Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically confirmed primary colorectal adenocarcinoma

- Hepatic metastases that are considered completely resectable

- No more than 4 metastases by dual phase CT scan OR

- Hepatic metastases that are not completely resectable but are amenable to complete
destruction with resection and radiofrequency ablation

- More than 4 metastases allowed if all disease can be resected or destroyed in
situ with radiofrequency ablation

- No extrahepatic disease in any location

- No recurrent or second primary colorectal cancer by colonoscopy within the past year

- Received prior adjuvant chemotherapy with a fluorouracil-based regimen with the last
dose at least 1 month prior to surgery

- No prior radiofrequency ablation with residual viable intrahepatic disease by CT scan

- No plans to be treated with radiofrequency ablation alone without surgical resection

PATIENT CHARACTERISTICS:

Age:

- 18 and over

Performance status:

- ECOG 0-1

Life expectancy:

- Not specified

Hematopoietic:

- Absolute neutrophil count at least 1,500/mm^3

- Platelet count at least 100,000/mm^3

Hepatic:

- Bilirubin no greater than 1.5 times upper limit of normal (ULN)

- AST and ALT no greater than 5 times ULN

- No Gilbert's disease or other known defect in hepatic conjugation or glucuronidation

Renal:

- Creatinine no greater than 1.5 times ULN

Cardiovascular:

- No myocardial infarction within the past 6 months

- No congestive heart failure requiring therapy

Other:

- Not pregnant or nursing

- Fertile patients must use effective contraception during and for 30 days after study

- No other malignancy within the past 5 years except inactive non-melanoma skin cancer
or carcinoma in situ of the cervix

- No active serious infection

- No other serious underlying medical condition or severe concurrent disease that would
preclude study participation

- No dementia, significantly altered mental status, or psychiatric illness that would
preclude study participation

- No known hypersensitivity to irinotecan

- No known infection with HIV or AIDS

- No uncontrolled diabetes mellitus

- No history of seizures

- No drug or alcohol abuse within the past year

PRIOR CONCURRENT THERAPY:

Biologic therapy:

- Not specified

Chemotherapy:

- See Disease Characteristics

- No prior irinotecan

Endocrine therapy:

- Not specified

Radiotherapy:

- No prior radiotherapy to more than 30% of bone marrow

- No prior radiotherapy to the liver

- At least 3 months since prior radiotherapy to the pelvis or other areas

Surgery:

- See Disease Characteristics

- No prior resection of hepatic metastases (wedge biopsy allowed)

Other:

- No concurrent phenytoin, phenobarbital, or other antiepileptic medication

- No concurrent enrollment in other investigational drug trials