Limited benefit of targeted molecular therapy for inferior vena cava thrombus associated with renal cell carcinoma.

Abstract

The clinical benefit of targeted molecular therapy (TMT) for an inferior vena cava (IVC) tumor thrombus associated with renal cell carcinoma (RCC) is unclear. The aim of the present study was to assess the change in IVC thrombus height during TMT and to identify the factors associated with the effect of TMT on an IVC thrombus in RCC patients. The present study retrospectively analyzed 21 patients with an IVC thrombus who were treated with TMT at our hospital. Thrombus height and level before and after TMT were assessed using CT or MRI. Furthermore, we examined the factors associated with the effect of TMT on the IVC thrombus. The tumor thrombus level before TMT was I in 2 patients (10%), II in 10 (47%), III in 4 (19%), and IV in 5 (24%). Following TMT, the tumor thrombus height decreased in 16 patients (76%), and the mean decrease was 17mm. The tumor thrombus height increased in 5 patients (24%), and the mean increase was 30mm. The tumor thrombus level decreased in 4 patients (19%), remained stable in 15 patients (71%), and increased in 2 patients (10%). We found that the clinical nodal stage (p=0.025) was significantly associated with and the serum neutrophil count (p=0.067) tended to be associated with the reduction in the IVC thrombus. The clinical benefit of TMT for an IVC thrombus associated with RCC is limited.