47. Clinical significance of lymph node metastasis and micrometastasis for adenocarcinoma of the esophagogastric junction

Background and Objectives: The incidence of Adenocarcinoma of the Esophagogastric Junction (AEG) is increasing, but its surgical treatment is still debated for the unclear clinical significance of lymph node metastasis and micrometastasis (MM). The aim of this study is to clarify the pattern of lymph node metastasis and micrometastasis, and its potential significance for gastric cancer patients with AEG.
Methods: Study cohort was investigated retrospectively between 2000 and 2007, and clinical data was analysed according to lymph nodes metastasis. Lymph nodes were detected for micrometastasis by using an anticytokeratin-20 immunohistochemical stain in 36 AEG patients with pN0.
Results: There were 2884 lymph nodes under pathological examination in total. We identified lymph node metastasis in 188 of 364 patients (71.2%), and no lymph nodes metastasis in 76 patients (28.8%). The metastasis rates were relatively higher in No.1, No.2, No.3, No.7 and No.9 station of lymph nodes, while they were 47.88%, 25.76%, 38.26%, 46.51%, 40.98% respectively. Lymph node were detected with micrometastasis in 17 of 573 (2.97%) lymph nodes by CK-20 immunohistochemical stain. The lymph node stations and number of micrometastases were No.1 [7], No.2 (4), No.3 [5], and No.7 [1] respectively. Statistical results showed that lymph node metastasis and micrometastasis were significantly associated with tumor size (P<0.001) and T stage (P<0.001).
Conclusions: Our study demonstrate that lymph nodes of No.1, No.3 and No.7 station habor raletive higher rates of metastasis and micrometastasis in AEG. And this finding indicates that this flow might be one of the most important lymph node metastasis direction for AEG.