Study of Tumor Samples From Patients With Ewing Sarcoma

Study Overview
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Brief Summary
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This laboratory study is looking at tumor samples from patients with Ewing sarcoma. Studying samples of tumor tissue from patients with cancer in the laboratory may help doctors learn more about changes that occur in DNA and identify biomarkers related to cancer

Detailed Description
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Study Subtype: Ancillary/Correlative Observational Study Model: Cohort Time Perspective: Prospective Biospecimen Retention: Samples With DNA Biospecimen Description: Tissue Study Population Description: Samples collected from AEWS0031 and patients registered on AEWS08B1 Sampling Method: Non-Probability Sample PRIMARY OBJECTIVES: I. Determine if mutation of p53, and/or deletion of the p16 locus, have prognostic value in patients with Ewing sarcoma. SECONDARY OBJECTIVES: I. Estimate the incidence of p53 mutation in Ewing sarcoma samples collected from COG studies. II. Estimate the incidence of p16 deletions in Ewing sarcoma samples collected from COG studies. III. Prepare and archive amplified genomic DNA from Ewing sarcoma samples collected from COG studies for future biologic analysis. OUTLINE: This is a multicenter study. Previously archived tumor samples are analyzed for p53 mutations and p16 deletion by immunohistochemistry, FISH, PCR, and DNA sequencing.

Official Title
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Observational - Prognostic Value of p53 and/or p16 Alterations in Ewing Sarcoma

Conditions
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Localized Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor

Intervention / Treatment
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* Other: laboratory biomarker analysis


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Diagnosis of Ewing sarcoma Banked specimens from patients enrolled on AEWS0031

Ages Eligible for Study
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Maximum Age: 50 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Correlative studies<br>Previously archived tumor samples are analyzed for p53 mutations and p16 deletion by immunohistochemistry, FISH, PCR, and DNA sequencing. | Other: laboratory biomarker analysis<br>* Correlative studies<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Event-free survival |  | Time from study entry until disease progression, death without progression of disease, occurrence of a second malignant neoplasm or last follow-up, assessed up to 3 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of p53 mutations using the model of Sather and Sposto | Assessed using a two sided log rank test. The expected 95% confidence interval associated with this estimate, as a function of sample size and true mutation/deletion frequency is provided. | Baseline | 
| Incidence of p16 loss or deletion using the model of Sather and Sposto | Assessed using a two sided log rank test. The expected 95% confidence interval associated with this estimate, as a function of sample size and true mutation/deletion frequency is provided. | Baseline |