Spatiotemporal evolution of the ccRCC microenvironment links intra-tumoral heterogeneity to immune escape

BackgroundIntratumoral heterogeneity (ITH) is a hallmark of clear cell renal cell carcinoma (ccRCC) that reflects the trajectory of evolution and influences clinical prognosis. Here we seek to elucidate how ITH and tumor evolution during immune checkpoint inhibitor (ICI) treatment can lead to therapy resistance. MethodsHere, we spatiotemporally profiled the genomic and immunophenotypic characteristics of 29 ccRCC patients, including pre- and post-therapy samples from 17 ICI treated patients. Deep multi-regional whole exome and transcriptome sequencing were performed on 29 patients at different time points before and after ICI therapy. T cell repertoire was also monitored from tissue and peripheral blood collected from a subset of patients to study T cell clonal expansion during ICI therapy. ResultsAngiogenesis, lymphocytic infiltration, and myeloid infiltration varied significantly across regions of the same patient, potentially confounding their utility as biomarkers of ICI response. Elevated ITH associated with a constellation of both genomic features (HLA LOH, CDKN2A/B loss) and microenvironmental features, including elevated myeloid expression, reduced peripheral T cell receptor (TCR) diversity, and putative neoantigen depletion. Hypothesizing that ITH may itself play a role in shaping ICI response, we derived a transcriptomic signature associated with neoantigen depletion that strongly associated with response to ICI and targeted therapy treatment in several independent clinical trial cohorts. ConclusionsThese results argue that genetic and immune heterogeneity jointly co-evolve and influence response to ICI in ccRCC. Trial registrationWe completed a single-arm pilot study at Memorial Sloan Kettering Cancer Center (MSKCC; ClinicalTrials.gov identifier NCT02595918) to examine the safety and feasibility of neoadjuvant nivolumab in patients with localized RCC.