Prognostic Value of the Extramural Perivenous Infiltration in Locally Advanced Gastric Cancer: A Retrospective...

Gastric cancer (GC) remains a leading cause of cancer-related mortality worldwide. This study aims to investigate the prognostic value of extramural perivenous infiltration (EMPVI) and to establish a dynamic prediction model for locally advanced GC.

We retrospectively analyzed 223 consecutive patients with locally advanced GC who underwent D2 gastrectomy followed by adjuvant chemotherapy between September 2014 and April 2019. D2-40 and elastic fiber staining were performed to distinguish EMPVI and extramural venous invasion (EMVI), with results compared to hematoxylin and eosin (H&E) staining using weighted kappa (κ) statistics. The Kaplan-Meier method with log-rank test was used to estimate the 5-year disease-free survival (DFS). The chi-square (χ²) test was applied to analyze the associations between clinicopathological characteristics and EMPVI or 5-year DFS. Variables significant in univariate analysis were entered into a multivariate Cox regression model. All tests were two-sided, and P < 0.05 was considered statistically significant.

EMPVI was more common than EMVI (54.7% vs. 18.4%). EMPVI positivity correlated with worse 5-year DFS (P = 0.000) and was significantly associated with tumor stage (T), lymph node metastasis, perineural invasion, and tumor deposits (P < 0.01). Univariate analysis identified EMPVI, tumor stage (T), lymph node metastasis, perineural invasion, tumor deposits, Lauren classification, and tumor differentiation as risk factors for 5-year DFS (P < 0.05). Multivariate Cox regression analysis confirmed EMPVI (P = 0.000), Lauren classification (P = 0.001), and tumor stage (T) (P = 0.018) as independent prognostic indicators for 5-year DFS.

EMPVI serves as a novel and robust independent prognostic indicator in locally advanced GC.