Objective To explore the expression and clinical significance of tumor infiltrating lymphocytes in luminal breast cancer.

Methods The original expression data of breast cancer and luminal breast cancer in the Cancer Genome Atlas(TCGA) were analyzed, and the pathway enrichment analysis and prognostic analysis were performed to screen prognostic protective factors of luminal breast cancer.

Results By analyzing the original expression data of breast cancer and luminal breast cancer in TCGA database, 1 003 up-regulation genes and 1 679 down-regulation genes were screened out.The results of further GO analysis of prognostic protective genes in luminal breast cancer recurrence group indicated that the lymphocytes activation and T cell receptor-related pathways were inhibited, while the resulst of KEGG pathway enrichment analysis indicated that the T cell differentiation, antigen presentation and T cell receptor signaling pathways were also significantly inhibited.On the basis of the above pathway selection, TUNAR gene was further screened as a protective prognostic factor that was positively correlated with MHC-Ⅰ molecules and negatively correlated with PD-L1.The gene correlation analysis and prognostic correlation analysis showed that TUNAR might play a role as a prognostic protective factor in luminal breast cancer by affecting lymphoimmune-related pathways.

Conclusions TUNAR is significantly low expressed in the tissue samples of patients with luminal breast cancer, and may play a protective role in the prognosis of patients with luminal breast cancer by affecting the lymphatic immune related pathways.