Neurotrophic Receptor Tyrosine Kinase 3 as a Prognostic Biomarker in Breast Cancer Using Bioinformatic Analysis

Background and Objectives: Neurotrophic receptor tyrosine kinase 3 (NTRK3) is a member of the tropomyosin receptor kinase family of receptor tyrosine kinases, which play a crucial role in neural development. However, owing to the limited number of studies about NTRK3 and cancer, we aimed to investigate NTRK3 as a potential prognostic marker for breast cancer (BC). Materials and Methods: We conducted a comprehensive analysis of NTRK3 expression in BC using the Tumor Immune Estimation Resource, Gene Expression Profiling Interactive Analysis 2, and Kaplan-Meier Plotter databases. We also explored the association between NTRK3 expression and tumor-infiltrating immune cells. Results: Low NTRK3 expression showed poorer prognosis in BC, as well as with T stage, pathology, and the Luminal subtype. In BC (BRCA), NTRK3 was positively correlated with CD4+ T cell, CD8+ T cell, macrophage, and neutrophil infiltration. Conclusions: These results suggest that NTRK3 may serve as a prognostic biomarker and provide novel insights into tumor immunology in BC. Therefore, NTRK3 represents a potential diagnostic and therapeutic target for BC treatment.