Retrieved lymph nodes from different anatomic groups in gastric cancer: a proposed optimal number, comparison with other nodal classification strategies and its impact on prognosis

Abstract

BackgroundThe optimal number of retrieved lymph nodes (LNs) in gastric cancer (GC) is still debatable and previous studies proposing new classification alternatives mostly focused on the number of retrieved LNs without proper consideration on the anatomic nodal groups’ location. Here, we assessed the impact of retrieved LNs from different nodal location groups on the survival of GC patients.MethodsStage I–III gastric cancer patients who had radical gastrectomy were investigated. LN grouping was determined according to the 13th edition of the JCGC. The optimal cut-off values of retrieved LNs in different LN groups (Group 1 and 2) were calculated, based on which a proposed nodal classification (rN) simultaneously accounting the optimal number and location of retrieved LNs was proposed. The performance of rN was then compared to that of LN ratio, log-odds of metastatic LNs (LODDs) and the 8th edition of the Union for International Cancer Control/American Joint Committee on Cancer (UICC/AJCC) N classification.ResultsThe optimal cut-off values for Group 1 and 2 were 13 and 9, respectively. The 5-year overall survival (OS) was higher for patients in retrieved Group 1 LNs > 13 (vs. Group 1 LNs ≤ 13, 63.2% vs. 57.9%, P = 0.005) and retrieved Group 2 LNs > 9 (vs. Group 2 LNs ≤ 9, 72.5% vs. 60.7%, P = 0.009). Patients staged as pN0–3b were sub classified using this Group 1 and 2 nodal analogy. The OS of pN0–N2 patients in retrieved Group 1 LNs > 13 or Group 2 LNs > 9 were superior to those in retrieved Group 1 LNs ≤ 13 and Group 2 LNs ≤ 9 (All P < 0.05); except for pN3 patients. The rN classification was formulated and demonstrated better 5-year OS prognostication performance as compared to the LNR, LODDs, and the 8th UICC/AJCC N staging system.ConclusionsThe retrieval of > 13 and > 9 LNs for Group 1 and Group 2, respectively, could represent an alternative lymph node retrieval approach in radical gastrectomy for more precise survival prognostication and minimizing staging migration, especially if > 16 LNs is found to be difficult.

A novel lymph node staging system for gastric cancer including modified Union for cancer Control/American Joint Committee on cancer and Japanese Gastric Cancer Association criteria

“…The fourteenth JGCA guidelines abandoned the anatomic node classification and adopted a numerical classification that includes four pN stages based on the number of mLNs much like that used in the UICC/AJCC classification [3,4]. The current Japanese guidelines were published in 2010, and since then most studies have focused on the numbers of metastatic and nonmetastatic LNs without additional consideration of the anatomical location [7,9,10]. However, basing the pN classification on the number of mLNs, regardless of their location, remains controversial.…”

Prediction Model of Lymph Node Metastasis Risk in Elderly Patients with Early Gastric Cancer before Endoscopic Resection: A Retrospective Analysis Based on International Multicenter Data

“…Since LN metastasis is recognized as an independent prognostic factor for GC, the occurrence of LN metastasis will greatly increase the risk of postoperative recurrence and shorten postoperative survival time in EGC 2 , 11 , 12 . It was reported that EGC patients with metastasis LNs (mLNs) had more than five times the risk of postoperative recurrence than EGC patients without metastasis 11 .…”

Development and validation of a novel staging system integrating the number and location of lymph nodes for gastric adenocarcinoma

“…12,13 The numeric LN staging system with multiple updates to the cut-off value showed high accuracy in survival prediction; however, some suggested limitations included lack of information on the anatomical extent of MLNs and the total number of LNs (TLNs) retrieved during surgery. [14][15][16][17] Son et al 14 proposed inclusion of the anatomic extent of MLNs in a staging system for more accurately predicting gastric cancer prognosis. Choi et al 18 developed an alternative LN staging system based on anatomical location, which reclassified the LN stations into lesser-curvature (LC), greater-curvature (GC), and extra-perigastric (EP) groups.…”