The Impact of Venous Invasion on the Postoperative Recurrence of pT1–3N0cM0 Gastric Cancer

The impact of venous invasion (VI) on postoperative recurrence in pathological (p)T1–3N0 clinical (c)M0 gastric cancer (GC) remains unclear. We investigated the association of VI grade with prognosis in 94 (78 stage I and 16 stage IIA) patients. VI was graded during pathological examinations based on the number of VIs per glass slide as follows: v0, 0; v1, 1–3; v2, 4–6; and v3, ≥7. Filling-type invasion in veins with a minor axis of ≥1 mm increased VI grade by 1. Four (4.3%) patients experienced recurrence. Recurrence increased with pT (pT1, 0.0%; pT2, 11.1%; pT3, 18.8%) and VI grade (v0, 0.0%; v1, 3.7%, v2, 14.3%; and v3, 40.0%). Recurrence was significantly more frequent in pT3 than pT1 and in v2 + v3 than v0 (p = 0.006 and 0.005, respectively). Kaplan–Meier curve analyses demonstrated a significant decrease in recurrence-free survival according to pT (p = 0.0021) and VI grade (p < 0.0001). Multivariate Cox analysis revealed a significant association of VI grade with recurrence (p = 0.049). These results suggest that VI grade is a potential recurrence predictor for pT1–3N0cM0 GC. No recurrence can be expected in cases with pT1 or VI grade v0. Adjuvant therapy might be considered for pT3 or VI grade v2 + v3.