Treatment of Gastric Cancer: Early-Stage, Advanced-Stage Cancer, Adjuvant Treatment

With advances in understanding the spread of the primary tumor and patterns of recurrences of adenocarcinoma of the stomach and the availability of long-term follow-up data, a trend towards a tumor stage-stratified treatment strategy has increasingly received considerable attention. Because management and prognosis of early gastric cancer and advanced gastric cancer substantially differ and current advances in imaging technology allow us with increasing accuracy a pre-treatment staging of the disease, that is precondition for a differentiated treatment, we separately review the therapeutic approach of early and advanced gastric cancer. Emphasis is given on the risks and potential benefits of such a treatment strategy. EARLY GASTRIC CANCER here has been an increase in the rates of detection of gastric cancer at earlier tumor stages in the recent decades world-wide. However, this increase is much larger in Japan than in the USA and Europe. As a result of a well established nation-wide screening program in Japan, the proportion of EGC has been increased from 15%, a few decades ago, to 50% currently of all endoscopically diagnosed gastric cancers, whereas in the West where the low incidence of gastric cancer cannot justify a costeffective screening program, EGC accounts for approximately 15% only. Traditional surgery with partial or total gastrectomy with limited (D1) or extended (D2) lymph node dissection is associated with high overall survival rates of about 90% even in the West and a low, 2-3% rate of relapse at 10-years. Although, there was controversy in the past as to whether limited or extended lymph-node dissection should be performed for EGC, there is now an agreement that D1 node dissection is suitable for most cases. Conventional surgery has resulted in excellent long-term results that probably cannot be improved upon further. Thus the clinical and research interest in the last decade has been focused more on trying to improve QOL. Recently, there has been a trend toward minimally invasive treatment with endoscopic mucosal resection (EMR), laparoscopic surgery, and function preserving gastrectomy to minimise morbidity and to improve QOL. However, the well-accepted principles of surgical oncology should always be respected and long-term follow-up data are needed to establish that survival rates after these less radical operations are similar to those achieved by conventional surgery. The rationale for a minimally invasive treatment is the low incidence of lymph node metastasis for mucosal cancer (T1m). Recent reports of the histopathologic features of more than 13.000 patients, mainly Japanese, with EGC establish that only 2 % (range 0-4.8%) of patients with mucosal cancer have positive lymph nodes. 5-18 However, when the tumor invades the submucosal layer (T1sm) this rate is increased to about 20 % (range 1525%). Interestingly, the metastasis is not confined to the perigastric nodes (N1 level) only, but in about 5% (range 2.8 -6.4%) of patients with submucosal cancers the extraperigastric lymph nodes (N2 level) are also positive. Risk factors for N2 disease are patients with a submucosal lesion which is larger than 2cm. This finding is of clinical importance: there is a clear consensus that R0 resection is the most important independent treatment-related prognostic factor and a complete removal of metastatic N2 nodes would only be achieved by the more radical D2 lymph-node dissection. The histological data on the likelihood of lymph node Gastric Breast Cancer 2002; 1(1): 11-20