BackgroundCancer-associated fibroblasts (CAFs) within the tumor microenvironment (TME) are critical for immune suppression by restricting immune cell infiltration in the tumor stromal zones from penetrating tumor islands and changing their function status, particularly for CD8+ T cells. However, assessing and quantifying the impact of CAFs on immune cells and investigating how this impact is related to clinical outcomes, especially the efficacy of immunotherapy, remain unclear.Materials and methodsThe TME was characterized using immunohistochemical (IHC) analysis using a large-scale sample size of gene expression profiles. The CD8+ T cell/CAF ratio (CFR) association with survival was investigated in The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) lung cancer cohorts. The correlation between CFR and immunotherapeutic efficacy was computed in five independent cohorts. The correlation between CFR and objective response rates (ORRs) following pembrolizumab monotherapy was investigated in 20 solid tumor types. To facilitate clinical translation, the IHC-detected CD8/α-SMA ratio was applied as an immunotherapeutic predictive biomarker in a real-world lung cancer cohort.ResultsCompared with normal tissue, CAFs were enriched in cancer tissue, and the amount of CAFs was overwhelmingly higher than that in other immune cells. CAFs are positively correlated with the extent of immune infiltration. A higher CFR was strongly associated with improved survival in lung cancer, melanoma, and urothelial cancer immunotherapy cohorts. Within most cohorts, there was no clear evidence for an association between CFR and programmed death-ligand 1 (PD-L1) or tumor mutational burden (TMB). Compared with TMB and PD-L1, a higher correlation coefficient was observed between CFR and the ORR following pembrolizumab monotherapy in 20 solid tumor types (Spearman’s r = 0.69 vs. 0.44 and 0.21). In a real-world cohort, patients with a high CFR detected by IHC benefited considerably from immunotherapy as compared with those with a low CFR (hazard ratio, 0.37; 95% confidence interval, 0.19–0.75; p < 0.001).ConclusionsCFR is a newly found and simple parameter that can be used for identifying patients unlikely to benefit from immunotherapy. Future studies are needed to confirm this finding.

Background Predictive markers for guidance and monitoring of immunotherapy in lung squamous cell carcinoma (LSCC) are an interesting topic but have yet to be fully explored. A primary characteristic of LSCC is tumor necrosis that results in extensive immune suppression in patients. We sought to assess whether tumor necrosis or cavity on baseline CT could effectively predict the efficacy of immune checkpoint inhibitors (ICIs) in advanced LSCC. Methods Advanced LSCC cases undergoing pre-treatment chest CT imaging and receiving ICIs were retrospectively collected. All CT images were reviewed by an independent chest radiologist blinded to any previous diagnosis to confirm morphological alterations in necrosis or cavity. We performed Logistic regression and developed Cox proportional hazards models to assess the predictive performance of baseline necrosis or cavity characteristics in advanced LSCC. Survival estimates were observed using Kaplan–Meier curves. Results Ninety-three patients were eligible for analysis, predominantly consisting of patients with ECOG performance status of 0 or 1 (97.8%), male patients (95.7%), and heavy smokers (92.5%). Intrapulmonic necrosis or cavity on CT scan was present in 52.7% of all patients. Generally, the objective response rate (ORR) in patients with necrosis or cavity to ICI treatment was significantly worse versus those without (30.6% vs 54.5%, p = 0.020), with the subgroup ORRs as follows: ICI monotherapy (necrosis vs non-necrosis: 10.0% vs 36.8%, p =0.047) and ICI combination therapy (44.8% vs 68.0%, p =0.088). Multivariable analysis identified intrapulmonic necrosis or cavity at baseline as a major risk factor for advanced LSCC (HR 4.042, 95% CI1.149–10.908, p = 0.006). Multivariate Cox analysis showed that baseline necrosis or cavity and ICI monotherapy were unfavorable factors for progression-free survival (HR 1.729; 95% CI1.203–2.484, p =0.003). Conclusion LSCC patients with intrapulmonic cavity or necrosis on baseline CT scan may respond poorly to anti-PD-(L)1-treatment, monotherapy and combination therapy alike.

No abstract

9536 Background: Cancer-related fibroblasts (CAFs) are important components of the tumor microenvironment (TME) and play a key role in tumor progression. There is growing evidence that CAF levels in tumors are highly correlated with treatment response and prognosis. However, the effect of CAFs on immunotherapy response remains unknown. Methods: RNA-seq and clinical data were downloaded from TCGA and GEO. The SVA package ComBat function was used to remove batch effects. The ssGSEA algorithm was used to assess the level of cell infiltration in each sample. OS (overall survival) and DFS (disease free survival) were analyzed using the Kaplan–Meier method. GO enrichment analysis was used to assess the biological processes of subgroup differential genes. The Tumor Immune Dysfunction and Exclusion (TIDE) algorithm and subclass mapping were used to predict the clinical response to immune checkpoint blockade. Results: We evaluated the infiltration abundance of 24 types of immune cells and fibroblasts in 1768 NSCLC samples and found that almost all IMFRs (immune cells / fibroblasts) are beneficial to the prognosis. This phenomenon is called “CAFs-mediated immune resistance pattern (CMIRP)”. We evaluated the infiltration abundance of 24 types of immune cells and fibroblasts in 1768 NSCLC samples and found that almost all IMFRs (immune cells / fibroblasts) are beneficial to the prognosis. This phenomenon is called “CAFs-mediated immune resistance pattern (CMIRP)”. The prognosis according to CD8+ T cells was not strong, but CD8+ T cells / fibroblasts (CFR) were significant protective prognostic factors [n = 1588; hazard ratio (HR), 0.66; 95% confidence interval (CI), 0.56–0.78; P < 0.001]. Multivariate analysis revealed that the CFR was an independent prognostic biomarker. The TCGA pan-cancer cohort confirmed the widespread presence of CMIRP in cancer. We further defined the CFR high and CFR low subgroups. CFR high samples were enriched with immune activation pathways including T cell activation, cytolysis, and antigen presentation, while CFR low was associated with immunosuppression including activation of transforming growth factor β, epithelial-mesenchymal transition, and angiogenesis pathways. Finally, we combined TIDE and submap to speculate that CFR is a potential prognostic marker of immunotherapy for NSCLC. Conclusions: We proposed the term “CMIRP” to shed light on a more accurate assessment of immune status. CFR is a potential marker for prognosis and predictive efficacy of immunotherapy in NSCLC.