Clinical risk factors for splenic hilar nodal metastasis in remnant gastric cancer after distal gastrectomy.

Abstract

270 Background: Splenectomy is usually considered to be required for complete dissection of splenic hilar lymph node (#10 LN) in gastric cancer (GC). Although spleen-preserving D2 was established for the advanced GC not invading the grater coverture based on the JCOG0110 clinical trial, D2 gastrectomy with splenectomy remains the standard procedure for the advanced GC involving grater coverture in Japan. However, the applicability of this treatment for remnant gastric cancer (RGC) is unclear because the lymphatic flow and lymphatic metastatic pattern may have been changed after initial gastrectomy. There are no guidelines for splenic hilar nodal dissection for RGC. In this study we evaluated risk factors for #10 nodal metastasis in RGC. Methods: This study retrospectively examined RGC patients who received gastrectomy with #10 nodal dissection after distal gastrectomy at two high-volume cancer centers in Japan between 1998 and 2015. Results: 99 patients were entered in this study. The #10 nodal metastatic rate was 12.1% (12/99). Initial gastrectomy was performed for benign in 42 patients and for malignant in 52 patients. The median duration from the initial gastrectomy was 20 (1-55) years. Main tumor location was lesser curvature in 46 patients, anterior wall in 11, greater curvature in 19, posterior wall in 11, and the whole in 12. Large type 3(≥8cm) and type 4 were found in 18 cases. The median tumor size was 50 (10-232) mm. The depth of invasion was cT1 in 31 patients, cT2 in 19, cT3 in 11, cT4a in 28, and cT4b in 10. Histology was differentiated type in 46 patients and undifferentiated type in 56. Completion gastrectomy was performed in 98 patients and partial gastrectomy in 1. 89 patients underwent splenectomy. The univariate analysis showed that tumor location (lesser curvature vs others, p=0.027) and depth of invasion (cT1-3 vs cT4, p=0.032) were significant risk factors for #10 nodal metastasis. By multivariate analysis, these two factors remained significant. Metastasis to #10 nodal metastasis was 0% (0/28) in patients without both risk factors, 11-12% in those with at least one risk factor, and 30% (6/20) in those with both risk factors. Conclusions: The tumors not confined to the lesser curvature and cT4 were significant risk factors for #10 nodal metastasis of RGC after distal gastrectomy. Splenectomy should be considered for complete splenic hilar nodal dissection when these risk factors are positive.