Nanoparticle-enhanced radiotherapy synergizes with PD-L1 blockade to limit post-surgical cancer recurrence and metastasis

Tumor recurrence after surgical resection is associated with a poor clinical outcome. Here the authors design a manganese dioxide-based nanosystem to increase response to radio-immunotherapy by relieving tumor hypoxia and targeting myeloid cells, showing reduced post-surgical cancer recurrence and metastasis. Cancer recurrence after surgical resection (SR) is a considerable challenge, and the biological effect of SR on the tumor microenvironment (TME) that is pivotal in determining postsurgical treatment efficacy remains poorly understood. Here, with an experimental model, we demonstrate that the genomic landscape shaped by SR creates an immunosuppressive milieu characterized by hypoxia and high-influx of myeloid cells, fostering cancer progression and hindering PD-L1 blockade therapy. To address this issue, we engineer a radio-immunostimulant nanomedicine (IPI549@HMP) capable of targeting myeloid cells, and catalyzing endogenous H2O2 into O-2 to achieve hypoxia-relieved radiotherapy (RT). The enhanced RT-mediated immunogenic effect results in postsurgical TME reprogramming and increased susceptibility to anti-PD-L1 therapy, which can suppress/eradicate locally residual and distant tumors, and elicits strong immune memory effects to resist tumor rechallenge. Our radioimmunotherapy points to a simple and effective therapeutic intervention against postsurgical cancer recurrence and metastasis.

Automated summary

Surgical resection often leads to tumor recurrence, impacting clinical outcomes. Novel nanosystem utilizing manganese dioxide shows promise in reducing cancer recurrence and metastasis post-surgery by targeting myeloid cells and relieving tumor hypoxia, ultimately enhancing response to radio-immunotherapy.