Expression of PD-1 and PD-L1 in Breast Carcinoma: Research Protocol for a Cohort Study

Abstract

Introduction: Breast cancer is the most common malignant tumour and the leading cause of cancer-related death in women is breast cancer. The Immunohistochemistry (IHC) method utilised antigens and antibodies to interact to identify cellular or tissue constituents (antigens). This research has been employed as a diagnostic tool for specific cancers. When Programmed Cell Death Ligand 1 (PD-L1) binds to Programmed Cell Death 1 (PD-1), it suppresses the cellular immune response by killing and depleting T-cells. Monoclonal antibodies that block the PD-1/ PD-L1 pathway have shown promise as a treatment strategy currently being tested in human cancer trials. Need for the study: Breast cancer is a global issue, and PDL1 expression is emerging as a promising biomarker for breast cancer prognosis. It can provide valuable information treatment planning. Aim: The current study aims to examine the expression of PD-1 and PD-L1 in breast cancer using IHC in all subgroups of breast cancer patients. Both tests can serve as a biomarkers to guide immunotherapeutic interventions, improving prognosis, and correlating with other clinicopathological individual parameters such as age, tumour size, distant metastasis, lymph node involvement, Estrogen Receptor (ER) and Progesterone Receptor (PR) status, Her2neu expression, histological type, and TNM stage. Materials and Methods: This will be a two-year cohort study conducted in the Department of Pathology, Jawaharlal Nehru Medical College (JNMC), Maharashtra, India. The study will include 70 specimens from all cases with a histopathological diagnosis of breast cancer. The Nottingham variant of the Bloom-Richardson Grading System will be used to determine the histological grade of the tumour, and immunostaining for PD-1 and PD-L1 will be performed to evaluate their protein expression.