[1] Baylor Coll Med, Dept Med, Sect Gastroenterol & Hepatol, Houston, TX 77030 USA
[2] Baylor Coll Med, Dept Med, Houston, TX 77030 USA
[3] Michael E DeBakey VA Med Ctr, Houston VA HSR & Ctr Innovat Qual Effectiveness &, Houston, TX USA
[4] MD Anderson Canc Ctr, Gastroenterol Hepatol & Nutr Dept, Houston, TX USA
[5] Baylor Coll Med, Dept Pathol & Immunol, Houston, TX USA
[6] Baylor Coll Med, Dept Med, Sect Epidemiol & Populat Sci, Houston, TX USA
[7] Baylor Coll Med, Dan L Duncan Comprehens Canc Ctr, Houston, TX USA