However, the unprecedented clinical activity and excellent safety profile of checkpoint inhibitors targeting programmed death-1 receptor and its ligand (PD-1/PD-L1) have galvanized the field and generated much enthusiasm to harness the power of immunotherapy in pursuit of cures in patients with advanced sarcomas.
We investigated this issue using genomically related, clonal subsets from the same methylcholanthrene-induced sarcoma: a highly immunogenic subset that is spontaneously eliminated in vivo by adaptive immunity and a less immunogenic subset that forms tumors in immunocompetent mice, but is sensitive to PD-1/PD-L1 blockade therapy.
Finally, we found that SARC-L1 is sensitive to several drugs commonly used to treat sarcoma and also susceptible to anti-PD-L1 monoclonal antibody therapy in vivo.
Our meta-analysis indicated that high PD-L1 expression is likely to be a negative factor for patients with sarcomas and that it predicts worse survival outcomes.
Expression and clinical association of programmed cell death-1, programmed death-ligand-1 and CD8<sup>+</sup> lymphocytes in primary sarcomas is subtype dependent.
In this review, we provide a brief overview of the mechanisms of action of immune checkpoint inhibitors and discuss the proposed biomarkers of therapy response, such as lymphocytic infiltration, intratumoral PD-L1 expression, and mutational load in sarcomas.
Stata 12.0 software was applied to calculate the strength of association between PD-L1 expression and sarcoma.In total, 14 articles containing 15 independent studies and 1,451 patients were included in this meta-analysis.