Evidence for the extent and oncological benefit of lymphadenectomy in gastric cancer

The oncological standard for curative treatment of non-metastasized gastric cancer is surgical resection with systematic D2 lymphadenectomy. Early stage carcinomas (pT1a) with circumscribed prerequisites are an exception as they can be endoscopically resected; however, by infiltration of invasive gastric cancer into submucosal layers (pT1b) the risk for lymph node metastases is up to 25-28%. Due to the lack of screening programs in the western world, most gastric cancers are diagnosed in an advanced stage and the treatment is multimodal with perioperative multiple chemotherapy and increasingly more also with immunotherapy. Nevertheless, despite multidisciplinary treatment strategies, the benefits of surgical resection and an adequate systematic lymphadenectomy are still independent prognostic factors for long-term survival; however, the classification and extent of the lymphadenectomy are regularly updated, especially as a result of the spread of minimally invasive operations, and in addition are internationally evaluated differently. In the context of perioperative morbidity and oncological outcome this includes the approach with respect to individual lymph node stations, especially lymph node stations 10 and 12a and in addition the classification D1-D3. Furthermore, continuous modifications, particularly from Asia, such as sentinel lymph node resection underline the pursuit of improvements. The multitude of alterations in the context of multidisciplinary treatment concepts and the international heterogeneity make the evaluation of the value of individual surgical aspects noticeably more difficult.