Lymph Node Evaluation in Robot-Assisted Versus Video-Assisted Thoracoscopic Esophagectomy for Esophageal Squamous Cell Carcinoma: A Propensity-Matched Analysis
BACKGROUND AND OBJECTIVES Although the three-field lymphadenectomy has established as a standard operation for esophageal cancer in Japan, criticism remains due to the lack of randomized controlled trials with a high EBM level. This retrospective study aims to clarify the effectiveness of the three-field lymphadenectomy using the data obtained from 906 consecutive patients with esophageal cancer who underwent R0 esophagectomy with the three-field lymphadenectomy. METHOD Efficacy Index (EI) was calculated for each lymph node station and grossly cervical, mediastinal, or abdominal dissection field. The values of EI were compared according to main tumor location. RESULTS Cervical lymph node dissection had high EI in upper and middle thoracic esophageal cancer but it was very small in lower esophageal cancer. Abdominal lymphadenectomy for upper thoracic esophageal cancer had some but limited efficacy only in paracardiac and lesser curvature stations. Cervical lymphadenectomy for lower esophageal cancer showed some but limited efficacy only in cervical paraesophageal stations. CONCLUSION Our investigation clearly shows the effectiveness and importance of wide range lymph node dissection defined as D3 according to the Japanese N-grouping system for thoracic esophageal cancer. The three-field lymphadenectomy is regarded as a standard procedure for upper and middle thoracic esophageal cancer.