Prognostic significance of PD-L1 and PD-L2 in breast cancer

• Published in: Human pathology Vol. 47; no. 1; pp. 78 - 84
• Main Authors: Baptista, Mauricio Z., MD, PhD, Sarian, Luis Otavio, MD, PhD, Derchain, Sophie F.M., MD, PhD, Pinto, Glauce A., PhD, Vassallo, José, MD, PhD
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.01.2016; Elsevier Limited
• Subjects: Adult; Age Factors; Aged; B7-H1 Antigen - analysis; Biomarker; Biomarkers, Tumor - analysis; Breast cancer; Breast Neoplasms - chemistry; Breast Neoplasms - immunology; Breast Neoplasms - mortality; Breast Neoplasms - pathology; Breast Neoplasms - therapy; Cancer therapies; Disease-Free Survival; Female; Humans; Immunohistochemistry; Kaplan-Meier Estimate; Lung cancer; Lymphatic Metastasis; Middle Aged; Neoplasm Staging; Ovarian cancer; Pathology; PD-L1; PD-L2; Prognosis; Programmed Cell Death 1 Ligand 2 Protein - analysis; Receptors, Estrogen - analysis; Risk Factors; Skin cancer; Survival; Time Factors; Tissue Array Analysis; Tumor Burden; PD-L1; PD-L2; Biomarker; Breast cancer; Prognosis; Survival
• ISSN: 0046-8177; 1532-8392
• DOI: 10.1016/j.humpath.2015.09.006

Summary PD-L1 and PD-L2 constitute an important antitumor immune response. In breast cancer, their prognostic value is still to be defined. In this study, we investigate the correlation between PD-L1 and PD-L2 protein expressions with clinical and pathologic features and disease-free survival and overall survival. To assess PD-L1 and PD-L2 expressions, we conducted immunohistochemistry studies using a breast cancer tissue microarray encompassing a total of 192 breast cancer cases, stages I, II, and III, with detailed clinical and outcome data. PD-L1 expression was present in 56.6% (107/189), and PD-L2 expression was identified in 50.8% (97/191) of breast cancer cases. Younger age at diagnosis, lymph node positivity, negative estrogen receptor, and recurrence at distant sites were all associated with both PD-L1 and PD-L2 expressions. The presence of larger tumors was associated only with PD-L1 expression. In our study, PD-L1 expression was significantly associated with better overall survival ( P = .04) in breast cancer patients. Despite its association with poor clinical and pathologic features, PD-L1 expression emerges as a positive prognostic biomarker in breast cancer. This survival result might be due to the presence of a strong antitumor immune response leading to PD-L1 expression.