Inclusion Criteria:

- Stage IV colorectal adenocarcinoma, excluding brain metastases

- Histological confirmation of colorectal adenocarcinoma

- Previously untreated patients

- Previously treated patients

- For the Phase I trial, no limitations

- For the Phase II trial, previous treated limited to adjuvant radiation and/or
chemotherapy which is completed at least 12 months before documentation of
metastatic disease; patients may not have received chemotherapy for metastatic
disease

- For the Phase I trial, patients may have measurable disease or unmeasurable disease;
for the Phase II trial, patients must have measurable disease in at least two
dimensions on x-rays, CT scan or MRI

- Expected survival of at least 16 weeks

- Performance status of >= 70% (Karnofsky)

- WBC >= 3000 uL

- Platelet count >= 100,000/uL

- Bilirubin =< 2 x ULN

- Creatinine =< 2 x ULN

- Not pregnant and not lactating; women of child bearing age must have negative
pregnancy test (beta-hcg)

- No allergies to interferon-gamma or E.coli derived products

- No serious medical intercurrent medical illnesses, including Class III or IV
cardiovascular disease; patient may not be dependent on immunosuppressive drugs
including corticosteroids, and may not receive these drugs for the entire duration of
the study

- No diarrhea, and with adequate oral intake

- Patients of child-bearing age and potential must agree to use adequate birth control
other than oral contraceptives for the entire duration of the study

- No previous or concurrent malignancy except inactive nonmelanoma skin cancer, in situ
carcinoma of the cervix, grade 1 bladder cancer, or other cancers if the patient has
been disease free for >= 5 years

- Patients must be oriented and rational, and aware of the investigational nature of
the study