A Nomogram for Predicting Overall Survival of Gastric Cancer Patients with Insufficient Lymph Nodes Examined.

Insufficient number of examined lymph nodes (eLNs) was considered to increase significantly the risk of stage migration in gastric cancer patients. The aim of our study is to establish a nomogram predicting the overall survival (OS) for patients with an insufficient number of eLNs. A total of 872 gastric cancer patients with extended lymphadenectomies were assigned randomly (2:1) to the development cohort and the validation cohort. The nomogram was established based on the Cox regression model using the development cohort. The concordance index (C-index) was used to evaluate the discriminative ability. We also compared our model with two other staging systems. Using multivariate analysis, age, sex, tumor location, depth of invasion, macroscopic type, lymphovascular invasion, the number of eLNs, and metastatic lymph nodes were selected and incorporated into the nomogram. The C-index of the nomogram was 0.742 and 0.743 in development and validation cohorts, respectively, which were significantly superior to the C-indices (range 0.705-0.712, all P < 0.001) of American Joint Committee on Cancer (AJCC) seventh edition and lymph node ratio staging systems in both cohorts. We established a nomogram which could predict accurately OS for gastric cancer patients with insufficient number of eLNs.