[1] Univ Miami, Miller Sch Med, Sylvester Comprehens Canc Ctr, Dept Med, Miami, FL 33136 USA
[2] Univ Miami, Miller Sch Med, Sylvester Comprehens Canc Ctr, Dept Radiat Oncol, Miami, FL 33136 USA
[3] Univ Texas MD Anderson Canc Ctr, Dept Gastrointestinal Med Oncol, Houston, TX 77030 USA