Spatial multi-omics landscape of colorectal cancer macro- and micrometastases.

Colorectal cancer (CRC) metastases frequently recur due to minimal residual disease (MRD) and persistent micrometastases after therapy. Here, we performed spatial multimodal profiling using spot-level and high-resolution spatial transcriptomics, multi-regional whole-genome sequencing following laser-capture microdissection, and high-plex protein imaging to map 49 tumors from 19 patients, encompassing paired primary CRC and matched liver (CLiM) and lung (CLuM) metastases. Phylogenetic reconstruction revealed that liver micrometastases (CLiMi) arose from early clonal divergences and harbored a stem-like, quiescent state consistent with metastatic dormancy. Spatially, we uncovered distinct stromal barriers: macrometastases were encapsulated by myofibroblasts, whereas micrometastases were surrounded by immunosuppressive niches characterized by T cell exhaustion and distinct ligand-receptor signaling networks. Notably, we identified a CLiMi-specific six-gene signature associated with MRD status, disease-free survival, and chemotherapy resistance across multiple independent cohorts. These findings elucidate the spatial evolutionary landscape of CRC metastases and provide tissue-based spatially validated biomarkers for surveillance and therapeutic targeting.