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

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.