[1] Univ Texas MD Anderson Canc Ctr, Houston, TX 77030 USA
[2] Allegheny Gen Hosp, Pittsburgh, PA 15212 USA
[3] Univ Texas MD Anderson Canc Ctr, Div Canc Med, Dept Thorac Head & Neck Med Oncol, Houston, TX 77030 USA
[4] Univ Texas MD Anderson Canc Ctr, Dept Thorac & Head & Neck Med Oncol, Houston, TX 77030 USA