Lymph node metastases rate of locoregional and non-locoregional lymph node stations in gastric cancer

Background: The incidence of lymph node metastases is closely related to the T-stage, and therefore Eastern guidelines advice a D1 lymphadenectomy for early gastric cancer and a D2 lymphadenectomy for advanced gastric cancer. The aim of this study was to compare the lymph node metastases rate in the stations dissected with a D2-lymphadenectomy (stations 8-12) yet spared with a D1-lymphadenectomy, between different T-stages in a Western patient cohort. Methods: For this retrospective study, patients who underwent a gastrectomy in the Amsterdam University Medical Center (UMC), location Academic Medical Center (AMC), between 2011 and 2016 were identified from a prospectively maintained database. The primary outcome was to compare the rate of lymph node metastases in station 8-12 between different cT-stages. Results: One hundred twelve patients met our inclusion criteria. There were no positive lymph nodes in the lymph nodes stations 8-12 in cT1 and (y)pT1-stage tumors. The more advanced cT2-4 and (y)pT2-4 stage tumors show a high metastases rate (11.1% to 40.0%) in the lymph node stations 8-12. Conclusions: The results from this study endorse the Japanese Gastric Cancer Guideline; in early gastric cancer, a D1 lymphadenectomy is sufficient, while in advanced gastric cancer a D2 lymphadenectomy should be performed.