Blood samples are obtained at baseline and periodically during study for pharmacokinetic studies. Tumor tissue samples are obtained by core biopsy at baseline for biomarker correlative studies. Samples are analyzed by IHC to measure expression and activation of EGFR-signaling pathway biomarkers in pretreatment esophageal tumor tissue, including EGFR and phosphorylated (p)-EGFR, ERK and p-ERK, Akt and p-Akt, p70s6k and p-p70s6k, and p27.