Background: PD‑L1/PD‑1 molecules are known as important mediators in immune‑escape mechanisms of tumors. PD‑L1 is highly
expressed in various malignancies, including bladder cancer. However, the prognostic value of PD‑L1 in bladder cancer patients
Aim: To investigate the prognostic significance of PD‑L1 expression in tumor tissues of bladder cancer patients.
Subjects and Methods: RNA was isolated from FFPE tumor tissues of 48 bladder cancer patients using the monophasic phenol
and guanidine isothiocyanate method. Total RNA was converted to cDNA and gene expression levels were analyzed by qRT‑PCR.
The differential expression levels of the PD‑L1 gene between tumor grade and cancer stage groups were analyzed by independent
student’s t‑test and one‑way ANOVA.
Results: Statistically significantly increased PD‑L1 expression was observed in the high‑grade tumor group (p < 0.05). No significant
difference in PD‑L1 expression was found among pTa, pT1, and pT2 groups. In addition, the difference in overall survival was not
significantly different between groups.
Conclusion: The results showed that high PD‑L1 expression in bladder cancer was associated with tumor aggressiveness and
grade. Despite the inability of the qRT‑PCR to show the PD‑L1 expression at different locations of tumor tissue, evaluation of PD‑L1
mRNA expression by qRT‑PCR, which is a highly sensitive and specific assay, appears to be a robust approach. Furthermore, these
findings may contribute to a rationale for recommending anti‑PD‑L1 immunotherapy as an alternative to standard therapy for bladder
cancer patients who are most likely to benefit from it.