The association between PD-1 / PD-L1 expression and clinicopathological features in sarcomatoid renal cell carcinoma.

Background: Sarcomatoid renal cell carcinoma (sRCC) accounts for about 4%-5% of all kidney cancers. Previous studies showed that PD-1 and PD-L1 expression was higher in sRCC compared to non-sRCC. In the present study, we aimed to investigate PD-1/PD-L1 expression and its association with clinicopathological features in sRCC.

Methods: The study included 59 patients diagnosed with sRCC between January 2012 and January 2022. The expression of PD-1 and PD-L1 in sRCC was detected by immunohistochemical staining, and its correlation with clinicopathological parameters was analyzed by χ2 test and Fisher exact test. Kaplan-Meier curves and log-rank tests were used to describe the overall survival (OS). The prognostic significance of clinicopathological parameters on OS was assessed by Cox proportional hazards regression analysis.

Results: Among the 59 cases, the positive expression of PD-1 and PD-L1 was 34 cases (57.6%) and 37 cases (62.7%), respectively. PD-1 expression was not significantly correlated with any parameters. However, PD-L1 expression was significantly correlated with tumor size and pathologic T stage. OS was shorter in the subgroup of patients with PD-L1-positive sRCC compared with the PD-L1-negative subgroup. There was no statistically significant difference in OS between PD-1-positive and negative subgroups. According to our study, the univariate and multivariate analysis indicated that pathological T3 and T4 was an independent risk factor in PD-1-positive sRCC.

Conclusion: We studied the relationship between PD-1/PD-L1 expression and clinicopathological characteristics in sRCC. The findings may provide valuable implications for clinical prediction.