Genomic alterations and treatment define spatiotemporal patterns of glioblastoma recurrence.

Abstract

The surgical margin is the primary site of glioblastoma recurrence, yet its molecular features remain poorly characterized. We performed histology-guided sampling and single-cell spatial transcriptomics of surgical margin and adjacent recurrent tumor regions, with matched primary tumors from 40 patients. The surgical margin constituted a distinct wound-healing microenvironment in the post-treatment setting. We also identified malignant states with pronounced mesenchymal transcriptomic and histological features that were enriched at the surgical margin and defined a "stromal" subtype. Patients who transitioned to this subtype at recurrence were characterized by early TP53 mutation, sustained proliferation during adjuvant temozolomide treatment, and shorter survival. Conversely, patients with TP53-wild-type tumors recurring during temozolomide treatment transitioned toward the mesenchymal subtype, with increased p53 pathway activity and reduced proliferation. Functional validation showed TP53 loss-of-function increased temozolomide resistance in a patient-derived glioblastoma model. Our findings identify distinct glioblastoma recurrence trajectories linked to genomic context, treatment exposure, and clinical outcomes.