SciCombinator

Discover the most talked about and latest scientific content & concepts.

Journal: Pediatric blood & cancer

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Cisplatin may cause permanent cochlear damage by changing cochlear frequency selectivity and can lead to irreversible sensorineural hearing loss. High-frequency audiometry (HFA) is able to assess hearing frequencies above 8,000 Hz; hence, it has been considered a high-quality method to monitor and diagnose early and asymptomatic signs of ototoxicity in patients receiving cisplatin.

Concepts: Audiogram, Hertz, Cochlear implant, Sensorineural hearing loss, Otology, Ear, Tinnitus, Ototoxicity

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Hemophilia A and hemophilia B are caused by congenital deficiency of factor VIII and factor IX, respectively, and may lead to recurrent, spontaneous bleeding into the muscles and joints resulting in disabling arthropathy. Effective management is available in the form of prophylactic infusions of clotting factor concentrates which have been demonstrated to prevent bleeding episodes and greatly improve the quality of life of these patients. Prophylaxis is, however, expensive. Usual dosing regimens rely on weight based calculations but dosing with an understanding of an individual’s pharmacokinetic response has been demonstrated to be more effective in predicting clotting factor levels that protect against bleeding episodes. Standard pharmacokinetic studies require a prohibitive number of time sampling points but recent population or Bayesian pharmacokinetics can be used to provide an accurate estimation of an individual’s pharmacokinetic response using a limited number of sampling time points. The use of population pharmacokinetics has the potential to greatly increase the use of pharmacokinetic dosing regimens and optimize the use of clotting factor concentrates in patients with hemophilia. Pediatr Blood Cancer 2012; 60: S27-S29. © 2012 Wiley Periodicals, Inc.

Concepts: Coagulation system, Pharmacokinetics, Factor IX, Factor X, Blood, Haemophilia A, Haemophilia B, Coagulation

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Renal malignancies are among the most prevalent pediatric cancers. The most common is favorable histology Wilms tumor (FHWT), which has 5-year overall survival exceeding 90%. Other pediatric renal malignancies, including anaplastic Wilms tumor, clear cell sarcoma, malignant rhabdoid tumor, and renal cell carcinoma, have less favorable outcomes. Recent clinical trials have identified gain of chromosome 1q as a prognostic marker for FHWT. Upcoming studies will evaluate therapy adjustments based on this and other novel biomarkers. For high-risk renal tumors, new treatment regimens will incorporate biological therapies. A research blueprint, viewed from the perspective of the Children’s Oncology Group, is presented. Pediatr Blood Cancer © 2012 Wiley Periodicals, Inc.

Concepts: Wilms' tumor, Lung cancer, Malignancy, Medicine, Types of cancer, Tumor, Oncology, Cancer

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BACKGROUND: Growth differentiation factor 15 (GDF15), a divergent TGFβ superfamily, has recently been implicated in the modulation of iron homeostasis, acting as an upstream negative regulator of hepcidin, the key iron regulatory hormone produced primarily by hepatocytes. However, little is known about possible roles that GDF15 might play in the regulation of iron homeostasis and development of hyperferritinemia in children with hemophagocytic lymphohistiocytosis (HLH). PROCEDURES: We compared serum GDF15 level and mRNA expressions of GDF15 and key molecules of iron metabolism, and made correlations between their expressions in children with HLH and control children. RESULTS: Serum GDF15 level was remarkably higher in HLH group than that in controls, with median serum concentration of 1,700 and 260 pg/ml, respectively (P < 0.001). In addition, GDF15 mRNA was significantly upregulated but independent of hypoxia-inducible factor-mediated oxygen signaling pathway. More importantly, GDF15 induction was positively correlated to upregulation of ferroportin, the only cellular iron exporter, and to upregulation of ferritin heavy chain. CONCLUSIONS: Our study suggests that GDF15 induction helps suppress further activation of macrophages in stressful physiologic states as HLH, and is intimately implicated in the development of hyperferritinemia by modulating the hepcidin-ferroportin axis, resulting in enhanced ferroportin-mediated iron efflux. Pediatr Blood Cancer © 2013 Wiley Periodicals, Inc.

Concepts: Regulation of gene expression, Iron deficiency anemia, Hematology, Ferroportin, Anemia of chronic disease, Hepcidin, Human iron metabolism, Gene expression

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Children presenting with medulloblastoma have a wide range of initial presenting symptoms. However, the influence of underlying tumor biology on the initial presentation of medulloblastoma is currently unknown. In light of the recent discovery of distinct medulloblastoma subgroups, we sought to define the initial presentation of childhood medulloblastoma in a subgroup specific manner.

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Despite intensive therapy, children with metastatic and recurrent sarcoma or neuroblastoma have a poor prognosis. Magnetic resonance guided high intensity focused ultrasound (MR-HIFU) is a noninvasive technique allowing the delivery of targeted ultrasound energy under MR imaging guidance. MR-HIFU may be used to ablate tumors without ionizing radiation or target chemotherapy using hyperthermia. Here, we evaluated the anatomic locations of tumors to assess the technical feasibility of MR-HIFU therapy for children with solid tumors.

Concepts: Ionizing radiation, Magnetic resonance imaging, Radiation, Radiation therapy, Medicine, Radiology, Oncology, Cancer

24

Constitutional mismatch repair deficiency (CMMRD) is a cancer predisposition syndrome associated with a high risk of developing early-onset malignancies of the blood, brain, and intestinal tract. We present the case of a patient with T-lymphoblastic lymphoma at the age of 3 years, followed by Burkitt lymphoma 10 years later. This patient also exhibited numerous nonmalignant findings including café au lait spots, lipomas, bilateral renal nodules, a nonossifying fibroma, multiple colonic adenomas, and a rapidly enlarging pilomatrixoma. The spectrum of malignant and nonmalignant neoplasms in this patient highlights the remarkable diversity, and early onset, of lesions seen in children with CMMRD.

Concepts: Anatomical pathology, Nonossifying fibroma, Fibroma, Benign tumor, Types of cancer, Cancer, Oncology, AIDS

23

Maffucci syndrome is a nonhereditary disorder caused by somatic mosaic isocitrate dehydrogenase 1 or 2 (IDH1 or IDH2) mutations and is characterized by multiple enchondromas along with hemangiomas. Malignant transformation of enchondromas to chondrosarcomas and secondary neoplasms, such as brain tumors or acute myeloid leukemia, are serious complications. A 15-year-old female with Maffucci syndrome developed B-cell precursor acute lymphoblastic leukemia (BCP-ALL). A somatic mutation in IDH1 was detected in hemangioma and leukemic cells. KRAS mutation and deletion of IKZF1 were detected in leukemic cells. Patients with Maffucci syndrome may, therefore, be at risk of BCP-ALL associated with secondary genetic events that affect lymphocyte differentiation.

Concepts: Ionizing radiation, Mutation, Acute myeloid leukemia, Genetics, Acute lymphoblastic leukemia, DNA, Leukemia, Cancer

23

An analysis of dose modifications for infants in 29 Children’s Oncology Group protocols across 10 cancer types revealed 11 sets of criteria defining the infant population using age, weight, body surface area (BSA), or a combination of these parameters and eight dose modification methods. A new method of dosing anticancer drugs in infants was developed based on the rationale that prior modifications were implemented to reduce toxicity, which is not cancer-specific. The new method uses BSA dose banding in dosing tables for infants and children with a BSA <0.6 m(2) and gradually transitions from body weight based to BSA-based dosing.

Concepts: Performance status, Body surface area, Metastasis, Experimental cancer treatment, Palliative care, Cancer, Oncology, Chemotherapy

22

Central venous catheter (CVC) dysfunction is a common complication among pediatric cancer patients. Tissue plasminogen activator (tPA) is administered to resolve CVC dysfunction. The present study was designed to determine risk factors associated with requirement of tPA for CVC dysfunction and to assess the clinical impact of CVC dysfunction in terms of CVC loss and venous thrombotic events (VTE).

Concepts: Stroke, Tissue plasminogen activator