[1] McGill Univ, Dept Oncol, Montreal, PQ H2W 1S6, Canada
[2] Nunavut Dept Hlth, Hlth Protect Unit, Iqaluit, NU, Canada
[3] McGill Univ, Dept Epidemiol, Montreal, PQ H2W 1S6, Canada
[4] McGill Univ, Dept Pathol, Montreal, PQ H2W 1S6, Canada
[5] McGill Univ, Dept Obstet & Gynecol, Montreal, PQ H2W 1S6, Canada
[6] Queens Univ, Dept Community Hlth & Epidemiol, Kingston, ON, Canada
[7] Hlth Canada, Populat & Publ Hlth Branch, Ctr Chron Dis Prevent & Control, Canc Bur,Environm Risk Assessment & Case Surveill, Ottawa, ON K1A 0L2, Canada