Expression levels of PD-L1, a key protein involved in tumor cell survival, may predict response to standard first-line therapy with vascular endothelial growth factor (VEGF)-tyrosine kinase inhibitors (TKIs) in patients with metastatic clear cell renal cell carcinoma (mCCRCC), a new study published online ahead of print in the journal The Oncologist has shown.

VEGF-TKIs, including sunitinib, sorafenib, and pazopanib, are currently recommended for the first-line treatment of mCCRCC as these agents can improve survival when used alone and in combination with immunotherapy; however, up to 30% of patients do not respond to VEGF-TKI treatment and others develop resistance to these drugs.

“The VEGF-TKIs are essential for treating patients with metastatic renal cell carcinoma, but this treatment approach suffers from a lack of predictive markers,” said Heounjeong Go, MD, PhD, of University of Ulsan College of Medicine, Asan Medical Center, in Korea. 

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Therefore, researchers sought to evaluate the association between tumor PD-L1 expression levels and treatment outcomes in patients with mCCRCC treated with VEGF-TKI therapy. Researchers analyzed tumor samples from 91 patients for PD-L1 expression by immunohistochemical staining.

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Results showed that 17.6% of tumor samples were positive for PD-L1 expression and PD-L1 positivity was significantly associated with poor overall survival (P=0.038) and progression-free survival (P=0.013).

“As a predictor of treatment response and overall prognosis, PD-L1 expression may be helpful for determining the value of VEGF-TKI therapy in patients with mCCRCC,” Dr. Go wrote.


  1. Shin S-J, Jeon YK, Cho YM, et al. The association between PD-L1 expression and the clinical outcomes to vascular endothelial growth factor-targeted therapy in patients with metastatic clear cell renal cell carcinoma [published online ahead of print September 30, 2015]. Oncologist. doi: 10.1634/theoncologist.2015-0151.