[1] Univ Massachusetts, Sch Med, Div Gastroenterol, Dept Med, Worcester, MA 01635 USA
[2] Univ Massachusetts, Sch Med, Dept Canc Biol, Worcester, MA 01635 USA
[3] Univ Massachusetts, Sch Med, Div Oncol, Worcester, MA 01635 USA
[4] UMassMem Hlth Care, Div Anat Pathol, Dept Pathol, Worcester, MA USA
[5] Malmo Univ Hosp, Dept Ophthalmol, Malmo, Sweden
[6] Norwegian Univ Sci & Technol, Dept Canc Res & Mol Med, N-7034 Trondheim, Norway
[7] Columbia Univ, Sch Med, Div Digest Dis, Dept Med, New York, NY USA