Celecoxib Combined With Fluorouracil and Leucovorin in Treating Patients With Resected Stage III Adenocarcinoma (Cancer) of the Colon

DISEASE CHARACTERISTICS: Histologically confirmed adenocarcinoma of the colon 15 cm above anal verge Stage III disease (any pT, N1-2, M0) No rectal cancer Must have undergone curative radical resection (R0 resection) within the past 6 weeks PATIENT CHARACTERISTICS: Age 18 and over Performance status WHO 0-1 Life expectancy Not specified Hematopoietic Absolute neutrophil count ≥ 1,500/mm^3 Platelet count ≥ 100,000/mm^3 Hepatic AST ≤ 5 times upper limit of normal (ULN) Bilirubin ≤ 1.5 times ULN Renal Creatinine ≤ 1.5 times ULN Cardiovascular None of the following conditions within the past 6 months: Myocardial infarction Unstable angina Symptomatic congestive heart failure Serious uncontrolled cardiac arrhythmia Cerebrovascular accident or transient ischemic attack Deep vein thrombosis Other significant thromboembolic event Pulmonary No pulmonary embolism within the past 6 months Gastrointestinal No active gastric or duodenal ulceration within the past year No gastrointestinal bleeding within the past year No partial or complete bowel obstruction No known chronic malabsorption No active inflammatory bowel disease or chronic diarrhea (more than 4 stools/day) Other Not pregnant or nursing Fertile patients must use effective contraception HIV negative No AIDS-related illness No prior hypersensitivity to fluorouracil, leucovorin calcium, celecoxib, other COX-2 inhibitors, NSAIDs, salicylates, or sulfonamides No other severe acute or chronic medical condition or laboratory abnormality that would preclude study participation, study drug administration, or study results interpretation No psychological, familial, sociological, or geographical condition that would preclude study compliance No concurrent 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 PRIOR CONCURRENT THERAPY: Biologic therapy No concurrent sargramostim (GM-CSF) or molgramostim Chemotherapy Not specified Endocrine therapy No more than 4 weeks of concurrent orally/nasally inhaled steroids over a 6-month period Concurrent mometasone (or fluticasone) allowed if patients require ≥ 4 weeks of inhaled steroid therapy At least 30 days since other prior steroids No concurrent hormonal therapy Radiotherapy No concurrent radiotherapy Surgery See Disease Characteristics No prior total colectomy or other major surgery that would result in substantial alteration in transit to absorption of oral medication Other More than 30 days since prior investigational medication No prior systemic anticancer treatment for colon cancer No concurrent prophylactic fluconazole No concurrent lithium No concurrent chronic* use of full dose aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs), or cyclo-oxygenase-2 (COX-2) inhibitors Aspirin at cardioprotective doses (i.e., 80 mg daily or equivalent) allowed No concurrent participation in any other clinical study No other concurrent experimental agents (e.g., other COX-2 inhibitors, matrix metalloproteinase inhibitors, inhibitors of the vascular endothelial growth factor/Flk-1 pathway, or inhibitors of the epidermal growth factor receptor pathway) NOTE: *Chronic use is defined as a frequency of 7 consecutive days (1 week) for more than 3 weeks/year or more than 21 days throughout the year