Gene Expression Profiles to Categorize Wilms Tumors

OBJECTIVES:

I. Identify new molecular categories of Wilms tumor (WT) based on the gene expression
profiles of samples from patients with this disease.

II. Develop a classifying system (classifier) that will predict a defined number of
clinically relevant categories based on expression of an established set of genes.

III. Confirm and test the classifier with further analysis of the genes by several different
methodologies, using additional patient samples that are outside of the case/cohort but
which possess the clinically or scientifically relevant parameter.

IV. Validate the use of the classifier to predict defined groups within a second set of
samples (for which investigators are blinded to the clinical and biological data) by
subsequent comparison with true incidence of pertinent markers.

OUTLINE:

Three hundred tumor specimens are analyzed for genetic expression profiles using Affymetrix
assays. Specific genes are identified as classifiers and analyzed using tissue arrays. An
additional 300 specimens are examined for gene expression and categorized according to the
classifiers.

Inclusion Criteria:

- Specimens from patients previously enrolled as "On Study" or "Followed Biology Only"
on protocol NWTSG-5 (COG-Q9401)

- Study follow-up data for disease status available

- National Wilms Tumor Study Group/Children's Oncology Group pathology review showing
"favorable" histology

- Sufficient biology samples available without using biology bank reserves