D2 dissection for gastric cancer

Abstract

Theodore Billroth successfully performed the first gastrectomy for cancer in Vienna in 1881. This was the beginning of modern gastric cancer surgery and provided the first real hope for cure from this form of cancer. Gastric cancer is a leading cause of cancer related mortality world wide, particularly in Central and South America, Japan and Korea, and in the Baltic Sea countries. In the United States, the incidence of gastric cancer has been on the decline since the 1930s. In 1996, it was estimated that there were 24,000 new cases of gastric cancer with 80–90% expected to die of their disease. The Japanese Research Society for Gastric Cancer has classified the draining lymph nodes of the stomach and assigned 16 different lymphatic stations. The nodes were then assigned to one of four echelons (N1–N4). Different locations of the cancer within the stomach require different forms of gastric resections. The Japanese have defined four levels of lymph node dissections (D1–D4), where specified lymph nodes from assigned lymphatic stations are dissected for a given type of resection. This was defined by the General Rules for the Gastric Cancer Study in Surgery and Pathology by the Japanese Research Society for Gastric Cancer in 1962 and revised in 1994. When a tumor has progressed to the muscularis propria or subserosa (T2), 8–31% of the second echelon lymph nodes (N2) will contain metastases. When a tumor has penetrated the serosa (T3), more than 40% of the second echelon lymph nodes will have metastases. Therefore, less than a D2 dissection will inadequately stage a significant population of patients. When retrospective series are reviewed at institutions committed to performing D2 dissections, the overall survival repeatedly shows improved results for patients undergoing D2 dissections when compared to D1 dissections. Moreover, there have been several large trials from all areas of the world which have shown similar morbidity and mortality results when D1 and D2 dissections have been compared. To date, there have been no trials which have been reproducible that have shown an improved survival in patients receiving adjuvant chemotherapy. Intergroup 0116 is currently studying the use of adjuvant radiation therapy in gastric cancer. We have not come far from the days of Theodore Billroth in the treatment modalities for gastric cancer. As surgical expertise and technology have improved, and the field of anesthesia has developed, survival of patients has improved. Only the extent of lymphatic dissection (D2 dissection) has proven beneficial to the outcomes of patients with this disease.