Abstract
BACKGROUND: Tumor-infiltrating lymphocytes (TILs) and tertiary lymphoid structures (TLSs) are prognostic markers in triple-negative breast cancer (TNBC). Our study analyzed the relationship between cluster of differentiation (CD)11c-positive dendritic cells (DCs) and TILs and TLSs to elucidate mechanisms of TIL influx. MATERIALS AND METHODS: Immunohistochemical staining for CD4, CD8, and CD11c in tissue microarrays from 681 patients with TNBC was performed. The proportions of TILs and TLSs were reviewed. Two additional TNBC gene expression datasets were used. RESULTS: CD11c expression showed a significantly positive correlation with the level of TILs and the number of CD4(+) and CD8(+) T-cells, as well as an abundance of TLSs. CD11C gene expression was also significantly correlated with expression of CD4, CD8, and genes related to TLSs in both datasets. CONCLUSION: We demonstrated a strong correlation of CD11c expression, which represents DCs, with TILs and TLSs in TNBC. Further investigation is warranted to identify therapeutic modalities that facilitate recruitment and activation of DCs.