Harvest of at Least 23 Lymph Nodes is Indispensable for Stage N3 Gastric Cancer Patients.

BACKGROUND: The National Comprehensive Cancer Network (NCCN) recommends that at least 15 lymph nodes (LNs) be removed during radical gastrectomy. This study aims to investigate the optimal number of LNs resected for radical gastrectomy. PATIENTS AND METHODS: From September 2008 to March 2015, a total of 1990 gastric cancer patients were enrolled in this study. Clinicopathological features and survivals were recorded, and the association between the number of LNs resected and the prognosis of gastric cancer were analyzed. RESULTS: Overall, 1520 males (76.4%) and 470 females (23.6%) were included in the study, with a median age of 57 years (range 20-90). The median number of LNs resected was 24 (range 15-83) for stage N1, 25 (range 15-62) for stage N2, 25 (range 15-88) for stage N3a, and 28 (range 16-73) for stage N3b. The optimal cut-off value for the number of LNs resected was 22 for stage N3a (p = 0.000) and N3b (p = 0.003) patients, while no other cut-off value was significantly superior to 15 for stage N1-2 patients (both p > 0.05). Age, tumor size, tumor depth, and number of LNs resected were independent prognostic predictors for stage N3a patients, while resection type and number of LNs resected were independent prognostic predictors for stage N3b patients. Removing more than 22 LNs exhibited a significant survival benefit compared with removing 15-22 LNs for stage N3a and N3b patients (29.7 vs. 21.6%, p = 0.000; 12.9% vs. 0%, p = 0.003, respectively). CONCLUSION: Removing at least 23 LNs could yield better survival outcomes in stage N3 gastric cancer patients.