7B2, A POSSIBLE MARKER FOR NONFUNCTIONING PANCREATIC-ISLET CELL TUMOR

Plasma 7B2 was measured in 13 patients with pancreatic islet cell tumors, 11 with pancreatic adenocarcinoma and 31 normal subjects as a control. The mean (+/- SD) concentrations of plasma 7B2 in the normal subjects and the patients with pancreatic islet cell tumors were 67 +/- 10 and 1041 +/- 1786 pmol/l, respectively, and the value in the patients with pancreatic islet cell tumors was significantly higher than that in the normal subjects (p < 0.01). Elevation of plasma 7B2 over the normal range, defined as less than the mean + 3SD value of those in the normal subjects, was found in 10 of 13 patients with pancreatic islet cell tumors including 4 with nonfunctioning tumor. Plasma 7B2 dropped into the normal range postoperatively in 3 patients with nonfunctioning tumor, Plasma 7B2 concentrations in the patients with pancreatic adenocarcinoma remained in the normal range. These results raise a possibility that 7B2 is a useful marker for pancreatic islet cell tumors, in particular nonfunctioning tumor.