ABSTRACT
Objective:To study the value of metastatic lymph node radio (rN) and pathological lymph node stage (pN) in evaluating the prognosis of patients after radical gastric cancer.Methods:The clinicopathological data of 491 patients who underwent radical gastrectomy in Tantai Yantaishan Hospital from Jan. 2013 to Dec. 2017 were retrospectively analyzed. X-tile software was used to group the metastatic lymph node radio by rN. According to the number of lymph node metastasis, pN stage was performed. The correlation between metastatic lymph node radio and other clinicopathological factors was assessed. The metastatic lymph node radio and the pathological lymph node stage in evaluating the prognosis of patients after radical gastric cancer were compared.Results:(1) X-tile analysis showed that the best cut-off values for the metastatic lymph node radio in this study were 0.14 (14%) and 0.63 (63%) . (2) According to the cut-off value, the 491 patients included in the study were divided into rN1 (256 cases) , rN2 (160 cases) , and rN3 (75 cases) three subgroups. The results of the analysis of differences showed that there were significant differencesbetween the groups in terms of tumor diameter, tumor location, surgical resection range, stage, lauren classification, degree of differentiation, pT, pN, vascular cancer emboulus, nerve invasion, and pathological TNM staging groups. (3) Comparison of rN and pN staging in evaluation of the prognosis of patients after radical gastric cancer: ①Kaplan-Meier survival analysis results showed that rN was better than pN. ② Both single factor and multivariate cox analysis showed that rN was an independent risk factor for the prognosis of gastric cancer. In univariate analysis, rN group HR=3.18 (95% CI 2.63-3.84, P<0.001) , pN stage HR=1.88 (95% CI 1.66-2.15, P<0.001) ; rN group HR=2.21 in multivariate analysis (95% CI 1.73-2.82, P<0.001) , pN staging HR=1.31 (95% CI 0.95-1.79, P=0.095) . ③The time-dependent ROC analysis showed that the prognostic ability of rN was better than pN staging before 52 months of postoperative follow-up, and pN staging was more advantageous after 52 months. ④The Lauren classification was used as a stratification factor for stratified analysis. The Kaplan-Meier survival curve indicated that rN was better than pN staging in intestinal, mixed and diffuse gastric cancer, and the AUC curve showed the prediction of rN in patients with mixed and diffuse gastric cancer was better than pN staging, while pN staging performance was slightly better in patients with intestinal gastric cancer. Conclusions:rN is an independent factor affecting the prognosis of patients after radical gastric cancer surgery. When judging the prognosis of patients within 52 months after radical gastric cancer, rN has a better prognostic value than pN. In patients with mixed and diffuse gastric cancer in the Lauren classification, rN shows better prognostic value.
ABSTRACT
PURPOSE: The important prognostic factors for gastric cancer are the depth of invasion by the primary tumor and the lymph node metastasis. The 5th edition of the Union Internationale Contrala Cancrums (UICC) TNM classification, which is based on the number of metastatic lymph nodes, has proved to be a reliable and objective method for predicting the prognosis of patients suffering with gastric cancer. However, its value for the prognosis of treating patients with serosal invasive (T3) gastric cancer, it is still being debated. So, we retrospectively studied the prognostic factors for T3 gastric cancer patients and we also evaluated the staging method according to the number of metastatic lymph nodes and the metastatic lymph node ratio. METHODS: This retrospective study was based on the medical records of 369 patients who underwent curative resection for serosal invasive (pT3) gastric cancer from 1992 to 2000. The patients were divided into four groups according to the number of metastatic lymph nodes and the clinicopathologic factors were evaluated by comparative study and the patients were then, classified into 4 groups by the metastatic lymph node ratio (0.5). We evaluated the prognostic factors and performed a survival analysis by using the Kaplan-Meier method and the Cox proportional hazard model. RESULTS: Among the four groups, the significant different factors were tumor size, the Borrmann type, the type of gastrectomy, the histologic type, and lymph node dissection. According to the univariate survival analysis, the tumor size, Borrmann type, lymph node stage, and the metastatic lymph node ratio significantly affected the prognosis. Yet, when comparing each survival rate, there was not significant difference between the pT3pN0 and pT3pN1 calassification. When we classified the metastatic lymph node ratio into 4 categories, each group then showed a significantly different survival rate. By conducting a multivariate analysis, only the metastatic lymph node ratio was an independent prognostic factor for serosal invasive gastric cancer (P=0.028). CONCLUSION: For evaluating patients with serosal invasive gastric cancer, there have been some problems with using the lymph node staging, so the metastatic lymph node ratio is a more reliable prognostic factor as it provides information about the extent of lymph node dissection and the degree of lymph node metastasis.