Metastatic Lymph Node Ratio in T3 Gastric Cancer Patients

Early studies had shown that metastatic lymph node (LN) was one of the most critical prognostic factors in gastric carcinoma (Hohenberger and Gretschel, 2003; Yokota et al, 2004; Dicken et al., 2005). Since the International Union Against Cancer tumor node metastasis (UICC TNM) classification for LN staging standard was modified in 1997, LN metastatic sites were replaced by the number of metastastatic LN to evaluate the prognosis of patients. However, the number of dissected LN affected the accuracy of N staging, or even leaded to N staging bias (de Manzoni et al., 2002). A lot of studies suggested that metastatic LN ratio (MLR), which is the percentage of metastatic LN among the total dissected LN, was considered as a better prognostic factor for patients with gastric cancer than number of metastatic lymph nodes because it overcomed the problem of N staging bias (Bando et al., 2002; Inoue et al., 2002; Nitti et al., 2003; Ding et al., 2004). A wider range of LN were removed in total gastrectomy that could better reveal the true rules of LN metastasis. Therefore, this study was carried out to evaluate its prognostic significance in T3 gastric cancer patients who underwent total gastrectomy and evaluated the difference of prognostic value between the MLR staging and the UICC TNM Classification (6th Edition) of gastric tumor.