2. Patient has one or more metastatic tumors measurable by CT scan AND a serum CA19-9 measurement > 2 times the upper limit of normal. Patients must have measurable disease, defined as at least one lesion that can be accurately measured in at least one dimension (longest diameter to be recorded for non-nodal lesions and short axis for nodal lesions) as >20 mm with conventional techniques or as >10 mm with spiral CT scan.