Clinical and molecular characteristics of pediatric gastrointestinal stromal tumors (GISTs)

Authors

  • Victoria E. Price,

    1. Department of Pediatrics, Division of Hematology/Oncology, The Hospital for Sick Children, University of Toronto, Toronto
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  • Maria Zielenska,

    1. Department of Pediatric Laboratory Medicine, Molecular Pathology, The Hospital for Sick Children, University of Toronto, Toronto
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  • Susan Chilton-MacNeill,

    1. Department of Pediatric Laboratory Medicine, Molecular Pathology, The Hospital for Sick Children, University of Toronto, Toronto
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  • Charles. R. Smith,

    1. Department of Pediatric Laboratory Medicine, Division of Pathology, The Hospital for Sick Children, University of Toronto, Toronto
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  • Alberto S. Pappo MD

    Corresponding author
    1. Department of Pediatrics, Division of Hematology/Oncology, The Hospital for Sick Children, University of Toronto, Toronto
    • Division Hematology/Oncology, The Hospital for Sick Children 555 University Ave., Toronto, M5G 1X8.
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  • Presented in part at the 40th annual meeting of the American Society of Clinical Oncology, June 5–8, 2004, New Orleans, LA.

Abstract

Background

To describe the clinical characteristics, molecular features, treatment, and outcome of six pediatric patients with gastrointestinal stromal tumors (GISTs).

Patients and Methods

Retrospective clinical review of GISTs, seen at The Hospital for Sick Children (HSC) Toronto, over an 11-year period. All specimens were stained for the CD 117 and CD 34 antigens. Three specimens were sequenced for mutations in exons 9, 11, and 13 of the c-kit gene.

Results

Five patients were evaluated and treated at HSC and one was referred for histopathological consultation only. The median patient age at diagnosis was 13.6 years, (6.9–14.8 years); four were female. All patients presented with anemia secondary to gastrointestinal (GI) bleeding. The disease was localized in five patients and two had other malignancies consistent with the diagnoses of Carney's triad. Immunohistochemical staining for CD 117 and CD 34 showed heavy cytoplasmic localization in all of the tumor cells. A novel point mutation of KIT in codon 456 of exon 9 was found in one case. Complete surgical resection was achieved in the five patients managed at our center and none received adjuvant therapies. Disease recurred locally in one patient. Four patients are alive and one is lost to follow-up.

Conclusions

In children and adolescents, GISTs should be considered in the differential diagnosis of anemia secondary to GI hemorrhage. The absence of an exon 11 mutation and the identification of a novel mutation in exon 9 suggest that pediatric GISTs may respond differently to currently available targeted therapies and therefore should be studied within the context of collaborative group trials. Pediatr Blood Cancer 2005; 45:20–24. © 2005 Wiley-Liss, Inc.

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