[1] Univ Washington, Div Hematol, Seattle, WA 98195 USA
[2] Fred Hutchinson Canc Res Ctr, Ctr Stat, SW Oncol Grp, Seattle, WA 98104 USA
[3] Univ New Mexico, Canc Res & Treatment Ctr, Albuquerque, NM 87131 USA
[4] Fred Hutchinson Canc Res Ctr, Div Clin Res, Seattle, WA 98104 USA