Intraoperative Surrogate Indicators of Gastric Cancer Patients' Long-Term Prognosis: The Number of Lymph Nodes Examined Relates to the Lymph Node Noncompliance Rate.

Abstract

BACKGROUND: The number of examined lymph nodes (ExLNs) and the rate of lymph node (LN) noncompliance are two independent indicators for evaluating the oncological efficacy for radical gastric cancer (GC) surgery. There are no studies to prove the relationship between these two indicators and their influence on the long-term prognosis of GC patients. METHODS: The clinicopathological data of 1872 patients with radical GC resection with pathological stage pT2-4N0-3M0 from June 2007 to June 2013 were retrospectively analyzed. Noncompliance was defined as patients with more than one or more LN stations absence as described in the protocol for lymphadenectomy in the Japanese Gastric Cancer Association. RESULTS: Among 1872 patients, 941 (50.3%) had complete LN compliance, 469 (25.1%) had minor LN noncompliance, and 462 (24.6%) had major LN noncompliance. Logistic regression analysis showed that cT staging and ExLNs were independent risk factors for LN noncompliance. In the whole group, Kaplan-Meier survival curve elucidated that overall survival (OS) differences of ExLNs ≤ 25 and ExLNs > 25 were statistically significant (p < 0.001). Stratified analysis of LN noncompliance elucidated no statistically significant difference in OS of these two group. Multivariate COX regression analysis suggested that LN noncompliance was an independent prognostic factor for OS, whereas ExLNs was no longer an independent prognostic factor for OS. CONCLUSIONS: The increase number of ExLNs can improve the OS of GC patients, which depends on the decrease of LN noncompliance rate. As surrogate indicators for long-term prognosis of GC patients, LN noncompliance rate was better than ExLNs number.