Prognostic Value Of Metastatic Lymph Nodes Ratio In Advanced Gastric Cancer Patients

Background and Objective:Nowadays, the most commonly used staging system for gastric cancer is the TNM system established collaboratively by American Joint Committee on Cancer (AJCC) and the International Union for Cancer Control (UICC). This TNM system stratifies patients on the basis of depth of primary invasion (T), number of metastatic positive lymph nodes (N), and presence of distant metastasis (M). The 7th edition AJCC TNM stage system requires a minimum of 15 lymph nodes to be examined to determine the N stage. One hand, inadequate lymph node assessment would cause the tumor cell residual and a high recurrence rate. On the other hand, excessive lymph node assessment would cause the phenomenon of stage migration and inaccurate in survival prediction. It is still controversial weather N category system is the best system to evaluate the prognosis of gastric cancer patients extremely precise. Some researchers suggest the classification of metastatic lymph nodes should base on metastatic lymph nodes ratio, namely the number of metastatic lymph nodes to that of dissected lymph nodes. However, the suitable classification of metastatic lymph nodes to evaluate the prognosis of gastric cancer patients precise is still controversial in advanced gastric cancer patients. In this study, we want to evaluate the prognostic value of metastatic lymph nodes ratio in advanced gastric cancer patients.Methods:A total of 1930 advanced gastric cancer patients who underwent R0 surgery in Department of general surgery of Qilu Hospital of Shandong University were entered into a retrospectively maintained database between September 2011 and September 2014. All the patients underwent distal subtotal gastrectomy, proximal subtotal gastrectomy or total gastrectomy with D2 lymph node dissection. Metastatic lymph nodes ratio categories were identified as follows:MLR0:0%; MLR1:0 to 20%; MLR2: 20% to 50%; and MLR3:>50%. Compare the difference of prognostic value of N category system and metastatic lymph nodes ratio category system in advanced gastric cancer patients by SPSS.Results:1. The number of dissected lymph nodes and positive lymph nodes of advanced gastric cancer patients who underwent surgery in Department of gastrointestinal surgery is higher than that of other departments of general surgery, and the Median Survival Time is higher (P=0.045), while the ratio of patients with less than 15 examined lymph nodes is lower.2. Median Survival Time of advanced gastric cancer patients is correlated with age (P=0.001), tumor site (P=0.000), tumor size (p=0.000), T categories (p=0.000), N categories(p=0.000) and metastatic lymph nodes ratio (p=0.000). By multivariate analysis, metastatic lymph nodes ratio is an independent prognostic factor in advanced gastric cancer patients. The higher of the metastatic lymph nodes ratio, the worse of prognosis of advanced gastric cancer patients.3. Patients with...