High NTRK2 protein expression levels may be associated with poorer prognosis of breast cancer patients.

Objective: Previous research has shown that the role of neurotrophic receptor tyrosine kinase 2 (NTRK2) in breast cancer (BRCA) remains ambiguous. To help elucidate this, we conducted a retrospective study to investigate the relationship between NTRK2 protein expression and BRCA.

Methods: The prognostic significance of NTRK2 protein expression patterns was assessed by performing immunohistochemistry assays on 131 BRCA tissues and 56 adjacent normal tissues in a retrospective study. Furthermore, the sensitivity to chemotherapeutic drugs was quantified by "pRRophetic" and the sensitivity to immunotherapy was estimated using The Cancer Immunome Atlas website.

Results: NTRK2 protein was expressed at significantly higher levels in BRCA samples compared with normal tissues. The data indicated that NTRK2 expression is an independent risk factor for BRCA patient prognosis. Additionally, the high NTRK2 group exhibited increased sensitivity to certain chemotherapy drugs and achieved higher scores for immune checkpoint blockade therapy compared with the low NTRK2 group.

Conclusions: Our study demonstrated that higher NTRK2 protein expression is related to a less favorable prognosis in BRCA patients, as well as to enhanced sensitivity to specific chemotherapy and immunotherapy drugs.