Impact of Microscopic Wall Invasion of the Renal Vein or Inferior Vena Cava on Cancer-specific Survival in Patients with Renal Cell Carcinoma and Tumor Thrombus: A Multi-institutional Analysis from the International Renal Cell Carcinoma-Venous Thrombus Consortium

Abstract

Background

Microscopic vein invasion (MVI), with local destruction and invasion of the endothelium by tumor, is of controversial predictive value in renal cell carcinoma (RCC).

Objective

To assess the impact of venous extension and wall invasion in RCC on survival.

Design, setting, and participants

Data for 1023 RCC patients with vena cava thrombus treated with radical nephrectomy and complete tumor thrombectomy were collected within a prospectively maintained international consortium (1995–2012).

Outcome measurements and statistical analysis

The Kaplan-Meier method and univariable and multivariable Cox regression analyses were used to assess the impact of MVI on cancer-specific survival (CSS). The main two variables of interest were microscopic renal vein wall invasion (MRVI) and microscopic vena cava wall invasion (MVCI).

Results

MRVI was found in 725 cases (70.9%) and MVCI in 230 (22.5%). Patients with MRVI had larger tumors (p=0.005), longer hospital stay (p<0.001), higher clinical stage 0.039), higher Fuhrman grade (p=0.028), and more frequent fat invasion. Presence of MVCI was associated with larger tumors (p<0.001), longer hospital stay (p<0.001), higher clinical stage (p<0.001), lymph node involvement (p=0.045), higher Fuhrman grade (p<0.001), and higher thrombus level (p<0.001). With median follow-up of 52 mo, overall 5-yr CSS was 57.4%. Multivariable analysis showed that presence of MRVI was an independent factor related to CSS (hazard ratio 2.24, 95% confidence interval 1.24–3.59, p=0.006). The main limitation was the inability to report MVI percentages.

Conclusions

Patients with MRVI experience significantly worse survival outcomes after radical nephrectomy and tumor thrombectomy. Consideration of MRVI at final pathology is appropriate to improve decision-making for risk-adapted follow-up.

Patient summary

The behavior of locally advanced renal cell carcinoma (RCC) depends on clinical and pathologic factors. Analysis revealed that RCC patients with microscopic renal vein wall invasion experience significantly worse cancer-specific survival.