Abstract: Objective · To detect T cell immunoglobulin mucin 3 (Tim-3) and galectin 9 (Gal-9) expression as well as CD3+ T cells and CD8+ T cells infiltration in the tumor tissues of adenocarcinoma of the esophagogastric junction (AEG), and analyze their correlations with the patients’ clinical characteristics and survival prognosis. Methods · A retrospective case study was used to collect clinical data and follow-up data of 116 AEG patients who were admitted to Renji Hospital, Shanghai Jiao Tong University School of Medicine from Dec. 2005 to Dec. 2013. Tim-3, Gal-9, CD3, and CD8 protein expressions were detected by immunohistochemistry in the tumor tissues, and the clinical characteristics and prognosis were compared among the patients with different levels of protein expression and T cells infiltration. Results · The results of immunohistochemistry showed that Tim-3 mainly expressed in the infiltrating immune cells, and Gal-9 mainly expressed in the tumor cells. The analysis on the clinical characteristics revealed that Tim-3 expression level was related to the Siewert classification (P=0.030) and CD8+ T cells infiltration level was related to the tumor TNM stage (P=0.042). The results of survival analysis showed that the patients with high level of CD8+ T cells infiltration had a better survival prognosis (P=0.047). However, there was no difference in the prognosis among the patients with different Tim-3 and/or Gal-9 expression levels or with different CD3+ T cell infiltration levels. Conclusion · AEG patients with high level of CD8+ T cells infiltration usually have earlier TNM stages and better prognosis. There is no significant difference in the prognosis of AEG patients with different Tim-3/Gal-9 expression levels.

Key words: adenocarcinoma of the esophagogastric junction (AEG), T cell immunoglobulin mucin 3 (Tim-3), galectin 9 (Gal-9), survival prognosis