Presurgical pazopanib for renal cell carcinoma with inferior vena caval thrombus: a single-institution study

The aim of this study was to investigate the clinical benefit of presurgical therapy with pazopanib in renal cell carcinoma (RCC) patients with a tumor thrombus extending to a high level in the vena cava. A retrospective review was performed for seven consecutive patients with RCC and tumor thrombus involving the vena cava above the hepatic vein (level 3-4, Mayo Clinic classification) treated with pazopanib without initial cytoreductive nephrectomy at our institution. The effect of pazopanib was assessed in terms of the primary site response, thrombus diameter, and height (before and after treatment) on computed tomography or MRI. The tumor thrombus level before the induction of pazopanib was 3 in one patient and 4 in the remaining six patients. After pazopanib, shrinkage of the primary site and thrombus diameter and length were observed in all patients except one (with a rhabdoid tumor). The mean decreases of primary tumor diameter, tumor thrombus diameter, and length were 14, 9, and 31 mm, respectively. The tumor thrombus level decreased in three (43%) patients and remained stable in the remaining patient. Our findings suggest that presurgical treatment with pazopanib may shrink the tumor thrombus and decrease the surgical invasiveness in RCC patients with a high-level tumor thrombus.