Spatio-temporal mapping of immune cell dynamics during human sequential lymph node metastasis

Regional lymph node metastasis critically influences distant metastatic progression, anti-tumour immunity, and patient prognosis. This study systematically characterised immune cell dynamics across paired primary tumours, sentinel tumour-draining lymph nodes (S-TDLNs), and secondary axillary lymph nodes (ALNs) from treatment-naïve triple-negative breast cancer (TNBC) patients using integrated multi-omics approaches, including imaging mass cytometry, single-cell RNA sequencing, Visium and Xenium spatial transcriptomics, and multiplex immunofluorescence. Xenium profiling was performed on FFPE lymph node sections spanning different metastatic stages to resolve high-resolution spatial organisation, neighbourhood complexity, and immune cell co-localisation during sequential lymph node metastasis.