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

Nick W. Liu, James D. Wren, Emily Vertosick, Justin K. Lee, Nicholas E. Power, Nicole E. Benfante, Simon Y. Kimm, Manjit S. Bains, Daniel D. Sjoberg, Paul Russo, Jonathan A. Coleman

We examined the impact of positive vascular margins in patients with pT3 clear cell renal cell carcinoma. After excluding patients with non-vascular positive margins, metastasis, lymph node involvement, neoadjuvant therapy, or non-clear cell histology, we identified 224 patients with venous tumor invasion through our institutional database from 1999-2013. 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. Forty-one patients (18%) had 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 significantly worse progression-free survival (p=0.01), but not cancer-specific survival (p=0.3). Similarly, level of vascular thrombus invasion was significantly associated with worse progression-free survival (p=0.02), but not cancer-specific survival (p=0.4). Three-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). In patients with pT3N0/XM0 clear cell renal cell carcinoma, positive vascular margins are associated with risk for disease progression. However, the risk of relapse associated with positive vascular margin is driven by 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.