PD-L1 expression in nonclear-cell renal cell carcinoma.

Area of Science:

• Oncology
• Immunology
• Pathology

Background:

• The role of Programmed death ligand-1 (PD-L1) expression in non-clear cell renal cell carcinoma (non-ccRCC) remains unclear.
• Understanding PD-L1 expression is crucial for predicting clinical outcomes in non-ccRCC patients.

Purpose of the Study:

• To investigate PD-L1 expression in various subtypes of non-ccRCC.
• To determine the association between PD-L1 expression and clinical outcomes, including time to recurrence (TTR) and overall survival (OS).

Main Methods:

• Analyzed formalin-fixed paraffin-embedded (FFPE) specimens from 101 non-ccRCC patients using immunohistochemistry.
• Assessed PD-L1 expression on both tumor cell membranes and tumor-infiltrating mononuclear cells (TIMC).
• Correlated PD-L1 expression levels with clinico-pathological characteristics and patient outcomes (TTR and OS).

Main Results:

• PD-L1 positivity in tumor cells was observed in 10.9% of patients and significantly associated with higher stage, higher grade, and shorter OS (P < 0.001).
• PD-L1 positivity in TIMC was found in 56.4% of patients, showing a trend towards shorter OS (P = 0.08).
• PD-L1 positivity in both tumor cells and TIMC was linked to shorter TTR (P = 0.02 and P = 0.03, respectively).

Conclusions:

• PD-L1 expression in non-ccRCC is associated with adverse clinical outcomes.
• PD-L1 positivity in tumor cells is a significant indicator of higher tumor stage and grade in non-ccRCC.
• Further research into PD-L1 targeted therapies may be warranted for non-ccRCC.