[1] Univ Texas MD Anderson Canc Ctr, Dept Gastrointestinal Med Oncol, Houston, TX 77030 USA
[2] Anal Grp Inc, 111 Huntington Ave,14th Floor, Boston, MA 02199 USA
[3] Northwestern Univ, Feinberg Sch Med, Dept Med Social Sci, Chicago, IL 60611 USA
[4] Terasaki Res Inst, Los Angeles, CA USA
[5] Novartis Pharmaceut, E Hanover, NJ USA