BackgroundTriple-negative breast cancer (TNBC) is a heterogeneous disease lacking approved targeted therapies and standardized treatment regimens. Among its molecular subtypes, luminal androgen receptor-positive (LAR+) TNBC is characterized by reduced proliferative activity and a lower sensitivity to chemotherapy.
The tumor immune microenvironment (TIME) plays a critical role in shaping treatment responses; however, its spatial organization and cellular composition in LAR+ TNBC remain poorly understood.MethodsIn this exploratory study, we performed multiplex immunofluorescence analysis to characterize 18 immune and tumor cell subtypes in paired pre- and post-neoadjuvant therapy (NAT) samples from small, exploratory cohort of patients with LAR+ TNBC, stratified by pathological complete response (pCR). We assessed immune cell composition, expression of exhaustion markers, and spatial relationships among cellular populations to explore TIME features associated with different pathological responses.ResultsPatients who achieved pCR displayed higher pre-treatment densities of specific immune subsets, including CD20+PD-1+, CD4+FOXP3+, and CD8+PD-1+TIM3+ cells, consistent with an immune-enriched microenvironment.
Spatial analyses revealed distinct patterns between Responders (Resp) and Non-Responders (NoResp). In Resp, tumor cells (PANCK+) were initially located closer to PD-L1–expressing tumor cells (PANCK+PD-L1+), with this proximity decreasing after NAT.
Frontiers in Immunology published a clinical update in Infectious Disease on 22 May 2026.
The item focuses on Spatial organization of the tumor immune microenvironment in LAR+ triple-negative breast cancer.
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