PDL-1 and PDL1 expressions in clear cell renal cell carcinoma (ccRCC) of metastatic patients with sunitinib first-line treatment.

e14002 Background: Anti vascular growth epithelial factor (VEGF) therapies are currently used in first line of metastatic ccRCC, but some patients are inherently resistant to these treatments. Immunotherapy based on disruption of immune checkpoints, such as Programmed Death Ligand 1 (PD-L1) and Programmed Death 1 (PD-1), has been showed promising results. Interaction between PD-L1 and PD-1 down-regulates antitumor activity and could be involved in resistance to anti-VEGF therapies Methods: In this study, we assessed PD-L1 and PD-1 expressions by immunohistochemistry in primary ccRCC of metastatic patients with sunitinib first-line treatment. From 2 centers, 92 patients were restrospectively included and clinical data were collected with a median follow up of 22 months after sunitinib introduction. PD-L1 immunostaining was evaluated on the highest Fuhrman grade areas (n = 92) and PD-1 on the most inflammatory territory when the corresponding block was available (n = 47). PD-L1 and PD-1 were considered over...