Venous Invasion Is a Risk Factor for Recurrence of pT1 Gastric Cancer with Lymph Node Metastasis

Background Postoperative adjuvant therapy for early gastric cancer (EGC) has not been widely studied, and there are differing indications for postoperative adjuvant therapy between Western and Asian countries. Japanese gastric cancer treatment guidelines do not recommend adjuvant chemotherapy for EGC, but it is unclear whether surgery alone is the most appropriate treatment. Methods This is a single-center retrospective study of 1001 consecutive patients who underwent radical gastrectomy for pT1 gastric cancer between 1999 and 2013 at the Wakayama Medical University Hospital. Results Recurrence was observed in 12 patients, nine of whom as the result of hematogenous metastasis. In all patients with pT1 gastric cancer ( n = 1001), lymph node metastasis was identified as an independent predictive factor for recurrence (hazard ratio [HR] = 10.910, P = 0.002). In patients with pT1N + gastric cancer, however, the 5-year disease-specific survival (DSS) rate was still high, 90.8%. In patients with pT1N + gastric cancer ( n = 97), the presence of venous invasion (pT1N + v +) was identified by univariate and multivariate analyses as an independent risk factor for recurrence (HR = 4.791, P = 0.032). In patients with venous invasion, the 5-year DSS rate was significantly lower than that in those without venous invasion (79.3% vs. 95.2%, P = 0.018). Conclusions Long-term prognosis of patients with EGC with lymph node metastasis is good, but venous invasion is associated with a higher risk of recurrence. Selective application of postoperative adjuvant chemotherapy for pT1N + v + gastric cancer may efficiently improve prognosis among patients with EGC.