Tumor-derived circulating endothelial cells as a biomarker in locally advanced and metastatic clear cell renal cell carcinoma

Renal cell carcinoma accounts for 2-3% of the malignancies in adults worldwide. 70-80% of the malignant solid lesions of the kidney are clear cell renal cell carcinomas (ccRCC). With ccRCC being relatively chemotherapy and radiotherapy resistant, targeted therapies are the therapies of choice in ccRCC when treatment is indicated. No sensitive biomarkers are available to determine the response of these targeted therapies. Since all of the first-line targeted therapies exert anti-angiogenic effects, circulating endothelial cells (CECs) can fulfill a role in this need for biomarkers. CECs are endothelial cells that are shed from the vessel wall. Recently, we identified a marker (CD276) that can distinguish between CECs that originate from the normal vasculature (CD276-negative) and the tumor vasculature (CD276-positive) in patients. Also, studies have shown that 95-98% of the immunohistochemically stained ccRCC vasculature specimens are positive for CD276 and that diffuse vascular CD276-expression was associated with poor outcome. Therefore, we hypothesize that CD276-positive CECs can be of clinical value in patients with locally advanced metastatic ccRCC.

We hypothesize that CD276-positive CECs can be of clinical value in patients with locally advanced or metastatic ccRCC

- CD276-positive CEC count at baseline and after 4 weeks of VEGFR-TKI based therapy

- PFS at 12 months

Blood draw at baseline and after 4 weeks