Unfavorable Outcomes of T3N0 Remnant Gastric Cancer After Distal Gastrectomy

Background/Aim: Remnant gastric cancer (RGC) after distal gastrectomy (DG) is a rare entity, and its prognostic determinants have not been fully clarified. Although current staging systems and treatment strategies for gastric cancer are well established, they are largely based on the primary disease, and their applicability to RGC remains uncertain. This study aimed to evaluate the clinicopathological characteristics and survival outcomes of patients with RGC after DG, focusing on tumor depth and lymph node status. Patients and Methods: This multicenter retrospective study evaluated patients who underwent curative resection for RGC arising in the upper stomach after DG at 10 institutions in Japan between January 2000 and December 2016. Clinicopathological factors, such as tumor depth and lymph node status, recurrence patterns, and overall survival (OS) were analyzed. Results: A total of 119 patients were included in the analysis. The 5-year OS rates for pathological stages I, II, and III were 77.5%, 52.9%, and 26.7%, respectively. On multivariate analysis, tumor invasion depth of T3 or deeper was an independent predictor of poor OS, while lymph node metastasis was not. Regarding T3 disease, patients with T3N0 tumors tended to have poorer survival than those with nodal metastasis. Hematogenous recurrence was more frequent in the T3N0 group, and none of the patients in that group received adjuvant chemotherapy. Conclusion: Tumor invasion depth was the most significant prognostic factor for RGC after DG. Patients with T3N0 RGC may represent a distinct subgroup with unfavorable outcomes, warranting further investigation into postoperative treatment strategies.