Different risks of nodal metastasis by tumor location in remnant gastric cancer after curative gastrectomy for gastric cancer.

ABSTRACT

BACKGROUND: Curative surgery for remnant gastric cancer (RGC) after gastrectomy for gastric cancer (GC) can be challenging. We examined the risk factors for lymph node metastasis in RGC, especially for tumors located at the greater curvature (G) or non-greater curvature (NG), to determine the appropriate indications of curative surgery. METHODS: Data from the two high-volume centers of Japan between 1998 and 2018 were retrospectively reviewed. Among the 137 patients enrolled in this study, 34 were classified as the G group and 103 as the NG group. The incidence of lymph node metastasis and its risk factors was evaluated. RESULTS: Lymph node metastasis was observed in 21.2% (29/137), including 38.2% (13/34) in the G group and 15.5% (16/103) in the NG group (p = 0.008). A logistic regression analysis showed that tumor location of G or NG (p = 0.042), tumor size (p = 0.002) and depth of invasion (p = 0.009) were significant independent risk factors for nodal metastasis. Risk classification using these factors showed that clinical T1-T2 with a maximum size < 35 mm located at the non-greater curvature had the lowest nodal metastatic risk (4.3%). CONCLUSIONS: Tumor location at the G or NG was a significant risk factor for nodal metastasis in RGC. When selecting curative surgery for RGC, physicians should consider the nodal metastatic risk calculated by the tumor location, size and depth of invasion.