A Single Arm Trial of Oxaliplatin and 5FU With Concurrent Radiation in Patients With Metastatic Rectal Cancer

Inclusion Criteria: 1. Patients with previously untreated and pathologically proven adenocarcinoma of the rectum with distant metastasis who would benefit from combined local therapy and systemic chemotherapy. 2. Lower border of tumour must be within 15cm of anal verge. 3. Age \>= 18 years. 4. ECOG Performance Status 0-2 5. Absolute Neutrophil Count \> 1.5x10\^9/L, haemoglobin \> 100 g/L, and platelets \> 100x10\^9/L. 6. Renal: Creatinine clearance \>= 55 mL/min (using radioisotope renal scan or derived from serum creatinine using the Cockcroft-Gault formula). 7. Bilirubin \<= 2.0 x upper limit of normal. 8. ALT \<= 5 x upper limit of normal 9. Life expectancy in excess of 3 months. 10. No symptomatic peripheral neuropathy \> grade 2. 11. Males or non-pregnant, non-lactating females. Female patients of child-bearing potential, not surgically sterilized, must use an adequate form of contraception (oral contraceptive pill or barrier method). 12. Signed informed consent Exclusion Criteria: 1. Prior pelvic radiotherapy 2. Febrile intercurrent illness or infection. 3. History of myocardial infarction within the previous six months or unstable cardiac disease or any other medical condition likely to compromise the safe delivery of chemotherapy or radiotherapy. 4. Concurrent treatment with other anti-cancer therapy. 5. Significant medical conditions which in the opinion of the investigator would compromise the planned delivery of the chemotherapy and radiotherapy or which may be potentially exacerbated by these modalities. 6. Locally recurrent rectal cancer