Phase III Randomized Trial of 5-FU/Leucovorin/Levamisole Versus 5-FU Continuous Infusion/Levamisole as Adjuvant Therapy for High-Risk Resectable Colon Cancer

Inclusion Criteria

DISEASE CHARACTERISTICS: Histologically proven resectable stage II or III adenocarcinoma
of the colon Caudal margin of the primary tumor must lie above the peritoneal reflection
Must have pathologic confirmation of either N1-3 (stage III), or if N0, must have T3-T4
(stage II) with bowel obstruction or perforation Obstruction documented as: At least 75%
colon or small bowel obstruction on x-ray and/or endoscopy Significant bowel dilatation
surgically documented Significant obstruction described in the pathology report
Perforation documented by gross operative/pathologic evidence of a colon wall defect with
associated abscess or peritonitis Complete en bloc resection by laparotomy required No
laparoscopic colectomy without prior surgery on protocol SWOG-9411 No gross or microscopic
residual disease No distant peritoneal metastases (stage IV) even if grossly resectable No
requirement to open the pelvic peritoneum to define the extent of disease No extrapelvic
nodal metastasis unless resected en bloc with the primary tumor No distant metastases No
other diagnosis of stage II-III colon cancer within the past 5 years May have undergone
complete surgical resection at least 5 years prior to study Completely resected prior or
synchronous stage 0-I colon cancer eligible

PATIENT CHARACTERISTICS: Age: Adult Performance status: SWOG 0-2 Hematopoietic: WBC (white
blood cell) at least 3,500/mm3 Platelet count at least within the lower limit of normal
Hepatic: Bilirubin no greater than 2 times upper limit of normal (ULN) AST (angiotensin
sensitivity test) no greater than 2 times ULN Alkaline phosphatase no greater than 2
times ULN Renal: Creatinine no greater than 2 times ULN Other: No organic brain syndrome,
Alzheimer's disease, or other altered mental status No second malignancy within 5 years
except: Adequately treated nonmelanomatous skin cancer Adequately treated carcinoma in
situ of the cervix Not pregnant or nursing Negative pregnancy test Effective contraception
required of fertile patients

PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: No prior
fluorouracil or other chemotherapy for cancer No concurrent chemotherapy Endocrine
therapy: Not specified Radiotherapy: No prior or concurrent radiotherapy for cancer
Surgery: Complete en bloc resection required (see Disease Characteristics)