biostudies-literatureLi ZNatural Science Foundation of Hebei ProvenienceHealth Commission of Hebei ProvinceDepartment of Education of Hebei ProHebei Provincial Key Research ProjectsHebei Province Outstanding youth fund40958https://www.ebi.ac.uk/biostudies/studies/S-EPMC12635151biostudies-literatureUnknown15(1)Breast cancer (BC) is the most common malignancy among women, with its progression and prognosis significantly influenced by the tumor microenvironment (TME). Age-related differences in TME composition lead to distinct tumor behaviors: young patients (≤ 40 years) exhibit aggressive tumors, while elderly patients (> 70 years) experience immunosenescence and reduced therapy responses. We performed single-cell RNA sequencing (scRNA-seq) analysis on tumors from 10 breast cancer patients (5 ≤ 40 years, 5 ≥ 70 years), encompassing 33,664 high-quality cells. After cell annotation and batch correction, malignant epithelial cells were identified using inferCNV. We applied pseudotime trajectory analysis, pathway enrichment, and cell-cell communication profiling to investigate age-specific TME dynamiScientific reportsSingle-cell RNA sequencing reveals age-related heterogeneity in the tumor microenvironment of breast cancer patients.PMC12635151H2022206418No.BJ2025056No.22372409DZF202502320240643CXZZBS2020111Kou SLi ZFeng JAn MLiu BYu JShang FZhao ZfalseSingle-cell RNA sequencing reveals age-related heterogeneity in the tumor microenvironment of breast cancer patients.Breast cancer (BC) is the most common malignancy among women, with its progression and prognosis significantly influenced by the tumor microenvironment (TME). Age-related differences in TME composition lead to distinct tumor behaviors: young patients (≤ 40 years) exhibit aggressive tumors, while elderly patients (> 70 years) experience immunosenescence and reduced therapy responses. We performed single-cell RNA sequencing (scRNA-seq) analysis on tumors from 10 breast cancer patients (5 ≤ 40 years, 5 ≥ 70 years), encompassing 33,664 high-quality cells. After cell annotation and batch correction, malignant epithelial cells were identified using inferCNV. We applied pseudotime trajectory analysis, pathway enrichment, and cell-cell communication profiling to investigate age-specific TME dynami2025-01-01T00:00:00Z2025 Nov2026-05-19T03:23:54.808Z2026-05-19T03:12:07.14ZS-EPMC126351514126646310.1038/s41598-025-24720-2