[1] Royal North Shore Hosp, Upper GI Surg Unit, Sydney, NSW, Australia
[2] Univ Sydney, Sydney Med Sch, Sydney, NSW, Australia
[3] Royal North Shore Hosp, Kolling Inst Med Res, Canc Diag & Pathol Grp, Sydney, NSW, Australia
[4] Royal North Shore Hosp, Dept Anat Pathol, Sydney, NSW, Australia