[1] NCI, Div Canc Epidemiol & Genet, NIH, Bethesda, MD 20852 USA
[2] McGill Univ, Jewish Gen Hosp, Dept Oncol, Montreal, PQ H3T 1E2, Canada
[3] McGill Univ, Montreal, PQ H3T 1E2, Canada
[4] Informat Management Serv Inc, Silver Spring, MD 20904 USA
[5] Natl Inst Hlth & Welf, Dept Chron Dis Prevent, FI-00300 Helsinki, Finland