PD-L1 Expression in Japanese Renal Cell Carcinoma Patients

Inclusion Criteria

• •1\. Written informed consent for this study. In the case obtaining written informed consent is difficult due to death, change of address, and so on, the opt-out consent is accepted by giving patients or their relatives notification regarding the usage of their clinical information and surgical samples for the research.
• •2\. Age at nephrectomy≧20 years
• •3.Patients with recurrent or metastatic RCC who have initiated first line treatment between 1 January 2010 and 31 December 2015, with representative FFPE of nephrectomy surgical specimen which are suitable for assessment of PD-L1 expression