Serum fatty acid synthase as a marker of pancreatic neoplasia.

Markers of early pancreatic cancer and its precursors are needed to improve the uniformly poor prognosis of this disease. Fatty acid synthase (FAS) catalyzes the synthesis of long-chain fatty acids and is overexpressed in most human solid tumors. We therefore evaluated serum FAS as a marker of pancreatic adenocarcinoma. FAS expression patterns in primary pancreatic adenocarcinomas, intraductal papillary mucinous neoplasms (IPMN), and chronic pancreatitis tissues were analyzed by immunohistochemistry. Serum FAS levels were determined by ELISA in 102 patients with pancreatic adenocarcinomas, in 42 patients with IPMNs, in 27 patients with chronic pancreatitis, and in 39 healthy control subjects. FAS protein was overexpressed in the ductal epithelium of 343 of 399 primary pancreatic adenocarcinomas (86.0%) and 28 of 30 IPMNs (93.3%), and in the islet and ductal cells in 3 of 54 chronic pancreatitis tissues (5.6%), whereas normal ductal epithelium lacked FAS expression. Serum FAS levels were significantly higher in patients with pancreatic ductal adenocarcinoma (first quartile median, 22.0; 4.5 ng/mL), in patients with IPMNs (20.7; 9.4 ng/mL), and in patients with chronic pancreatitis (31.1; 11.9 ng/mL) than in healthy controls (0; 0 ng/mL). FAS levels declined postoperatively in 8 of 9 patients with pancreatic adenocarcinoma and elevations of their preoperative serum FAS. In conclusion, serum FAS levels are elevated in patients with pancreatic cancer and IPMNs and are associated with neoplastic overexpression of FAS.