALL patients received 35 intensive chemotherapy cycles during the first 6 months after diagnosis, 2 died due to infection. Methods: From April 2011 to January 2012, a prospective analysis in 8 high risk ALL patients ( BFM criteria) after 31 cycles of intensive chemotherapy were performed during the first 6 months of treatment followed by antibacterial and antifungal prophylaxis. Drugs are: ciprophloxacin 1000mg per day when weight highest than 30 kg and 500mg per day when lower weigh and fluconazole 100mg per day for the lower weigh and 150mg for the higher. All patient received granulocyte colony-stimulating factor after each cycles until complete neutrophils recovery. Results: In 20/31 cycles, hospitalization was needed, due to febrile neutropenia. Diarrhea, sepsis and renal failure were other reasons for hospitalization. Platelet transfusions and blood transfusions were performed in 12 and 9 hospitalization respectively. The majority of proven infections (n=7) were bacterial, Gram negative (Pseudomonas aeruginosa and Klebsiella spp), Gram positive, Candida (1 cycle). Hospitalization time was between 2 and 25 days (median time 10 days). In 4 cycles, intensive care unit was needed. No death occurred. Conclusions: Bacterial and fungal infections continue to be a leading cause of morbidity and mortality in children receiving intensive therapy. Pharmacologic prophylaxis can contribute to decrease mortality due to infection in this population.

Double akylating agents treatment with ifosfamide (IFOS) and cyclophosphamide (CYCLO) for relapsed pediatric solid tumors

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Background: CYCLO and IFOS are two of the most active agents in childhood cancer. There is non-cross resistance between CYCLO and IFOS and they have dissimilar toxic side effects. In vitro, tumor model systems document that alkylator resistance may be overcome by several fold increases in drug concentration. We developed a strategy in attempt to limit side effects and increase anticancer activity of high doses oxazaphosphorines therapy: an association of IFOS plus CYCLO, giving an equivalent to 20g/m2 of IFOS or 5g/m2 of CYCLO. The schedule is the association of these two drugs: CYCLO 2,5g/m2 (corresponding to 10g/m2 of IFOS) plus IFOS 10g/m2. Methods: Eligibility included recurrent/refractory measurable disease, life expectancy > 6 weeks, adequate renal, hepatic and bone marrow function. CYCLO (2,5g/m2) and IFOS (10g/m2) with Mesna, with interval of 21 days. Responses were evaluated after 2 cycles.So far, 13 patients were enrolled: median age 17 years (5-26), 9M:4F,6 osteosarcoma, 1 hemangioperycitoma, 2 medulloblastoma, 1 nasopharyngeal carcinoma, 1 Wilms tumor,1 synoviosarcoma, 1 retinoblastoma. Six patients received IFOS previously (Total= 38 - 63 g/m²) and 5 CYCLO. Results: Thirty four cycles were evaluated. Toxicity was tolerable with no death. Main adverse event was neutropenia grade (GR) 4 in all cycles, median duration of seven days (3-15), GCS-F was used in all cycles; anemia GR 3 and 4 and thrombocytopenia GR 4 in 14 cycles; infection GR 3 and 4 in 15 cycles; hemorrhage cystitis GR 1 in 2 cycles and neurologic toxicity GR 2 in 6 cycles. No acute renal toxicity was observed. Responses were 2 complete response (CR), 5 partial responses (PR), 3 stable disease, and 3 progress disease. Conclusions: This schedule is feasible with high response rate (CR+PR=54%). Due to lack of new agents, innovative approaches for high risk patients can have a potential benefit. More patients are warranted.

Paediatric cancer in low-income and middle-income countries

Patterns of cancer incidence across the world have undergone substantial changes as a result of industrialisation and economic development. However, the economies of most countries remain at an early or intermediate stage of development-these stages are characterised by poverty, too few health-care providers, weak health systems, and poor access to education, modern technology, and health care because of scattered rural populations. Low-income and middle-income countries also have younger populations and therefore a larger proportion of children with cancer than high-income countries. Most of these children die from the disease. Chronic infections, which remain the most common causes of disease-related death in all except high-income countries, can also be major risk factors for childhood cancer in poorer regions. We discuss childhood cancer in relation to global development and propose strategies that could result in improved survival. Education of the public, more and better-trained health professionals, strengthened cancer services, locally relevant research, regional hospital networks, international collaboration, and health insurance are all essential components of an enhanced model of care.

Prognostic-significance of p53 mutations in small non-cleaved cell lymphomas

We have assessed the prognostic significance of mutations in the p53 tumor suppressor gene in patients with small non-cleaved cell lymphomas. In this retrospective pilot study we have, been able to evaluate the response to therapy of 21 previously untreated patients. Seven of these patients (33%) had tumors which contained a p53 mutation at presentation. Five of the 7 patients with mutant p53 relapsed and 4 died of progressive disease whereas none of the patients with wild type p53 relapsed and none died of progressive disease. These preliminary results strongly suggest that the presence of a mutated p53 gene is an unfavorable prognostic factor. p53 mutations could be used as a parameter in risk-adapted therapy protocols, or could even provide an appropiate target for therapy.

Exposure to magnetic fields and childhood acute lymphocytic leukemia in São Paulo, Brazil

BACKGROUND

Epidemiological studies have identified increased risks of leukemia in children living near power lines and exposed to relatively high levels of magnetic fields. Results have been remarkably consistent, but there is still no explanation for this increase. In this study we evaluated the effect of 60 Hz magnetic fields on acute lymphocytic leukemia (ALL) in the State of São Paulo, Brazil.

METHODS

This case-control study included ALL cases (n=162) recruited from eight hospitals between January 2003 and February 2009. Controls (n=565) matched on gender, age, and city of birth were selected from the São Paulo Birth Registry. Exposure to extremely low frequency magnetic fields (ELF MF) was based on measurements inside home and distance to power lines.

RESULTS

For 24h measurements in children rooms, levels of ELF MF equal to or greater than 0.3microtesla (μT), compared to children exposed to levels below 0.1 μT showed no increased risk of ALL (odds ratio [OR] 1.09; 95% confidence interval [95% CI] 0.33-3.61). When only nighttime measurements were considered, a risk (OR 1.52; 95% CI 0.46-5.01) was observed. Children living within 200 m of power lines presented an increased risk of ALL (OR 1.67; 95% CI 0.49-5.75), compared to children living at 600 m or more of power lines. For those living within 50 m of power lines the OR was 3.57 (95% CI 0.41-31.44).

CONCLUSIONS

Even though our results are consistent with the small risks reported in other studies on ELF MF and leukemia in children, overall our results do not provide support for an association between magnetic fields and childhood leukemia, but small numbers and likely biases weaken the strength of this conclusion.

Prognostic impact of MYCN, DDX1, TrkA, and TrkC gene transcripts expression in neuroblastoma

BACKGROUND

The aims of this study were to define the mRNA expression profiles of MYCN, DDX1, TrkA, and TrkC in biopsy tumor samples from 64 Brazilian patients with neuroblastomas of different risk stages and to correlate altered expression with prognostic values.

PROCEDURE

Patients were retrospectively classified into low- (n = 11), intermediate- (n = 18), and high-risk (n = 35) groups using standard criteria. The mRNA levels of the above genes were measured by quantitative real-time polymerase chain reaction. Univariate analyses were performed and survival curves were plotted by the Kaplan-Meier method.

RESULTS

Of the 64 patients, 53% were female and 62.5% were older than 18 months. The 5-year overall survival (OS) for the entire cohort was 40.3%, with inferior median OS in patients identified in the intermediate- and high-risk groups. A significant difference in OS with respect to TrkA mRNA expression was found for the high-risk group vs. either the low- or intermediate-risk groups (P < 0.01, log rank test). Within the intermediate-risk group, neuroblastoma patients with positive TrkA mRNA expression had better clinical outcomes than patients with no TrkA transcript expression (P = 0.004). Another difference in OS was only found between the intermediate- and high-risk groups (P < 0.027, log rank test). No significant correlation of mRNA expression and survival outcome could be detected for the MYCN, DDX1.

CONCLUSIONS

Positive expression of TrkA mRNA may be a clinically useful addition to the current risk classification system, allowing the identification of NB tumors with favorable prognosis.

Retinoblastoma: one world, one vision

Retinoblastoma is curable when diagnosed early and treated appropriately; however, the prognosis is dismal when the basic elements of diagnosis and treatment are lacking. In developing countries, poor education, lower socioeconomic conditions, and inefficient health care systems result in delayed diagnosis and suboptimal care. Furthermore, the complexity of multidisciplinary care required is seldom possible. Whereas ocular salvage is a priority in the Western world, death from retinoblastoma is still a major problem in developing countries. To bring the 2 ends of this spectrum together and provide a forum for discussion, the "One World, One Vision" symposium was organized, at which clinicians and researchers from various cultural, geographic, and socioeconomic backgrounds converged to discuss their experiences. Strategies for early diagnosis in developing countries were discussed. Elements of the development of retinoblastoma centers in developing countries were discussed, and examples of successful programs were highlighted. An important component in this process is twinning between centers in developing countries and mentor institutions in high-income countries. Global initiatives by nongovernmental organizations such as the International Network for Cancer Treatment and Research, Orbis International, and the International Agency for Prevention of Blindness were presented. Treatment of retinoblastoma in developing countries remains a challenge; however, it is possible to coordinate efforts at multiple levels, including public administrations and nonprofit organizations, to improve the diagnosis and treatment of retinoblastoma and to improve the outcome for these children.

Urine mesna excretion after intravenous and oral dosing in ifosfamide-treated children

PURPOSE

To describe mesna excretion in children.

PATIENTS AND METHODS

We studied 14 children (aged 1-18 years) who received 1.8 g/m(2) of ifosfamide per day for 5 days. For uroprotection, the children were given intravenous mesna (equal to 20% of the ifosfamide dose) followed by two oral doses (each equal to 40% of the ifosfamide dose). The concentrations of mesna and the metabolite dimesna were measured in urine samples collected on treatment days 1 and 5.

RESULTS

Of 14 patients enrolled, 11 (aged 4-18 years) were evaluable. The profiles of mesna excretion rates were similar on days 1 and 5. Mesna excretion declined rapidly over 1-2 h after intravenous dosing. Increases in mesna excretion after oral dosing lagged by 2-4 h. About 21% of the mesna administered was excreted unchanged over 24 h on both days 1 and 5. The proportion excreted varied by severalfold between patients, but there was no association with age.

CONCLUSION

The profile of mesna excretion after intravenous and oral dosing in these children was similar to that in reported studies of ifosfamide-treated adults.

Lipopolysaccharide-stimulated or granulocyte-macrophage colony-stimulating factor-stimulated monocytes rapidly express biologically active IL-15 on their cell surface independent of new protein synthesis

Although IL-15 shares many of the biological activities of IL-2, IL-2 expression is primarily under transcriptional regulation, while the mechanisms involved in the regulation of IL-15 are complex and not completely understood. In the current study, we found that CD14(+) monocytes constitutively exhibit both IL-15 mRNA and protein. IL-15 protein was found stored intracellularly and stimulation of CD14(+) monocytes with either LPS or GM-CSF resulted in mobilization of IL-15 stores to the plasma membrane. This rapidly induced surface expression was the result of a translocation of preformed stores, confirming that posttranslational regulatory stages limit IL-15, because it was not accompanied by an increase in IL-15 mRNA and occurred independent of de novo protein synthesis. After fixation, activated monocytes, but not resting monocytes, were found to support T cell proliferation, and this effect was abrogated by the addition of an IL-15-neutralizing Ab. The presence of preformed IL-15 stores and the ability of stimulated monocytes to mobilize these stores to their surface in an active form is a novel mechanism of regulation for IL-15.

Selective surgical indication in the management of neutropenic children presenting with acute abdomen

As the treatment of pediatric malignancies improves and survival increases, the diagnosis of acute abdomen in these patients also becomes more common. Nevertheless, the management of this condition is still controversial. The authors report their experience in treating 12 neutropenic children with acute abdomen. The charts of 12 neutropenic patients with a diagnosis of acute abdomen treated at Boldrini Children's Cancer Center in Campinas, Brazil, between 1991 and 1996, were reviewed. Therapeutic strategy included an initial period of bowel rest, general supportive measures, and broad-spectrum antibiotics while waiting for the neutrophil count to rise. Three patients recovered completely without surgery, 8 underwent late surgery without complications, and 1 died due to uncontrolled sepsis before surgery. The treatment of acute abdomen in neutropenic children remains controversial. As shown in the present series, an initial nonoperative approach with selective surgical indication appears to be safe and to yield good results. Supportive treatment, until the neutrophil count rises, followed by surgery, if necessary, appears to be a sound therapeutic approach for neutropenic children with acute abdomen.

Pseudomonas aeruginosa exoenzyme S induces transcriptional expression of proinflammatory cytokines and chemokines

Pseudomonas aeruginosa infection of cystic fibrosis patients causes lung damage that is substantially orchestrated by cytokines. In this study, multi-gene probe analysis was used to characterize the ability of the P. aeruginosa mitogen, exoenzyme S, to induce proinflammatory and immunoregulatory cytokines and chemokines. Exoenzyme S strongly induced transcription of proinflammatory cytokines and chemokines (tumor necrosis factor alpha, interleukin-1alpha [IL-1alpha], IL-1beta, IL-6, IL-8, MIP-1alpha, MIP-1beta, MCP-1, RANTES, and I-309), modest transcription of immunoregulatory cytokines (IL-10 and IL-12p40), and weak transcription of Th1 cytokines (IL-2 and gamma interferon). The response occurred early and subsided without evolving over time. These data suggest that cells responding to exoenzyme S would rapidly express proinflammatory cytokines and chemokines that may contribute to pulmonary inflammation in cystic fibrosis.

Pre-operative control of arterial hypertension using ketoconazole in pediatric patients with adrenocortical tumors

Adrenocortical tumors are rare in childhood, appearing more frequently in some regions such as South and South-eastern regions of Brazil and India. Common clinical signs include virilization, Cushing's syndrome, feminization and hypertension, either isolated or in association. The aim of this report is to present our experience with the pre-operative use of ketoconazole in children with an adrenocortical tumor to control elevated blood pressure levels non-responsive to the usual treatment. Over the last 16 years, of 46 children diagnosed as having adrenocortical tumor, 17 developed hypertension (diastolic pressure greater than the 95th percentile for age and sex according to data from the Task Force on Blood Pressure Control in Children), associated with virilization and/or Cushing's syndrome. In three of these 17 patients, conventional antihypertensive therapy failed, and they were treated with ketoconazole (200-300 mg/day). This resulted in rapid control of the blood pressure. It is concluded that in selected patients, ketoconazole may be useful adjuvant therapy for the palliative control of the arterial hypertension secondary to adrenocortical tumors, without side effects.

Chemotherapy of medulloblastoma

Recent advances in neurosurgical techniques and diagnostic imaging capabilities have facilitated gross total resection and accurate staging of disease extent in a greater proportion of patients. The addition of chemotherapy to surgery and craniospinal radiation has improved the outcome of patients diagnosed with medulloblastoma. Long-term follow-up studies have documented the neuroendocrine and neuropsychological deficits seen in the survivors. This paper reviews key studies using all three modalities over the past two decades and presents on-going therapeutic strategies using a risk-adapted approach. Further areas of basic research and evolving data on studies in relapsed patients are also briefly discussed.