Patients undergo tumor tissue biopsies at baseline and after the first dose of cetuximab for correlative laboratory studies. Samples are analyzed for proliferation (Ki-67 labeling index), microvessel density (CD-31 staining), apoptosis (TUNEL assay and caspase-3 by IHC) signaling pathway (expression of EGFR, AKT, and MAPK by IHC), molecules affecting FDG uptake (expression of GLUT1, GLUT3, and hexokinase by IHC), and thymidine kinase 1 activity or expression.