Shaker Abdullah

Publications (3)9.84 Total impact

• Article: Advances in the management of pediatric central nervous system tumors.

  Shaker Abdullah, Ibrahim Qaddoumi, Eric Bouffet
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  ABSTRACT: Central nervous system tumors are the most common pediatric solid tumors and a leading cause of cancer-related mortality and morbidity in this age group. Survival rates have improved significantly over the last decades for most of the tumor types, as a consequence of improvements in neuroimaging, neurosurgery and neuroanesthesia, radiation oncology, and medical oncology. The complexity of the management of these patients requires a multidisciplinary approach and has led to the emergence of a new subspecialty of pediatric neuro-oncologists who are dedicated to the management and follow-up of this population. This review highlights the most critical advances in the diagnostic and treatment modalities of pediatric brain tumors. A specific review of the most common tumor types discusses treatment options, controversies, and ongoing developments, with an emphasis on cooperative trials.
  Annals of the New York Academy of Sciences 10/2008; 1138:22-31. · 3.15 Impact Factor
• Article: Sevelamer hydrochloride: a novel treatment of hyperphosphatemia associated with tumor lysis syndrome in children.

  Shaker Abdullah, Manuel Diezi, Lillian Sung, L Lee Dupuis, Denis Geary, Oussama Abla
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  ABSTRACT: Sevelamer is a phosphate-binder used effectively for the treatment of hyperphosphatemia in patients treated with dialysis. To describe the safety of sevelamer in children with hyperphosphatemia secondary to tumor lysis syndrome and the serum phosphate concentrations observed following its administration. A retrospective chart review of all children with leukemia/lymphoma diagnosed between November 2002 and April 2004 who received sevelamer during their initial admission was conducted. We monitored the effects of sevelamer on serum phosphate concentration, calcium/phosphate product and renal function at hours 24, 48, and 72 from sevelamer initiation. Thirteen patients received sevelamer during the study period. Their median age was 13 years (range 2.7-17.9) and eight were boys. Nine children had acute lymphoblastic leukemia, one had acute myeloid leukemia and 3 had non-Hodgkin's lymphoma. The most frequently used dose of sevelamer was 400 mg orally twice daily. The median duration of sevelamer therapy was 2 days (range 1-7). Two children were excluded from the efficacy analysis due to concurrent use of dialysis. Mean serum phosphate levels decreased after sevelamer administration, in eleven patients, from a baseline 2.2 mmol/L +/- 0.4 (95% CI, 1.7-3.1) to 1.1 mmol/L +/- 0.2 at hour 72 (95%CI, 0.6-1.5). The only toxicity attributed to sevelamer was mild vomiting in three patients. Sevelamer appears to be effective and tolerable for the treatment of hyperphosphatemia associated with tumor lysis syndrome.
  Pediatric Blood & Cancer 08/2008; 51(1):59-61. · 1.89 Impact Factor
• Article: Expression of MYCN in pediatric synovial sarcoma.

  Gino R Somers, Maria Zielenska, Shaker Abdullah, Christopher Sherman, Suzanne Chan, Paul S Thorner
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  ABSTRACT: Synovial sarcoma accounts for between 6 and 10% of childhood sarcomas and histological diagnosis can be challenging, even for experienced pathologists. Several other tumors enter the differential diagnosis, including malignant peripheral nerve sheath tumor, Ewing sarcoma/primitive neuroectodermal tumor and undifferentiated sarcoma. Several recent reports utilizing expression array techniques have documented expression of the MYCN oncogene in synovial sarcoma. In order to more fully investigate this finding, a series of 12 synovial sarcomas and 29 other sarcomas (four malignant peripheral nerve sheath tumors, 15 Ewing sarcoma/primitive neuroectodermal tumors, 10 undifferentiated sarcomas) were examined for MYCN expression and gene amplification. By RT-PCR, nine of 12 synovial sarcomas (75%) expressed MYCN. Five synovial sarcomas (42%) expressed MYCN at high levels. Of the other sarcomas, one malignant peripheral nerve sheath tumor (25%) and five Ewing sarcoma/primitive neuroectodermal tumors (33%) expressed MYCN at low levels, and all other cases were negative for MYCN. None of the synovial sarcomas had genomic amplification, suggesting that high MYCN expression levels resulted from epigenetic phenomena. Examination of selected downstream targets of MYCN in synovial sarcoma revealed expression of MCM7 (minichromosome maintenance protein 7) in all synovial sarcomas, and expression of nestin (n=10; 83%), ID2 (inhibitor of DNA binding protein 2) (n=6; 50%) and MRP1 (multidrug resistance protein 1) (n=1; 8%) in a subset of synovial sarcomas. Expression of downstream targets did not correlate with expression of MYCN. Neither MYCN nor expression of downstream targets significantly correlated with metastases at presentation, progression-free survival or overall survival in this small series. In summary, high levels of MYCN expression was useful for distinguishing synovial sarcoma from other childhood-spindled cell sarcomas with specificity and sensitivity of 100 and 42%, respectively, in this series. The clinical and biological significance of this finding deserves further study.
  Modern Pathology 08/2007; 20(7):734-41. · 4.79 Impact Factor