S9304A Study of Protein Expression in Tumor Tissue Samples From Patients With Stage II or Stage III Rectal Cancer Enrolled in Clinical Trial SWOG-9304

OBJECTIVES: * Determine expression levels of thioredoxin-1 (Trx-1), thioredoxin-interacting protein (TXNIP), and hypoxia inducible factor-1 alpha (HIF-1α) in paraffin-embedded resected tumor tissue samples from patients with stage II or III rectal cancer enrolled in clinical trial SWOG-9304. * Determine if there is a correlation between Trx-1 and TXNIP expression and HIF-1α expression. * Correlate expression of these proteins with tumor stage, disease-free survival, overall survival, and risk of recurrence. * Determine interactions for patient age, performance status, and type of therapy received on clinical trial SWOG-9304. OUTLINE: This is a multicenter study. Paraffin-embedded resected tumor tissue samples are analyzed for protein expression levels (thioredoxin-1, thioredoxin-interacting protein, and hypoxia inducible factor-1 alpha) by tissue microarray and immunostaining.