Chemotherapy With or Without Surgery in Treating Patients With Metastatic Colorectal Cancer That Cannot Be Removed by Surgery

DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed colorectal cancer

  • Metastases which are unresectable at presentation
• No known unresectable primary tumor on CT/MRI scan

• Primary tumor does not require immediate or emergency intervention including surgery, radiotherapy, laser, or stenting

  • Patients who are treated with colonic stents are eligible
• No unequivocal extensive peritoneal metastases

PATIENT CHARACTERISTICS:

• WHO performance status 0-1
• Must be fit for systemic chemotherapy and surgery
• Hemoglobin > 10.0 g/dL
• WBC > 3.0 x 10^9/L
• Platelet count > 100 x 10^9/L
• Bilirubin < 25 μmol/L
• GFR > 50 mL/min
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception during and for 3 months (female) or up to 2 months (male) after completion of study therapy
• No history of malignant disease within the past 5 years except for nonmelanomatous skin cancer or carcinoma in situ of the cervix
• No serious medical co-morbidity (e.g., uncontrolled inflammatory bowel disease, uncontrolled angina, recent [within the past 6 months] myocardial infarction, or another serious medical condition) judged to compromise ability to tolerate chemotherapy and/or surgery

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics
• Concurrent participation in a trial of chemotherapy, if eligible, allowed
• Concurrent short-course radiotherapy for operable rectal cancer allowed