OBJECTIVETo establish a preoperative scoring system to predict the lymph node metastases (N) in gastric cancers.

METHODSThe clinicopathologic data of 291 cases with gastric cancer were analyzed retrospectively. The factors influencing significantly actual lymph node status (pN) were selected through the univariate and the multivariate analysis, and the score of each factor was identified. Scores predicting different N stages were identified using receiver operating characteristic curves. The N stages defined by the score system were compared with the actual pN status using kappa statistics and diagnostic test.

RESULTSTumor size, depth of invasion and histopathological types were selected to establish the scoring system. According to this score system, scores 0-4 predict N0, scores 5-7 predict N1, scores 8-9 predict N2 and scores 10-13 predict N3. There was a good agreement between N stages predicted by the scoring system and the actual pN status (weighted kappa = 0.605, u = 14.548, P < 0.0001). The crude agreement, positive predictive value and negative predictive value of the scoring system were 82.8%, 65.6% and 88.5%, respectively.

CONCLUSIONThe scoring system can provide accurate and reliable information to predict the lymph node metastases of gastric cancers preoperatively. It is simple and practical to use in clinical work and can help surgeons to choose an optimal extent of lymph node dissection for gastric cancer.