[1] Univ N Carolina, Div Hematol Oncol, N Cent Canc Treatment Grp, Chapel Hill, NC 27599 USA
[2] Univ N Carolina, Div Med Oncol, Chapel Hill, NC USA
[3] Mayo Clin, Div Biostat, N Cent Canc Treatment Grp, Rochester, MN USA
[4] Iowa Oncol Res Assoc, Community Clin Oncol Program, N Cent Canc Treatment Grp, Des Moines, IA USA
[5] Dana Farber Canc Inst, Dept Oncol, Canc & Acute Leukemia Grp B, Boston, MA 02115 USA
[6] Univ Pittsburgh, Inst Canc, Div Med Oncol, Eastern Cooperat Oncol Grp, Pittsburgh, PA USA
[7] Univ Kansas, Med Ctr, Div Hematol & Oncol, SW Oncol Grp, Kansas City, KS 66103 USA
[8] Natl Canc Inst Canada, St Catharines, ON, Canada