[1] McGill Univ, Dept Expt Med, Montreal, PQ, Canada
[2] McGill Univ, Dept Oncol, Montreal, PQ, Canada
[3] McGill Univ, Jewish Gen Hosp, Lady Davis Inst, Ctr Clin Epidemiol, Montreal, PQ H3T 1E2, Canada
[4] McGill Univ, Jewish Gen Hosp, Lady Davis Inst Med Res, Montreal, PQ H3T 1E2, Canada