[1] Queens Univ, Canc Res Inst, Div Canc Care & Epidemiol, Kingston, ON K7L 3N6, Canada
[2] Queens Univ, Dept Oncol, Kingston, ON K7L 3N6, Canada
[3] Queens Univ, Canc Ctr Southeastern Ontario, Kingston, ON K7L 3N6, Canada
[4] Univ Toronto, Dept Family & Community Med, Ontario Inst Canc Res, Toronto, ON M5S 1A1, Canada
[5] Ottawa Hosp, Ctr Canc, Ottawa, ON, Canada
[6] BC Canc Agcy, Vancouver, BC, Canada