Inclusion Criteria

DISEASE CHARACTERISTICS:

- Diagnosis of neuroendocrine tumor of the duodenum/pancreas by histology or bone scan

- Functional or nonfunctional tumor

- Tumor meets ≥ 1 of the following criteria:

- Hepatic or extrahepatic metastases

- Progressive locally advanced tumor (primary or adenopathies)

- Unresectable disease

- Tumor differentiated and meets the following criteria:

- Ki 67 ≤ 15%

- Less than 10 mitoses per 10 large fields

- Measurable or evaluable disease

- Target lesions must meet 1 of the following criteria within the past 6 months:

- Increase of 20% in the longest diameter

- New metastases detected

- Minimum size of lesions must be 1 of the following:

- More than 15 mm for metastases

- More than 50 mm for primary tumor or local lymph nodes

PATIENT CHARACTERISTICS:

- WHO performance status 0-2

- Creatinine ≤ 1.5 mg/dL

- Absolute neutrophil count ≥ 1,500/mm^3

- Platelet count ≥ 100,000/mm^3

- Bilirubin ≤ 1.8 mg/dL

- No coronary insufficiency or symptomatic cardiac disease

- No intestinal obstruction, enteropathy, or uncontrolled chronic diarrhea

- No Gilbert's disease

- No psychological, social, familial, or geographic condition that would preclude study
treatment

- Not pregnant or nursing

- Fertile patients must use effective contraception during and for 6 months after
completion of study therapy

- No other condition that would preclude study therapy

PRIOR CONCURRENT THERAPY:

- No prior adjuvant radiotherapy

- At least 3 months since prior interferon

- Prior somatostatin analogs or antisecretories allowed

- No other prior treatment for this cancer

- No concurrent radiotherapy to the target lesion