[1] Baylor Coll Med, Dept Internal Med, Houston, TX 77030 USA
[2] Univ Texas MD Anderson Canc Ctr, Dept Pulm Med, Houston, TX 77030 USA
[3] Univ Texas MD Anderson Canc Ctr, Dept Pathol, Houston, TX 77030 USA
[4] Univ Texas MD Anderson Canc Ctr, Dept Hosp Med, Houston, TX 77030 USA