Radiation Therapy and Capecitabine With or Without Oxaliplatin in Treating Patients Who Are Undergoing Surgery for Stage II or Stage III Rectal Cancer

You may be eligible if

• DISEASE CHARACTERISTICS:
• Histologically confirmed adenocarcinoma of the rectum
• * T3-4, N0-2, M0 disease by endorectal ultrasound
• * T2 disease located in the low rectum allowed provided lower pole is ≤ 6 cm from the anal verge
• Tumor must be accessible to digital rectal examination (i.e., tumor located at low- or mid-rectum)
• Resectable disease treatable with chemoradiotherapy
• * No unresectable disease (i.e., T4 disease with high risk for incomplete gross resection \[i.e., R2\])
• PATIENT CHARACTERISTICS:
• Age
• 18 to 80
• Performance status
• ECOG 0-2
• Life expectancy
• Not specified
• Hematopoietic
• WBC ≥ 1,500/mm\^3
• Platelet count ≥ 100,000/mm\^3
• Hemoglobin \> 10 g/dL
• Hepatic
• Alkaline phosphatase normal
• Bilirubin normal
• Renal
• Creatinine ≤ 130 μmol/L
• No severe renal insufficiency
• Cardiovascular
• No cardiac insufficiency
• No symptomatic coronary artery disease
• Other
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception
• No contraindication to study treatment
• Prior acute intestinal obstruction allowed provided patient underwent surgical diversion with stoma
• No history of other cancer except basal cell skin cancer or carcinoma in situ of the cervix
• No peripheral neuropathy
• No uncontrolled diabetes
• No other uncontrolled severe disease
• No geographical, social, or psychological condition that would preclude study follow-up
• PRIOR CONCURRENT THERAPY:
• Biologic therapy
• Not specified
• Chemotherapy
• No prior chemotherapy for cancer
• No other concurrent chemotherapy
• Endocrine therapy
• Not specified
• Radiotherapy
• No prior radiotherapy for cancer
• Surgery
• Not specified
• Other
• No concurrent phenytoin
• No concurrent participation in another clinical trial of an experimental medical treatment