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.
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.
- 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.