Number and anatomical extent of lymph node metastases in gastric cancer: Analysis using intra-lymph node injection of activated carbon particles (CH40)

Background: The long-term survival of 200 patients with gastric cancer who underwent radical gastrectomy was analyzed with respect to the number and a natomical extent of lymph node metastasis. All of the patients received int ra-lymph node injection of fine activated carbon particle solution (CH40) d uring surgery. Methods: The average number of resected lymph nodes increased in fine with the anatomical level of lymph node dissection; 32.5 per patient in D1, 42.3 in D2,3 and 66.3 in D4. The percentage of blackened lymph nodes without me tastasis (42.4%) was slightly higher than that of lymph nodes containing me tastasis (37.2%), but the difference was not statistically significant. Of the 200 patients, 61 (30.5%) had microscopic evidence of metastatic lymph n ode involvement. Twenty-two patients had between one and three metastatic l ymph nodes, 19 had between four and nine and 20 patients had more than nine . The 5-year survival rate was 93.1% in patients without lymph node metasta sis, 71.9% in patients with 1-8 metastatic nodes, 36.1% in patients with 4- 9 nodes and 19.2% in patients with >9 nodes. Results: The 5-year survival rate according to the anatomical extent of met astatic lymph nodes was 93.1% in n0, 63.1% in n1, 37.9% in n2, 27.8% in n3 and 0% in n4. The number of metastatic lymph nodes and also their anatomica l extent were identified as independent prognostic factors for survival by multivariate analysis. Conclusion: The number and anatomical extent of metastatic lymph nodes have similar impacts on prognosis in gastric cancer.