The Prognostic Impact of a Positive Vascular Margin on pT3 Clear Cell Renal Cell Carcinoma.

PURPOSE: We examined the impact of positive vascular margins in patients with pT3 clear cell renal cell carcinoma. MATERIALS AND METHODS: After excluding patients with nonvascular positive margins, metastasis, lymph node involvement, neoadjuvant therapy or nonclear cell histology, we identified 224 patients with venous tumor invasion through our institutional database from 1999 to 2013. Kaplan-Meier analysis and log rank tests were used to evaluate whether positive vascular margins were associated with progression-free survival or cancer specific survival. RESULTS: There were 41 patients (18%) with a positive vascular margin. Margin status was directly related to the level of invasion (p <0.0001). Compared to the negative vascular margin group the positive group had a significantly worse progression-free survival (p=0.01) but not cancer specific survival (p=0.3). Similarly the level of vascular thrombus invasion was significantly associated with worse progression-free survival (p=0.02) but not cancer specific survival (p=0.4). The 3-year progression-free survival was worst with inferior vena cava invasion and best with segmental/muscular venous branch invasion (54%, 95% CI 34-70 vs 76%, 95% CI 64-85). Among patients with only main renal vein thrombus, vascular margin status was not associated with progression-free survival (p=0.5) or cancer specific survival (p=0.2). CONCLUSIONS: In patients with pT3N0/XM0 clear cell renal cell carcinoma positive vascular margins are associated with risk of disease progression. However, the risk of relapse associated with positive vascular margins is driven by the extent of vascular thrombus invasion. These findings suggest that the clinical significance of vascular margin status as currently defined in pT3 clear cell renal cell carcinoma is minimal.