NECTIN4, TROP2 and PDL1 in Breast Cancer: Immunohistochemical Profiling and Clinical Associations

Aims To systematically analyze the immunohistochemical expression patterns of NECTIN4 and TROP2 in breast cancer, their clinicopathological correlations, and associations with PDL1 status. Materials and methods NECTIN4 (H-score), TROP2 (H-score), and PDL1 (Combined Positive Score, CPS) expression were evaluated in 112 surgically resected breast carcinomas using validated immunohistochemical assays. Associations with clinicopathological variables were analyzed using Spearman's correlation, χ 2 tests, and Mann-Whitney U tests. Results NECTIN4 exhibited moderate-to-high expression (H-score ≥ 100) in 78% of specimens, predominantly localized to the cell membrane, and showed a significant positive correlation with HER2 positivity (ρ = 0.27, P < .01). TROP2 displayed near-ubiquitous moderate-to-high expression (96%) and exhibited higher expression in the triple-negative breast cancer (TNBC) subtype. Notably, there was no significant correlation between NECTIN4 or TROP2 and PDL1 co-expression. Conclusions This study provides a comprehensive characterization of NECTIN4 and TROP2 expression in breast cancer, suggesting their potential as biomarkers. The observed associations with PDL1 and clinicopathological features may inform future investigations into their biological roles and clinical relevance.