Liver macrophages contribute to pancreatic cancer-related cachexia.

Cachexia is a devastating process especially in pancreatic cancer patients and contributes to their poor survival. We attempted to clarify the pathological and molecular changes that occur in the liver during the development of cachexia. Using immunohistochemistry we investigated the infiltration of inflammatory mononuclear cells in liver biopsies of pancreatic cancer patients with or without cachexia, and the potential relevance of the cells for the nutritional and inflammatory status. Additionally, these findings were compared with the patients' clinical parameters. We found a significantly higher amount of CD68 immunoreactive macrophages in liver cross sections of patients with pancreatic cancer and cachexia. The number of CD68-positive macrophages was significantly inversely correlated with the nutritional status. Additionally, in these CD68-positive areas a significant increase in IL-6 and IL-1 immunoreactive cells was localized. Moreover, we found significantly increased areas of CD68-positive macrophages in liver biopsies of patients with a more dedifferentiated (aggressive) grading of the tumor. In conclusion, these results suggest that a crucial interaction between the tumor, PBMCs, and the liver may play a central role in the development and regulation of cachexia. Furthermore, pancreatic cancer may be able to alter systemic organ function even without obvious metastatic disease.