ABSTRACT
@# Objective: To investigate the expressions of programmed death ligand 1（PD-L1）in triple-negative breast cancer (TNBC) and its correlation with angiogenesis. Methods: 120 cases of TNBC patients who underwent surgery in the Fourth Hospital of Hebei Medical University from March 1, 2011 to June 1, 2012 were collected. The tumor tissues of patients were surgically resected and confirmed by pathology. PD-L1 protein expression in TNBC tissues of 120 patients was detected by tissue microarray combined with immunohistochemistry, and its relationship with various clinical indicators was analyzed. Blood vessels and lymphatic vessels were labeled withCD34andD2-40todetectmicrovesseldensity(MVD)andlymphaticvesseldensity(LVD)inTNBC.Results:Thepositiveexpression rate of PD-L1 in the tumor cells and interstitial infiltrating lymphocytes fromTNBC was 56.7% (68/120); No correlation was found between PD-L1 protein expression and the gender, age, histological grade, clinical stage, or tumor size of patients with TNBC (P>0.05), but related to the lymph node metastasis (P<0.05) and vascular thrombus (P<0.05). TNBC with high PD-L1 expression exhibited high incidence of lymph node metastasis and formation of vascular thrombus, and the expression of PD-L1 was positively correlated with MVD (r=0.500, P=0.02) as well as LVD (r=0.662, P=0.01). Log-Rank test showed that the survival time of TNBC patients with positive PD-L1 protein expression was significantly shorter than that of patients with negative expression (P<0.05). Cox multivariate analysis suggested that PD-L1 protein expression could be an independent prognostic factor for TNBC overall survival. Conclusion: PD-L1 plays an important role in TNBC angiogenesis and lymphangiogenesis, and is closely related to TNBC invasion and metastasis; blocking PD1/PD-L1 signal pathway is expected to be an effective new strategy for TNBC treatment.