Programmed Cell Death Ligand 1 (PD-L1) Expression in Triple Negative Breast Cancer Cases in Benin City

Area of Science:

• Oncology
• Immunology
• Pathology

Background:

• Triple-negative breast cancer (TNBC) lacks targeted therapies due to absent cellular receptors.
• The programmed cell death 1/programmed cell death ligand 1 (PD-1/PD-L1) pathway is a key target for cancer immunotherapy, particularly in TNBC.

Purpose of the Study:

• To investigate the expression patterns of PD-L1 in triple-negative breast cancer cases in Benin City, Nigeria.
• To assess the potential of PD-L1 expression as a biomarker for immunotherapy in this population.

Main Methods:

• Retrospective analysis of formalin-fixed, paraffin-embedded TNBC tissue blocks.
• Immunohistochemistry staining for PD-L1 expression on tumor cells.

Main Results:

• PD-L1 expression was detected in 14.1% of 92 TNBC cases.
• Diffuse tumoral PD-L1 staining was observed in 30.8% of PD-L1 positive cases.
• PD-L1 expression showed a significant association with increasing age up to the fifth decade (p=0.030).

Conclusions:

• PD-L1 expression is present at a lower rate in TNBC cases in southern Nigeria.
• Approximately 14.1% of TNBC patients in this cohort may be candidates for immune checkpoint inhibitor therapy.
• Further PD-L1 testing and consideration of immunotherapy for indicated TNBC cases are recommended.