Portal but not peripheral serum levels of interleukin 6 could interfere with glucose metabolism in patients with pancreatic cancer.

nterleukin 6 (IL-6), an autocrine growth factor for many tumors, seems to favour tumor spread to the liver. Our aims were first to evaluate the pattern of portal and systemic IL-6 levels in patients with pancreatic cancer (PC, n = 18) and chronic pancreatitis (CP, n = 22) compared with controls (CS, n = 20); and second, to ascertain whether there was any relation between IL-6 levels and tumor spread or PC-associated Diabetes mellitus. For all subjects, a fasting serum sample was obtained from a cubital vein; a portal serum sample was obtained from nine PC and three CP patients. In cubital and portal sera we measured IL-6, interleukin 1 beta (IL-1b), CA 19-9, c-reactive protein (CRP) and amylase. Systemic IL-6 levels were significantly higher in PC patients than in CS. In PC, portal IL-6 levels were significantly higher than the corresponding systemic values. The same pattern was found in the three CP patients, whereas IL-1b, CA 19-9, CRP and amylase portal levels were the same as systemic values. No correlation was found between PC stage and systemic or portal IL-6 levels. Portal IL-6 levels were correlated with the corresponding fasting serum glucose values. A significant correlation was found between IL-6 values and CRP, ALT, total bilirubin, GGT and creatinine, but not amylase. In conclusion: (1) Portal IL-6, which is partly of pancreatic origin, is first metabolised in the liver; (2) Systemic IL-6 reflects hepatic and renal functions rather than local conditions in the pancreas; (3) IL-6 does not appear to influence PC spread; (4) IL-6, which is released in large amounts by the inflamed pancreas, may contribute to determining diabetes, thus interfering with the signal transducing pathways involved in glucose metabolism in liver cells.