 - Arm I: Patients receive panitumumab IV over 30-90 minutes on days 1, 15, 29, 43, and 57 and oral capecitabine twice daily on days 8-40. Beginning on day 8, patients undergo daily fractions of 3-D conformal radiotherapy 5 days a week for 5 weeks. Beginning approximately 6 weeks after completion of panitumumab and chemoradiotherapy, patients undergo surgery. 