The immunologic advantage of recurrent nasopharyngeal carcinoma from the viewpoint of Galectin-9/Tim-3-related changes in the tumour microenvironment.

Given salvage treatment for recurrent nasopharyngeal carcinoma (NPC) remains a clinical dilemma, immunotherapy targeting NPC-specific immunosuppression may bring new hope. We analyzed the expression of CD8, CD4, Foxp3 and Tim-3 in lymphocytes, and of Galectin-9 in tumour cells between paired primary and recurrent NPC from 95 patients and we noted that there was significant increase in the expression of Galectin-9+ tumour cells (p < 0.001) and Foxp3+ lymphocytes (p < 0.001) but a significant decrease in the expression of CD8+ lymphocytes (p = 0.01) between paired primary and recurrent NPC. Of all patients, 53 patients (55.79%) and 57 patients (60%) had increased percentages of Galectin-9+ tumour cells and of Foxp3+ lymphocytes, respectively. Conversely, 42 patients (44.21%) had decreased percentages of CD8+ lymphocytes. The patients with high Galectin-9 expression in recurrent NPC frequently also had high Tim-3 (p = 0.04) and Foxp3 (p = 0.01), and low CD8 (p = 0.04) expression in lymphocytes. After multivariate analyses, low CD8 expression in lymphocytes was an independent risk factor for relapse-free survival (p = 0.002) and overall survival (p = 0.02). Our data suggests that recurrent NPC may had more immunologic advantage than primary NPC, especially the Galectin-9/Tim-3 pathway. The immunotherapies targeting Galectin-9/Tim-3/Foxp3 interaction may serve as a potential salvage treatment for recurrent NPC.