Robust vascular invasion concurrent with intense EGFR immunostaining can predict recurrence in patients with stage IB node-negative gastric cancer

The prognosis of most patients with stage IB node-negative gastric cancer is good without postoperative chemotherapy; however, about 10% suffer recurrence and inevitably die. We conducted this study to establish the optimal indications for postoperative adjuvant chemotherapy in patients at risk of recurrence. The subjects of this retrospective study were 124 patients with stage IB node-negative gastric cancer, who underwent gastrectomy at the Kitasato University East Hospital, between 2001 and 2010. We reviewed EGFR immunohistochemistry (IHC) as well as clinicopathological factors. Of the 124 patients, 47 (38%) showed intense EGFR IHC (2+ or 3+), with significantly less frequency than in stage II/III advanced gastric cancer (p < 0.001). According to univariate analysis, intense EGFR IHC was significantly associated with relapse-free survival (RFS) (p = 0.023) and associated with overall survival (OS) (p = 0.045) as well as vascular invasion (p = 0.031). On the multivariate Cox proportional hazards model, intense EGFR IHC(p = 0.016) was an independent prognostic predictor for RFS, and both vascular invasion (p = 0.033) and intense EGFR IHC (p = 0.031) were independent prognostic predictors for OS. The combination of both factors increased the risk of recurrence (p = 0.001). In stage IB node-negative gastric cancer, vascular invasion and intense EGFR IHC increase the likelihood of recurrence. We recommend adjuvant chemotherapy for such patients because of the high risk of metachronous recurrence.