Correlation of IDO-1, LAG-3 and TIM-3 with clinicopathological features and prognosis of differentiated thyroid cancer / 中华核医学与分子影像杂志

ABSTRACT

Objective:To explore the expression of indoleamine 2, 3-dioxygenase 1(IDO-1), lymphocyte-activation gene 3 (LAG-3) and T cell immunoglobulin domain and mucin domain-containing molecule 3 (TIM-3) in differentiated thyroid cancer (DTC), and the value of them on prognosis.Methods:From May 2014 to November 2015, 119 DTC patients (33 males, 86 females, media age 42 years) who underwent surgical treatment in Shanghai Sixth People′s Hospital were retrospectively analyzed. The expressions of IDO-1, LAG-3 and TIM-3 in the specimens were analyzed by immunohistochemistry and the expression differences between cancer tissues and normal tissues were analyzed by χ2 test. The correlation of IDO-1, LAG-3 and TIM-3 with clinical characteristics were analyzed using logistic regression analysis. The patients were followed up for 5 years, and the relationships of the progression-free survival (PFS) rate with the expressions of the three immune checkpoints were analyzed by Kaplan-Meier method, log-rank test and Cox proportional hazard models. Results:The overall 5-year PFS rate for 119 DTC patients (median follow-up time 55(2-66) months) was 76.47%(91/119). The positive expression rates of LAG-3 and TIM-3 in cancer tissues were 21.85%(26/119) and 78.15%(93/119) respectively, which were significantly higher than those in normal thyroid tissues (7.34%(8/109) and 62.39%(68/109); χ2 values 9.43, 6.81, both P<0.05). While the positive expression rate of IDO-1 was 70.59%(84/119) in cancer tissues, which did not show a significant difference from that in normal thyroid tissues (64.22%(70/109); χ2=1.05, P>0.05). Factors associated with the positive expression of LAG-3 included tumors with a single lesion (odds ratio ( OR)=0.248, 95% CI 0.086-0.716, P=0.010). Log-rank test ( χ2=4.96, P=0.026) and multivariate Cox regression analysis (hazard ratio ( HR)=2.239, 95% CI 1.013-4.592, P=0.046) suggested that LAG-3 positive expression was an independent risk factor of PFS. The same analysis of TIM-3 found no clinicopathological factors related to TIM-3 positive expression ( OR 0.309-3.084, all P>0.05) and no association between TIM-3 positive expression and PFS ( χ2=0.008, P=0.929). Conclusion:The expressions of LAG-3 and TIM-3 are significantly increased in DTC tissues, and the higher expression of LAG-3 is associated with the worse prognosis, suggesting that LAG-3 may be a potential target for immunotherapy in DTC patients.