[1] Sunnybrook Hlth Sci Ctr, Toronto, ON M4N 3M5, Canada
[2] Cross Canc Inst, Edmonton, AB T6G 1Z2, Canada
[3] QEII Hlth Sci Ctr, Halifax, NS, Canada
[4] Fraser Valley Ctr, BC Canc Ctr, Surrey, BC, Canada
[5] NCIC Clin Trials Grp, Kingston, ON, Canada
[6] NCI, Rockville, MD USA
[7] Univ Toronto, Princess Margaret Hosp, Univ Hlth Network, Dept Med Oncol & Hematol, Toronto, ON, Canada