[1] Univ Aberdeen, Dept Publ Hlth, Aberdeen AB9 1FX, Scotland
[2] Natl Canc Registry Ireland, Cork, Ireland
[3] Univ Hosp NHS Trust, Queens Med Ctr, Histopathol Dept, Nottingham, England
[4] Univ Ottawa, Dept Epidemiol & Community Med, Canada Res Chair Human Genome Epidemiol, Ottawa, ON K1N 6N5, Canada
[5] Univ Aberdeen, Dept Obstet & Gynaecol, Aberdeen AB9 1FX, Scotland
[6] Univ Nottingham, Sch Med, Sch Community Hlth Sci, Div Epidemiol & Publ Hlth, Nottingham NG7 2RD, England