%0 Journal Article
%T Perineural invasion score system and clinical outcomes in resected pancreatic cancer patients.
%A Nozzoli F
%A Catalano M
%A Messerini L
%A Cianchi F
%A Nassini R
%A De Logu F
%A Iannone LF
%A Ugolini F
%A Simi S
%A Massi D
%A Geppetti P
%A Roviello G
%J Pancreatology
%V 24
%N 4
%D 2024 Jun 15
%M 38514359
%F 3.977
%R 10.1016/j.pan.2024.03.004
%X <B>OBJECTIVE: </B>Perineural invasion (PNI), classified according to its presence or absence in tumor specimens, is recognized as a poor prognostic factor in pancreatic ductal adenocarcinoma (PDAC) patients. Herein, we identified five histological features of PNI and investigated their impact on survival outcomes of PDAC resected patients.<BR><B>METHODS: </B>Five histopathological features of PNI (diameter, number, site, sheath involvement, and mitotic figures within perineural invasion) were combined in an additional final score (ranging from 0 to 8), and clinical data of PDAC patients were retrospectively analyzed. PNI + patients were stratified in two categories according to the median score value (<6 and ≥ 6, respectively). Impact of PNI on disease-free survival (DFS) and overall survival (OS) were analyzed.<BR><B>RESULTS: </B>Forty-five patients were enrolled, of whom 34 with PNI (PNI+) and 11 without PNI (PNI-). The DFS was 11 months vs. not reached (NR) (p = 0.258), while the OS was 19 months vs. NR (p = 0.040) in PNI+ and PNI- patients, respectively. A ≥6 PNI was identified as an independent predictor of worse OS vs. <6 PNI + patients (29 vs. 11 months, p < 0.001) and <6 PNI+ and PNI- patients (43 vs. 11 months, p < 0.001). PNI ≥6 was an independent negative prognostic factor of DFS vs. <6 PNI+ and PNI- patients (13 vs. 6 months, p = 0.022).<BR><B>CONCLUSIONS: </B>We report a PNI scoring system that stratifies surgically-treated PDAC patients in a graded manner that correlates with patient prognosis better than the current dichotomous (presence/absence) definition. However, further and larger studies are needed to support this PNI scoring system.