Characeristics of lymph node metastasis in early gastric cancer and feasibility of endoscopic resection

Objective To compare the clinicopathologic features of different types of early gastric cancer （ EGC）, and to investigate the risk factors of lymph node metastasis （LNM） and to explore the possi- bility of endospic resection（ER）. Methods The clinical data of the 524 EGC patients who underwent a curative gastrostomy between January 2000 and May 2011 in the hospital were analyzed, retrospectively. Clinieopathologic features were compared between different histological types and investigated by univariate and multivariate analysis for their possible relationship with LNM. Results Tumor size and depth of tumor invasion for signet ring cell cancers were significantly different from differentiated cancers and poorly differen- tiated cancers. The incidence of LNM for signet ring cell carcinoma was lower than poorly differentiated car- cinoma （9. 7% vs. 22. 2% ,P 〈 0. 05）, but not significantly different compared to differentiated cancers （ 13.1% ,42/321, P =0. 406）. Tumor size （P =0. 007）, depth of tumor invasion （P =0. 000）, histologi- cal ~ type （ P = 0. 030 ） , lymphatic involvement （ P = 0. 000 ） and ulceration （ P = 0. 002 ） showed positive correlations with LNM by univariate analysis. Multivariate analysis revealed that depth of tumor invasion （ P = 0. 007 ）, tumor size （ P = 0. 010 ）, histological type （ P = 0. 000 ）, and lymphatic involvement （ P = 0. 000） were independent risk factors of LNM. In signet ring cell carcinoma with mucosal invasion andwithout lympatic involvement, which were less than 2 cm in tumor diameter, no LNM was detected. Conclusion Early signet ring cell cacinoma has different clinicopathologic features from differentiated carci- noma and poorly differentiated carcinoma. We propose early signet ring intramucosal EGC 2 cm or less in size without lymphatic involvement can be performed by ER. Key words: Early gastric cancer;  Lymph node metastasis ;  Risk factors;  Endoscopic resection