[1] Univ Dundee, Ninewells Hosp & Med Sch, Div Populat Hlth & Genom, Dundee, Scotland
[2] Bowel Canc UK, Edinburgh, Scotland
[3] Royal Alexandra Hosp, Dept Surg, Paisley, Scotland
[4] Univ Dundee, Ninewells Hosp Med Sch, Div Populat Hlth & Genom, Dundee DD1 9SY, Scotland