The Prognostic Effect of Metastatic Lymph Node Ratio in Operated Gastric Cancer Patients.

Objective: To assess the prognostic importance of metastatic lymph node ratio (MLNR) in operated gastric cancer patients.

Study Design: Observational study.

Place And Duration Of Study: Health Sciences University, Yildirim Beyazit Diskapi Training and Research Hospital, Department of General Surgery, Ankara, Turkey, between January 2014 and March 2019.

Methodology: Initially, record of a total of 171 patients, operated for gastric cancer, were retrieved. Inclusion criteria involved having gastric adenocarcinoma, undergoing curative-intent surgery, absence of neoadjuvant chemotherapy, dissection of ≥15 lymph nodes, negative surgical margins, and no mortality within the first 30 days after surgery. Thirty patients were excluded for various reasons. Thus, clinicopathological features and prognostic factors including MLNR on overall and disease-free survival (DFS) were evaluated for the remaining 141 patients.

Results: The median age of the 141 patients was 63 years (IQR: 54 - 72 years). The median MLNR was 0.18 (IQR: 0 - 0.47). The cut-off value with highest sensitivity and specificity was determined as 0.25 (area under the curve (AUC); 0.724, CI 95%; 0.639-0.808, p <0.001) in ROC curve analysis. Multivariable Cox regression analysis showed MLNR and perineural invasion (PNI) as independent prognostic factors. Patients with MLNR >0.25 had a 2.39-fold higher risk of disease progression, and 3.76-fold higher risk of shorter survival.

Conclusion: The study contributed to the literature that MLNR is practical and useful as an independent prognostic factor predicting survival even better than tumor/node/metastasis (TNM) staging system.  Key Words: Gastric cancer, Metastatic lymph node ratio, Prognostic factor, Surgery.