[1] Otto Von Guericke Univ, Dept Gastroenterol Hepatol & Infect Dis, Magdeburg, Germany
[2] Baylor Univ, Med Ctr, Baylor Res Inst, Gastrointestinal Canc Res Lab,Div Gastroenterol, Dallas, TX USA
[3] Baylor Univ, Med Ctr, Charles A Sammons Canc Ctr, Dallas, TX USA