[1] Univ Virginia, Inova Schar Canc Inst, Fairfax, VA USA
[2] SWOG Stat Ctr, Fred Hutchinson Canc Res Ctr, Seattle, WA USA
[3] Cedars Sinai Med Ctr, Los Angeles, CA USA
[4] Univ Texas MD Anderson Canc Ctr, Dept Thorac Head & Neck Med Oncol, Houston, TX USA
[5] Univ Texas MD Anderson Canc Ctr, Houston, TX USA
[6] SWOG Stat & Data Management Ctr, Fred Hutchinson Canc Ctr, Seattle, WA USA
[7] Levine Canc Inst, Charlotte, NC USA
[8] Univ Texas MD Anderson Canc Ctr, Dept Pathol, Houston, TX USA
[9] Wake Forest Coll, Winston Salem, NC USA
[10] Missouri Baptist Med Ctr, St Loius, MO USA
[11] Southern Illinois Univ, Springfield, IL USA
[12] Southeastern Med Oncol Ctr, Goldsboro, NC USA
[13] Minnesota Oncol Hematol, Coon Rapids, MN USA
[14] Univ New Mexico Comprehens Canc Ctr, Albuquerque, NM USA
[15] Billings Clin, Billings, MT USA
[16] St Lukes Canc Inst, Boise, ID USA
[17] H Lee Moffitt Canc Ctr & Res Inst, Tampa, FL USA
[18] UC Davis Comprehens Canc Ctr, Sacramento, CA USA