PD-L1 Expression Reveals Significant Association With Squamous Differentiation in Upper Tract Urothelial Carcinoma

The Prevalence and Prognostic Role of PD-L1 in Upper Tract Urothelial Carcinoma Patients Underwent Radical Nephroureterectomy: A Systematic Review and Meta-Analysis

“…If PD-L1 levels in tumor cells were linked to clinical and pathological features, the PD-L1 inhibitors would inhibit the tumor biology, such as invasion, recurrence, and metastasis, etc. In the study, PD-L1 was related to UTUC in T stage and tumor grade, and similar findings have been indicated in both UTUC and other types of tumors (23,24,32,33). Results indicated that PD-L1 could not promote the LVI of UTUC, while great heterogeneity existed in the five studies (13,(15)(16)(17)24).…”

“…Hayakawa et al reported that positive PD-1 in the tumor nest was related to CSS and RFS (27). Two studies reported that PD-1 in tumor-infiltrating lymphocytes (TILs) and PD-L1 in tumor cells were linked with UTUC prognosis (15,23). The metaanalysis only pooled the results from eight studies reporting PD-L1 levels from tumor cells and we found that higher PD-L1 levels had association with CSS rather than OS.…”

“…Results of the cumulative meta-analysis indicated that the 95% CIs narrowed as the pooled results gradually moved near the null. In the meta-analysis, five studies reported a high expression rate (>20%) of PD-L1 (15,17,(23)(24)(25), which provided rationality to apply immunotherapy in such cancers. Furthermore, the great variation in the prevalence might be ascribed to the different IHC strategies across studies, including the different cutoff values and diverse primary antibody species, etc.…”

“…We excluded records for the following reasons: article types or not relevant topics (n = 188), studies had few study samples (≤50) or follow-up duration less than 12 months (n = 4), not in English (n = 9), or insufficient survival data (n = 15). Finally, we included eight retrospective cohort studies (1,406 individuals) (13)(14)(15)(16)(17)(23)(24)(25) in the study (shown in Figure 1).…”

“…All the studies adopted immunohistochemistry (IHC) to analyze the level of PD-L1 in tumor tissues. Notably, the intensity of PD-L1 in IHC was only mentioned in four studies (14,(23)(24)(25), while none of them reported neither the mean/median intensity nor its linear correlation with the outcomes. The NOS grades indicated that all studies had high qualities (Supplementary Table 2).…”