Published online Apr 15, 2020. doi: 10.4251/wjgo.v12.i4.457
Peer-review started: December 23, 2019
First decision: January 19, 2020
Revised: January 29, 2020
Accepted: February 17, 2020
Article in press: February 17, 2020
Published online: April 15, 2020
Processing time: 114 Days and 11.7 Hours
Hilar cholangiocarcinoma (HCCA) often produces perineural invasion (PNI) extending to extra-biliary sites, while significant confusion in the incidence of PNI in HCCA has occurred in the literature, however, the mechanism of this procedure remains unclear.
A better understanding of PNI may lend insight into tumor metastasis and recurrence and open doors to improved staging strategies, novel treatment modalities, and perhaps even paradigm shifts in our treatment of patients.
This study aimed to summarize the incidence of PNI in HCCA, and the authors try to provide the distribution of nerve plexuses around hepatic portal to clinical surgeons.
A clinicopathological study was conducted on sections from 75 patients with HCCA to summarize the incidence and modes of PNI. Immunohistochemical stains for CD34 and D2-40 in the cancer tissue were performed to clarify the association of PNI with microvessel and lymph duct. Sections of the hepatoduodenal ligament from autopsy cases were scanned and handled by computer to display the distribution of nerve plexuses around the hepatic portal.
The overall incidence of PNI in this study was 92%, while the rate of PNI in HCCA in the literature ranging from 38% to 100%. The incidence of PNI did not show any remarkable differences among various differentiated groups and Bismuth-Corlette classification groups. Logistic regression analysis identified the depth of tumor invasion was the only factor that correlated significantly with PNI. The authors did not find tumor cells invaded nerves via microvessels or lymph ducts.
The incidence of PNI of HCCA in Chinese population is around 92% and correlated significantly with a depth of tumor invasion. This should be considered when stratifying HCCA patients for further treatment.
Further investigations into the molecular basis of PNI could help develop therapeutic strategies targeted toward this aggressive tumor phenotype.