Re-eval of patient population

This study will assess the complete clinical response (no clinical evidence of remaining disease or recurrence of disease)in rectal cancer that arises within 3 inches of the anal opening after radiation therapy given at the same time as chemotherapy over a 6 week period, followed by chemotherapy alone given three times over an additional 9 weeks. Follow-up begins with an examination at the end of treatment (at 15 weeks), with ongoing follow-up every 4-6 weeks for one year.

Research has shown that low rectal cancer treated with neoadjuvant chemoradiation (54Gy concurrent with 3 cycles of 5-FU/Leucovorin) followed by 3 additional cycles of 5FU/Leucovorin, followed by close follow-up (every 4-6 weeks for one year)has had good success in achieving complete clinical response, avoiding surgical intervention. If at follow-up remaining disease is found or if there is recurrent disease, surgery can be performed.

Inclusion Criteria:

• over 18 years old
• tumor potentially resectable en bloc; tumors tethered or fixed to a structure that can be removed
• clinical/radiological stages T2,T3,or T4, N0-1
• ANC >1500, PLT>100,000
• AST and alkaline phosphatase < 2.5 X ULN
• bilirubin < 1.5 X ULN
• CrCl > 50 ml/min using Cockcroft-Gault formula
• KPS >60
• ECOG Performance Scale 0-2
• No malignancies within previous 5 years other than non-melanoma skin cancer, in-situ cervical cancer, in-situ ductal breast cancer
• no evidence of metastatic disease

Exclusion Criteria:

• initial tumor fixation to pelvic bone or side wide; technically unresectable disease
• any evidence of distant metastasis
• perforation
• obstruction
• hereditary non-polyposis colorectal cancer
• synchronous primary colon carcinomas except T1 lesions
• known dihydropyrimidine dehydrogenase deficiency
• prior radiation therapy to the pelvis
• prior chemotherapy for malignancies
• known existing uncontrolled coagulopathy
• pregnancy or lactation
• women of childbearing potential not using reliable and appropriate contraceptive method
• serious, uncontrolled concurrent infection(s)
• participation in any investigational drug study within 4 weeks preceding the start of study treatment
• clinically significant heart disease
• other serious uncontrolled medical conditions that might compromise study participation (in the investigator's opinion)
• major surgery within 4 weeks prior to the study treatment
• lack of physical integrity of the upper GI tract or malabsorption syndrome