RT Journal Article SR Electronic T1 Clinicopathological and Prognostic Significance of Programmed Death Ligand-1 SP142 Expression in 132 Patients With Triple-negative Breast Cancer JF In Vivo JO In Vivo FD International Institute of Anticancer Research SP 2890 OP 2898 DO 10.21873/invivo.13030 VO 36 IS 6 A1 JINAH CHU A1 MIN-KYUNG YEO A1 SANG HWA LEE A1 MI YEON LEE A1 SEOUNG WAN CHAE A1 HYUN-SOO KIM A1 SUNG-IM DO YR 2022 UL http://iv.iiarjournals.org/content/36/6/2890.abstract AB Background/Aim: The prognostic value of programmed death ligand-1 (PD-L1) expression in triple-negative breast cancer (TNBC) has not been sufficiently investigated. In this study, we examined whether PD-L1 expression status is associated with clinicopathological features and outcomes of patients with TNBC. Patients and Methods: Immunostaining for PD-L1 SP142 was performed on tissue microarrays containing 132 TNBC samples. High PD-L1 expression was defined as ≥10% of the tumor area occupied by PD-L1-expressing cells. Results: Thirty-five (26.5%) patients showed high PD-L1 SP142 expression on immune cells (ICs). High IC PD-L1 expression was significantly correlated with smaller tumor size (p=0.030), absence of lymphovascular invasion (p=0.024), and fewer lymph node metastases (p=0.002). Multivariate survival analysis revealed that high IC PD-L1 expression independently predicted better disease-free survival (DFS) of TNBC patients. Conclusion: High PD-L1 SP142 expression on ICs was significantly associated with favorable clinicopathological parameters and better outcomes in patients with TNBC. Our observations suggest that high IC PD-L1 expression can be used as an independent prognostic marker for predicting better DFS in patients with TNBC.