Expression of Trk tyrosine kinase receptor is a biologic marker for cell proliferation and perineural invasion of human pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a widely known severe malignancy with a poor prognosis. Perineural invasion extending to the extra-pancreatic nerve plexus, a significant concern in the treatment is frequently present in this cancer. We analyzed immunohistochemical expression of neurotrophins (NGF, BDNF, NT-3) and the cognate receptors, Trk tyrosine kinase receptor family (TrkA, B, C) and p75NGFR in 28 surgically resected PDAC specimens. A comparative study between several clinicopathologic factors and Trk receptors revealed a significant correlation between increased expression of TrkA and cancer proliferation, as well as TrkC and cancer invasion, including venous and perineural invasion. The present findings revealed a novel mechanism in PDAC progression that is mediated via a NTs-Trk interaction.