Characterization of Perineural Invasion As a Component of Colorectal Cancer Staging

Perineural invasion (PN) in colorectal cancer (CRC) is a site-specific prognostic marker, as mentioned by the AJCC Cancer Staging Manual, but it remains to be clearly defined. We aimed to identify an optimal characterization of PN as a component of cancer staging. On the basis of the anatomic features of the nervous system of the large bowel, site-specific pathologic criteria were assigned to PN according to the location of PN....