First drainage lymph node(s) in gastric cancer: analysis of the topographical pattern of lymph node metastasis in patients with pN-1 stage tumors.

摘要

BACKGROUND: We attempted to identify the first lymph node(s) involved in metastasis of gastric cancer by studying the topographical pattern of metastasis to regional lymph nodes in patients with pN-1 stage tumors. MATERIALS AND METHODS: A total of 190 patients (108 males and 82 females; age range, 27 to 83 years; mean, 59.7 years), who had undergone curative resection combined with lymphadenectomy for solitary carcinoma of the stomach and were histologically diagnosed as having pN-1 stage tumors, were enrolled in the present study. The topographical patterns of metastasis to regional lymph nodes were reviewed from the pathology records of these patients. RESULTS: A total of 7561 lymph nodes (mean, 39.8/patient; range 15-99/patient) were dissected and metastasis was histologically observed in 523 nodes (6.9%, mean, 2.7/patient). Although perigastric lymph nodes were a common site of metastasis, the distribution of positive nodes depended on tumor location. As the number of positive nodes increased, a more diffuse pattern of regional involvement was noted. Skip metastasis was identified in 10 (5%) out of 190 patients. This unusual pattern of metastasis was found in 9 (14%) out of 63 patients with single positive nodes, while only one (1%) out of 127 patients with 2-6 positive nodes exhibited this pattern of metastasis. The difference between the two groups was statistically significant (p < 0.0001). CONCLUSION: Although perigastric lymph nodes are important first sites of drainage from pN-1 stage gastric tumors, the pattern of lymph node metastasis varies widely within a regional area even in pN-1 stage patients.