1. The University of Texas MD Anderson Cancer Center, Houston, TX
2. ACOSOG Statistical Center, Mayo Clinic, Rochester, MN
3. Simmons Cancer Center, The University of Texas Southwestern Medical Center, Dallas, TX
4. Siteman Cancer Center, Washington University School of Medicine, St. Louis, MO
5. Mayo Clinic, Rochester, MN
6. Doctors Hospital of Laredo, Laredo, TX
7. University of New Mexico Cancer Center, Albuquerque, NM