Prognostic Performance of Three Lymph Node Staging Systems in Patients After D2 Lymphadenectomy for Gastric Cancer

Abstract

Background Accurate staging of lymph node (LN) status is essential for predicting prognosis in patients with gastric cancer. Recent proposals suggest that lymph node ratio (LNR) and log odds of metastatic lymph nodes (LODDS) may have superior accuracy in predicting survival by minimizing stage migration. The aim of the present study was to compare the prognostic performances of the UICC (pN), LNR and LODDS staging systems and incorporate the optimal system into a nomogram for predicting individual survival in patients with resectable gastric cancer. Methods The study cohort comprised of 423 patients who had undergone D2 lymphadenectomy. The discriminatory powers of the different LN staging systems were compared using the concordance index (C-index). The optimal system was incorporated into a prognostic nomogram with other independent prognosticators, and bootstrap validation was performed. Results When LN status was assessed as a continuous variable, the LNR system (C-index: 0.712) was superior to pN (C-index: 0.695) and LODDS (C-index: 0.704). Age, LNR, and preoperative serum CA 19-9 and CA 125 were incorporated into a nomogram for predicting 2-year overall survival. Internal validation of the nomogram revealed good predictive abilities, with a bootstrap-corrected concordance index of 0.704. Conclusion Overall, LNR was the optimum predicator of survival in patients with resectable gastric cancer on the basis of LN status. LNR was incorporated into a nomogram along with age and preoperative serum CA 19-9 and CA 125. Internal validation confirmed the predictive ability of this nomogram.