Programmed death-ligand 1 (PD-L1) expression in  malignant and benign cervical and breast cancers:

Victor Ekundina; Emmanuel A. Omon; Charlize  Erilim; Moses A. Hamed

doi:10.46829/hsijournal.2025.6.7.1.1067-1074

Victor Ekundina Department of Medical Laboratory Science, College of Medicine and Health Sciences, Afe Babalola University, Ado-Ekiti, Ekiti State, Nigeria.
Emmanuel A. Omon Department of Medical Laboratory Science, College of Medicine and Health Sciences, Afe Babalola University, Ado-Ekiti, Ekiti State, Nigeria
Charlize Erilim Department of Medical Laboratory Science, College of Medicine and Health Sciences, Afe Babalola University, Ado-Ekiti, Ekiti State, Nigeria.
Moses A. Hamed Department of Medical Laboratory Science, College of Medicine and Health Sciences, Afe Babalola University, Ado-Ekiti, Ekiti State, Nigeria.

DOI: https://doi.org/10.46829/hsijournal.2025.6.7.1.1067-1074

Keywords: Cervical cancer, breast cancer, PD-L1, immunotherapy, immunohistochemistry, HPV

Abstract

Background: Programmed death-ligand 1 (PD-L1) expression has become a valuable biomarker for guiding immunotherapy selection in various cancers, including breast and cervical malignancies.
Objective: This study aimed to investigate the immunohistochemical expression of PD-L1 in malignant and benign breast and cervical cancers.
Methods: This retrospective study involved the analysis of 40 formalin-fixed paraffin-embedded tissue blocks, with 20 blocks from breast cancer patients and 20 from cervical cancer patients. Immunohistochemical analysis was performed via the avidin-biotin immunoperoxidase method to detect PD-L1 expression. The expression was assessed using a semi-quantitative method, grading the staining intensity and the percentage of stained cells per field. The stained sections were observed under a Leica microscope (Leica DM750, Switzerland) connected to
a digital camera (Leica ICC50).
Results: PD-L1 expression was greater in cervical cancer than in breast cancer. In breast cancer, benign cases mostly presented negative PD L1 expression, with a mean percentage reactivity (MPR) of 14.8%, whereas malignant cases presented mild expression, with an MPR of 46.4%. In cervical cancer, benign cases were mainly negative, with an MPR of 18.4%, whereas malignant cases displayed mild to moderate PD-L1 expression, with an MPR of 71.3%.
Conclusion: PD-L1 expression was more pronounced in cervical cancer than in breast cancer. The elevated levels of PD-L1 in cervical cancer suggest that this type of cancer may be more responsive to immunotherapeutic interventions targeting the PD-L1 pathway compared to breast cancer. Recognising these differences is crucial for tailoring treatment plans and implementing personalised medicine strategies for each specific cancer type.