Expression and clinical significance of PD-1 /PD-L1 in gastric cancer tissues / 中国肿瘤生物治疗杂志

ABSTRACT

@#[Abstract] Objective: To investigate the expression and clinical significance of PD-1/PD-L1 in gastric cancer (GC) tissues. Methods: Paraffin embedded tumor tissues and clinical data of 82 GC patients who had undergone operation at the Fourth Hospital of Hebei Medical University from January 2007 to December 2007 were collected, and their survival status was followed. The protein expressions of PD-1 and PD-L1 in tumor tissues were detected by immunohistochemistry. Kaplan-Meier analysis and Log-Rank test were adopted to analyze the survival of GC patients, and the ROC curve was plotted. Results: The positive rate of PD-L1 protein expression was 42.68% while the positive rate of PD-1 expression was 13.41% in GC tissues. The positive rate of PD-1 and PD-L1 expression in GC tissues of patients without pre-operative distant metastasis was significantly lower than those patients with pre-operative metastasis (PD1： 3.28% vs 42.86%; PD-L1： 13.11% vs 90.48%; all P<0.01). The positive rate of PD-L1 expression in tumor stroma of patients without pre-operative distant metastasis was significantly lower than those with metastasis (PD-L1 13.11% v s 47.62%, P<0.01). The resection range of stomach, PD-L1 over-expression and the presence of pre-operative distant metastasis were the adverse factors affecting the prognosis of patients with GC (P<0.05). Conclusion: PD-1 and PD-L1 expressions in GC tissues were closely related to the presence of pre-operative distant metastasis and the depth of tumor infiltration. The postoperative survival of patients who were PD-L1 positive was shorter than the negative ones.