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) presents significant management challenges due to a lack of specific cellular receptors, leading to higher morbidity and mortality.
• The programmed cell death 1/programmed cell death ligand 1 (PD-1/PD-L1) pathway is a key target for immunotherapy, particularly in TNBC.
• Understanding PD-L1 expression patterns is crucial for predicting treatment response in TNBC.

Purpose of the Study:

• To investigate the prevalence and patterns of PD-L1 expression in triple-negative breast cancer (TNBC) cases.
• To assess the potential for immune checkpoint inhibitor therapy in TNBC patients in Benin City.

Main Methods:

• A retrospective study was conducted over three years (2017-2019).
• PD-L1 immunostaining was performed on 92 diagnosed TNBC cases.
• Tumour and immune cell PD-L1 expression was analyzed.

Main Results:

• PD-L1 expression was detected in 14.1% (13 out of 92) of 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 occurs at a low rate in the studied TNBC population.
• Approximately 14.1% of TNBC patients in this cohort may be candidates for immune checkpoint inhibitor therapy.
• Age is a significant factor associated with PD-L1 expression in TNBC.