Capecitabine + Irinotecan Followed by Combined Modality Capecitabine and Radiation in Locally Advanced Rectal Cancer

"Capecitabine 1000\* mg/m2 po bid day 1-14; repeat every three weeks for two cycles~\*For calculated creatinine clearance of 30-50 mL/min or patients \> 70 years old, capecitabine starting dose is 825 mg/m2 po bid"

Irinotecan 200 mg/m2 IV, day 1

biopsy per EUS

"* Irinotecan 200 mg/m2 IV, day 1~* Capecitabine 1000 mg/m2 po bid day 1-14; repeat every three weeks for two cycles"

Pelvic XRT 45 Gy/1.8 GY/fx/qd+5/4 Gy/1.8 Gy/fx/qd for T3+9 Gy/1.8/Gy/fx/qd for T4

Surgery within 8 weeks following chemoradiotherapy

Adjuvant chemotherapy at investigator's discretion