The paper describes a study published in Nature Cancer that utilized multiplexed ion beam imaging (MIBI) and longitudinal profiling to identify biomarkers for immunotherapy response in metastatic triple-negative breast cancer. By analyzing 103 patients from the TONIC trial, researchers developed SpaceCat, an open-source pipeline that extracts over 800 spatial features from the tumor microenvironment. The study found that on-treatment metastatic biopsies were significantly more predictive of patient outcomes than primary tumors or baseline samples. High-performing multivariate models revealed that immune diversity, T cell infiltration at tumor borders, and PDL1 expression on myeloid cells are critical indicators of response. Ultimately, the research emphasizes that spatiotemporal dynamics are essential for understanding how metastatic lesions evolve and respond to immune checkpoint inhibition.

References:

• Greenwald N F, Nederlof I, Sowers C, et al. Temporal and spatial composition of the tumor microenvironment predicts response to immune checkpoint inhibition in metastatic TNBC[J]. Nature cancer, 2026: 1-16.