Advances in research on the expression and role of molecules involved in perineural invasion in pancreatic cancer

One of the hallmarks of advanced pancreatic cancer is its ability of perineural invasion (PNI), which predicts its development and unfavorable prognosis. Recent years, many studies have indicated that a variety of molecular and intracellular signal pathways are correlated with PNI and associated pain. Some that have been further studied include activation of NGF-TrkA signaling, stimulation of chemokines CX3CR1, up-regulation ofmatrix metalloproteinase (MMP), degradation of extracellular matrix (ECM), and abnormality of immune system. PNI, secondary space occupation by tumor, damage of neurons by tumor cells, and angiogenesis all contribute to the pain that is difficult to alleviate by conventional anodyne. Nowadays, studies focus on targeting these signal pathways would improve treatment outcomes for patients with pancreatic cancer.