Risk factors of lymph node metastasis in 734 early gastric carcinoma radical resections in a Chinese population

OBJECTIVE To investigate the risk factors of lymph node metastasis (LNM) in early gastric carcinoma (EGC) in a Chinese population. METHODS The data were analyzed to determine risk factors of LNM. The patients' characteristics, the tumor's location, gross features, histological type, differentiation, invasive depth, lymphovascular invasion (LVI), perineural invasion and the numbers of lymph nodes retrieved and involved were statistically analyzed. RESULTS A total of 734 patients with EGC were finally enrolled in the study, and LNM was present in 14.2% (104/734) of them. By univariate analysis, significant risk factors for LNM included depressed or excavated gross patterns, size >= 1.0 cm, SM2, moderate/poor differentiation, histological type of hepatoid or micropapillary adenocarcinoma, LVI, perineural invasion and tumor necrosis. By multivariate analysis, independent risk factors for LNM were size >= 3.0 cm (odds ratio [OR] 4.9), SM2 (OR 2.4), moderate (OR 3.6) and poor (OR 5.0) differentiation, LVI (OR 3.1) and tumor necrosis (OR 1.7). Early gastric cardiac carcinoma (OR 0.3) had a significantly lower risk than non-cardiac carcinoma. No LNM was identified in 67 EGC of <1.0 cm in size and without poor differentiation, in 142 intramucosal EGC cases of smaller than 2.0 cm and without poor differentiation, in 129 cases of well-differentiated EGC without deep SM2 submucosal invasion, or in 54 intramucosal EGC located in the gastric cardia. CONCLUSION Independent risk factors for LNM in EGC include tumor size >= 3.0 cm, SM2 invasion, moderate/poor differentiation, LVI and tumor necrosis. Early cardiac carcinoma had a significantly lower risk of LNM than non-cardiac EGC.