Endoscopic submucosal dissection in early gastric cancer with papillary histological type.

Abstract

412 Background: Gastric papillary adenocarcinoma has been regarded as differentiated-type adenocarcinomas along with well- or moderately-differentiated tubular adenocarcinomas in current endoscopic submucosal dissection (ESD) indication. We aimed to investigate lymph node metastasis (LNM) and to verify the safety of ESD in patients with papillary early gastric carcinoma (P-EGC). Methods: 4,264 patients with early gastric cancer (EGC) underwent curative gastrectomy between October 2000 and December 2017 at National Cancer Center, Korea. Among them, 45 patients were pathologically confirmed with P-EGC. We compared clinicopathological factors among differentiated-type EGC except P-EGC (n=2,106), undifferentiated-type EGC (n=2,113), and P-EGC. Logistic regression model was used to investigate risk factors of LNM. Results: P-EGCs were frequently located in lower third of the stomach (71.1%, P < 0.001), and about half of them (46.7%, P < 0.001) had elevated morphology. Mucosal cancer of P-EGC (37.9%) was significantly lower than differentiated-type (48.8%) and undifferentiated-type EGC (22.2%, P < 0.001). Angiolymphatic invasion and LNM occurred most frequently in P-EGC (46.9% and 20.0%, respectively) compared to differentiated-type (18.9% and 9.2%, respectively) and undifferentiated-type EGCs (10.9% and 11.7%, respectively; P < 0.001 and P = 0.004, respectively). P-EGC that was not mixed with other pathological type tended to have increased risk of LNM referent to differentiated EGC. (Odd ratio [OR] 2.53, 95% confidence interval [CI], 0.99-6.50). Among 45 patients with P-EGC, 13 patients met the current ESD indication; 3 patients corresponded to absolute indication and 10 patients did expanded indication. One patient had LNM and met expanded criteria with submucosal invasion less than 500 μm. In multivariate analysis, OR for LNM meeting expanded indication of P-EGC was 40.67 (95% CI, 2.54-702.76) referent to that of absolute indication compared to LNM meeting expanded indication of non-papillary EGC (10.28, 95% CI, 1.37-77.04). Conclusions: When ESD was applied to P-EGC, it should be carefully performed because of high rate of submucosal invasion and high risk of LNM even in with submucosal invasion less than 500 μm.