DISEASE CHARACTERISTICS:

• Histologically confirmed adenocarcinoma of the colon or rectum

  • Metastatic disease
  • Inoperable disease (i.e., not suitable for complete carcinological surgical resection)

• Measurable disease or nonmeasurable disease

  • At least 1 unidimensionally measurable lesion at least 20 mm by conventional CT scan OR 10 mm by spiral CT scan
  • Nonmeasurable disease defined as all other lesions, including small lesions or truly nonmeasurable disease
• No CNS metastases
• No exclusive bone metastases
• No symptomatic ascites or pleural effusion not evacuated before study entry

PATIENT CHARACTERISTICS:

Age

• 18 to 75

Performance status

• WHO 0-2

Life expectancy

• Not specified

Hematopoietic

• Neutrophil count at least 1,500/mm^3
• Platelet count at least 100,000/mm^3
• No known significant bleeding disorder

Hepatic

• Alkaline phosphatase less than 3 times upper limit of normal (ULN)

Renal

• Creatinine less than 1.5 times ULN OR
• Creatinine clearance at least 30 mL/min
• No uncontrolled hypercalcemia

Cardiovascular

• No congestive heart failure

Gastrointestinal

• No total or partial bowel obstruction
• No active gastric or duodenal ulceration or gastrointestinal bleeding within the past year
• No active inflammatory bowel disease

Other

• Not pregnant or nursing
• Fertile patients must use effective contraception
• HIV negative
• No peripheral sensory neuropathy
• No known sensitivity to celecoxib, other COX-2 inhibitors, NSAIDs, salicylates, or sulfonamides
• No AIDS-related illness
• No active infection
• No other malignancy within the past 5 years except adequately treated carcinoma in situ of the cervix or basal cell or squamous cell skin cancer
• No other severe acute or chronic medical or psychiatric condition or laboratory abnormality that would preclude study participation

PRIOR CONCURRENT THERAPY:

Biologic therapy

• No prior immunotherapy for metastatic disease

Chemotherapy

• Prior adjuvant chemotherapy allowed provided the progression-free interval after completion of therapy is more than 6 months in duration
• No prior chemotherapy for metastatic disease
• No prior adjuvant oxaliplatin
• No other concurrent chemotherapy

Endocrine therapy

• No concurrent chronic oral or IV corticosteroid use (i.e., 2 weeks or longer in duration)

Radiotherapy

• No concurrent radiotherapy

Surgery

• Not specified

Other

• More than 30 days since prior investigational drugs
• No other concurrent investigational drugs or treatments
• No concurrent prophylactic fluconazole

• No concurrent chronic full-dose aspirin (at least 325 mg/day), other nonsteroidal anti-inflammatory drugs (NSAIDs), or other cyclooxygenase (COX)-2 inhibitors

  • Concurrent low-dose (cardioprotective) aspirin (80 mg/day or equivalent) allowed
• No concurrent lithium
• No other concurrent anticancer therapy