Prognostic significance of venous tumour thrombus consistency in patients with renal cell carcinoma (RCC)

Objectives To identify the prognostic impact of venous tumour thrombus (VTT) in locally advanced renal cell carcinomas (RCCs). To further differentiate the clinical course of patients with VTT who have similar clinicopathological characteristics. Patients and Methods We determined the VTT consistency (solid vs friable) in a retrospective cohort of 200 patients with RCC who had undergone nephrectomy between 1994 and 2011. We examined the correlation of VTT consistency in these patients with clinical and pathological variables. Results A total of 65% of the patients had solid VTT and 35% had friable VTT, which has a significantly lower amount of cell-cell adhesion molecules and connective tissue than solid VTT. We found that friable VTT was associated with advanced pT stage, higher VTT level, papillary RCC subtype and a lower age. Patients with friable VTT had a significantly shorter median overall survival than those with solid VTT (29 vs 89 months), but VTT consistency was not found to be an independent predictor of patients' survival in the multivariate Cox analysis. We found that VTT consistency was an independent significant predictor of overall survival in patients without evidence of distant and nodal metastases (N = 119). Conclusions The VTT consistency is caused by the tumour and not by different surgical handling. Friable VTT is an important adverse prognostic predictor of overall survival in patients with non-metastatic RCC.