Celecoxib in Preventing Hand/Foot Syndrome Caused By Capecitabine With Metastatic Breast or Colorectal Cancer

OBJECTIVES: * Determine the efficacy of celecoxib in reducing the incidence and severity of hand/foot syndrome caused by capecitabine in patients with metastatic breast cancer or colorectal cancer. OUTLINE: This is a placebo-controlled, randomized, double-blind, multicenter study. Patients are stratified according to metastatic disease (breast vs colorectal), ECOG performance status (0 or 1 vs 2), prior chemotherapy (yes vs no). Patients receive 1 of 2 treatment regimens. * Regimen A (concurrent radiotherapy): Patients undergo radiotherapy 5 days a week for 5-6 weeks and receive oral capecitabine twice daily 5 days a week. Following completion of radiotherapy, patients may continue oral capecitabine as in regimen B. * Regimen B (no radiotherapy): Patients receive oral capecitabine once daily on days 1-14. Courses repeat every 21 days. Patients are also randomized to 1 of 2 treatment arms. * Arm I: Patients receive oral celecoxib twice daily on days 1-21. * Arm II: Patients receive oral placebo twice daily on days 1-21. In both arms, treatment repeats every 21 days in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed every 3 months. PROJECTED ACCRUAL: A total of 342 patients will be accrued for this study.