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The following is a summary of “PD-L1 expression in tumor and inflammatory cells is associated with favorable tumor features and favorable prognosis in muscle-invasive urothelial carcinoma of the bladder not treated by immune checkpoint inhibitors,” published in the April 2024 issue of Urology by Plage et al.

High PD-L1 expression is a key predictive marker for the response to immune checkpoint inhibitor (CPI) therapy in bladder cancer. However, the relationship between PD-L1 expression and the course of the natural disease remains uncertain. To address this gap, the researchers conducted a comprehensive analysis of PD-L1 expression in 2710 urothelial bladder carcinomas, including 512 patients who underwent radical cystectomy before the CPI therapy era.

The findings reveal that PD-L1 positivity in tumor cells increased significantly from low to high-grade tumors and was notably higher in muscle-invasive carcinomas. Surprisingly, within muscle-invasive tumors, PD-L1 positivity was associated with lower tumor stage, absence of lymph node metastasis, absence of lymphovascular invasion, and improved prognosis among patients who did not receive CPI therapy. Moreover, PD-L1 expression in inflammatory cells was strongly correlated with PD-L1 expression in tumor cells, and both were associated with positive p53 immunostaining.

The robust association between PD-L1 status and favorable tumor characteristics and better prognosis suggests a potential influence on the outcomes of CPI therapy studies in muscle-invasive bladder cancer. These findings underscore the importance of considering PD-L1 expression and its relationship with tumor features when evaluating the efficacy of CPI therapy in patients with bladder cancer. 

Source: bmcurol.biomedcentral.com/articles/10.1186/s12894-024-01482-z