The PD-L1 Expression Among Triple-Negative Breast Cancer Patients in Universitas Sumatera Utara Teaching Hospital, Indonesia.

Background: The emerging role of precision medicine among in oncologic science is a potentially explorable area to solve long-standing implication of triple-negative breast cancer (TNBC)'s management, especially by identifying programmed cell death ligand-1 (PD-L1) in its population. Objective: To describe the PD-L1's expression among TNBC populations in our Indonesia-based centers. Methods: This descriptive study was conducted in the teaching hospitals of Universitas Sumatera Utara ranging from April 2019 to July 2020. Our investigation encompassed female individuals with histopathologically confirmed TNBC and complete medical record data, especially the status of PD-L1 expression to be reported in this study. We use Daco 22C3 antibodies to confirm the latter protein immunohistochemical positivity after thorough specimen preparation and staining. Results: This study included 60 females with TNBC of which 40 participants were issued in the final report. Our populations were dominated by middle-aged individuals (41-50 years old; 45%), and remarkable presentation of LVSI, angioinvasion, or lymph-node metastatic status. In PD-L1 expression status, our study reported that 45.0% patients were confirmed with confirmed PD-L1 positivity. Conclusion: PD-L1 expression among TNBC patients is concordant with the global report hence anti-PD-1-based treatment trial in Asia or even Indonesia region should be considered.