Clinical value of regional lymph node sorting in gastric cancer

BACKGROUND Increasing evidence have shown that regional lymph node metastasis is a critical prognostic factor in gastric cancer(GC).In addition,lymph node dissection is a key factor in determining the appropriate treatment for GC.However,the association between the number of positive lymph nodes and area of lymph node metastasis in GC remains unclear.AIM To investigate the clinical value of regional lymph node sorting after radical gastrectomy for GC.METHODS This study included 661 patients with GC who underwent radical gastrectomy at Tianjin Medical University General Hospital between January 2012 and June 2020.The patients were divided into regional sorting and non-sorting groups.Clinicopathological data were collected and retrospectively reviewed to determine the differences in the total number of lymph nodes and number of positive lymph nodes between the groups.Independent sample t-tests were used for intergroup comparisons.Continuous variables that did not conform to a normal distribution were expressed as median(interquartile range),and the Mann-Whitney U test was used for inter-group comparisons.RESULTS There were no significant differences between the groups in terms of the surgical method,tumor site,immersion depth,and degree of differentiation.The total number of lymph nodes was significantly higher in the regional sorting group(n=324)than in the non-sorting group(n=337)(32.5 vs 21.2,P<0.001).There was no significant difference in the number of positive lymph nodes between the two groups.A total of 212 patients with GC had lymph node metastasis in the lymph node regional sorting group,including 89(41.98%)cases in the first dissection station and 123(58.02%)cases in the second dissection station.Binary and multivariate logistic regression results showed that the number of positive lymph nodes(P<0.001)was an independent risk factor for lymph node metastases at the second dissection station.CONCLUSION Regional sorting of lymph nodes after radical gastrectomy may increase the number of detected lymph nodes,thereby improving the reliability and accuracy of lymph node staging in clinical practice.