IS THERE A PROGNOSTIC DIFFERENCE BETWEEN FUNCTIONAL AND NONFUNCTIONALISLET-CELL TUMORS

BACKGROUND: Pancreatic islet cell tumors are categorized as either fun ctioning or nonfunctioning. Functioning islet cell tumors (FIT) elabor ate a variety of hormones, producing dramatic symptoms, while the init ial presentation of nonfunctioning islet cell tumors (NIT) is commonly an abdominal mass or symptom complex related to invasion of adjacent structures. As a result, NIT are purported to present at a later stage , with lower resectability rates, and an overall poorer prognosis, whe n compared to FIT. In addition, a number of reports have indicated tha t the incidence of NIT has increased significantly in recent years. PA TIENTS AND METHODS: Twenty-eight patients were studied retrospectively . All had islet cell tumors of the pancreas and were seen at the Unive rsity of Nebraska Medical Center and affiliated Nebraska Methodist Hos pital during a 19-year period. RESULTS: There were 9 patients (32%) in the NIT group and 19 (68%) in the FIT group. The mean ages at present ation were 61 years for the NIT and 52 years for the FIT group. In the NIT group, all presented with either abdominal pain (n = 7) or jaundi ce (n = 2). In contrast, over 90% of the patients with FIT had symptom s referable to the specific hormone elaborated by the tumor. Primary t umor size for MT was 4.1 +/- 0.7 cm versus 5.0 +/- 0.6 cm for the FIT group. No significant difference Tvas found for NIT versus FIT with re spect to the incidence of metastatic disease at presentation (44% vers us 53%), resectability rate with curative intent (44% versus 53%), or disease-free survival at 2 years (67% versus 40%). CONCLUSIONS: This s eries, in contrast to earlier reports, suggests that nonfunctioning is let cell tumors do not present at a more advanced stage, have lower re sectability rates, or an overall poorer long-term prognosis when compa red to functioning tumors.