157P - Lymph node ratio (LNR) a better prognostic factor after D2 gastrectomy

Background

Gastric cancer (GC) is among the most common malignancy worldwide. The UICC/AJCC TNM classification is the most commonly used classification system. For adequate N staging at least 15 lymph nodes should be retrieved. In some countries, this amount of lymph nodes is not met, which can lead to understaging. The phenomenon of stage migration is caused by an insufficient number of lymph nodes examined. In order to reduce stage migration, some investigators have proposed using the metastatic lymph node ratio (LNR), namely the ratio between positive lymph nodes compared with the total number of lymph nodes examined, as a new prognostic indicator for gastric cancer.

Methods

Total 116 patients who underwent upfront D2 gastrectomy between 2012 to 2017 were included. LNR has classified into 4 groups: LNR0; 0, LNR1; >0-0.13; LNR2; 0.14-0.40 and LNR3; 0.41-1. We have used Kaplan-Meier method to calculate survival rates and log rank test to compare survival curves between groups.

Results

Males (58.6%) were more common than females (41.4%). Mean age at presentation was 56.12 years. Most common mode of presentation was pain abdomen (53.8%). Most common location of tumor was distal part (81%). Most commonly done procedure was distal radical gastrectomy (56.9%) followed by subtotal gastrectomy (32.8%). Median number of lymph nodes isolated was 14. 54 patients received adjuvant chemotherapy while 32 patients adjuvant chemoradiation. At a median followup of 14 months (range, 2–78 months), overall 5-year survival was 23.75%. (Median survival: 24 months). The 5-year survival for Stages I–III was 100%, 26.25%, and 11.25%, respectively (P < 0.001). In the univariate analysis; sex (p < 0.05), tumor grade (p < 0.001), T stage (p < 0.001), N stage (p < 0.001), TNM stage (p < 0.001), and LNR (p < 0.001) were statistically significant. The multivariate analysis showed that tumor grade, T stage, N stage, TNM stage and LNR still had statistical significance. In subgroup analysis of patients with less than 15 obtained lymph nodes, LNR was still a significant predictor of survival.

Conclusions

LNR can estimate prognosis of patients who undergo D2 gastrectomy, regardless of the number of lymph nodes examined. Thus LNR may become a new indicator to evaluate prognosis after D2 gastrectomy.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.