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

Preoperative induction chemotherapy has been successfully used in a variety of malignancies and provides several advantages over postoperative therapy. Combination of 5-FU/Leucovorin/CPT-11 has demonstrated significantly better response rate than 5-FU/Leucovorin alone. Replacing 5-FU with oral capecitabine in combination with CPT-11 has emerged as a potentially more effective, safe and convenient treatment option for metastatic colorectal cancer. Capecitabine is also well tolerated in concurrent treatment with radiation. Recent data has shown that preoperative radiation appears to be significantly more effective in increasing resectability rates. This trial will investigate the activity of capecitabine and CPT-11 combination in the preoperative setting followed by chemoradiation with capecitabine in locally advanced rectal cancer to improve response and decrease local recurrence. We will also study whether TS, TP, DPD and carboxyesterase expressions correlate with the objective response rate with this chemotherapy and chemoradiation regimen.

OUTLINE: This is a multi-center study. 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\* For calculated creatinine clearance of 30-50 mL/min or patients \> 70years old, capecitabine starting dose is 825 mg/m2 PO BID Beginning at week 7 or following recovery from chemotherapy: * 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 * Capecitabine 825\* mg/m2 PO BID, 5 days/week, throughout XRT\* For calculated creatinine clearance of 30-50 mL/min or patients \> 70years old, capecitabine starting dose is 650 mg/m2 PO BID * Surgery within 8weeks following chemoradiotherapy * Adjuvant Chemotherapy at investigator's discretion ECOG performance status 0 or 1 Hematopoietic:· * ANC count \>1,500 mm3· * Platelets \> 100,000/mm3· * Hemoglobin \> 9g/dL * Prothrombin time (PT)/INR or PTT \< 1.25 times upper limit of normal; Hepatic:· * Bilirubin \<1.5 times upper limit of normal * Alanine Transaminase (ALT) or Aspartate Transaminase (AST) \<2.5 times the upper limit of normal Renal:· * Adequate renal function by calculated creatinine clearance \> 30 mL/min (by Cockroft and Gault) Cardiovascular:· * No congestive heart failure requiring therapy or NYHA class II or greater or active angina or known myocardial infarction within 12 months prior to study