Is tumor size a predictor of preoperative N staging in T2–T4a stage advanced gastric cancer?

BackgroundThe aim of this study was to assess the relationship between tumor size and preoperative N staging in patients with T2–T4a stage advanced gastric cancer.MethodsA total of 697 patients with gastric cancer were analyzed. The correlations between the number of metastatic lymph nodes (LNs) and other clinicopathologic factors were investigated. The Kappa consistency test was used to test the agreement between predicted and pathologic N staging.ResultsMultivariate analysis showed that tumor size was independently (r = 0.987, P < 0.05) and linearly (R2 = 0.940, P < 0.05) correlated with the number of metastatic LNs. The numbers of predicted metastatic LNs in patients with primary tumors <2.02 cm, 2.02–4.07 cm, 4.07–6.80 cm, and ≥6.80 cm in size were 0 (Stage N0), 1–2 (Stage N1), 3–6 (Stage N2), and ≥7 (Stage N3), respectively. There was good agreement between N staging predicted by tumor size and pathologic N staging (Kappa value = 0.531, P < 0.05). The overall accuracy of tumor size for preoperative N staging was 82.13%. The 5-year survival rates of patients with predicted Stages N0, N1, N2, and N3 were 80.0%, 71.1%, 56.8%, and 39.8%, respectively (P < 0.05). There were no significant differences in the survival rates of patients with predicted N staging and the corresponding pathologic N staging.ConclusionsTumor size is correlated with the number of LN metastases in patients with stage T2–T4a advanced gastric cancer. The measurements of tumor size can predict preoperative N staging.