2003 年 28 巻 2 号 p. 200-206
Background : In recent years, research has been conducted on the sentinel lymph node (SN) in relation to diverse forms of cancer. In addition, many multicentral clinical trials on breast cancer are currently in progress in many parts of the world. With respect to gastrointestinal malignancy, research has been started at numerous institutions, primarily in Japan. Yet it is still not clear whether the concept of the sentinel lymph node can be established. In the present study, therefore, a comparative investigation was made of the distribution of cases with actual metastatic lymph nodes among patients with gastric cancer in order to see if the concept can be established. Methods : Radioisotope (RI) was injected preoperatively into patients diagnosed with early gastric cancer and the sentinel lymph node was detected postoperatively. SN cases were defined as ones in which the lymph node RI magnitude was 0.02% ID or greater. A comparison was made between the distributions of SN and of metastatic lymph nodes (MN) in cases of early gastric cancer that had been excised. Results : The SN could be detected in 40 of 41 cases, and 35 of these cases could be diagnosed as pathological early cancer. However although no metastasis was found in the first lymph node group, metastasis was positive in the second lymph node group for both the MN group and SN group ; the positive cases appeared at approximately equal frequency for these groups. According to the N-category of the Japanese classification of gastric carcinoma and the lymphatic basin, tiwas found that the distributions of the MN group and SN group were roughly equal statistically. Conclusion : The distribution of cancer cells and RI in lymph nodes was roughly equal. Since the possibility that the true SN is present in lymph nodes detected by RI is high, it is indirectly related to the background of the SN concept in gastric cancer.