Positive vascular wall margins have minimal impact on cancer outcomes in patients with non-metastatic renal cell carcinoma (RCC) with tumour thrombus

Objective To evaluate the impact of microscopically positive vascular margins on recurrence and cancer-specific survival (CSS) in patients with renal cell carcinoma (RCC) with venous thrombus Patients and Methods We reviewed the records from the period 1993 to 2009 of consecutive patients treated surgically for RCC with venous tumour thrombus at the University of Texas MD Anderson Cancer Center. Patients with metastatic disease, positive soft tissue margins or gross residual disease at time of thrombectomy were excluded. The primary outcome measures were local or systemic disease recurrence, and CSS. Univariate and multivariate analysis were used to evaluate whether microscopically positive vascular margins were associated with RCC recurrence or CSS after nephrectomy with thrombectomy. Results A total of 256 patients with RCC were identified with a median (interquartile range) follow-up of 36.7 (18.4-63.5) months. Microscopic tumour was present at the margin of resection in 47 patients (18.4%). The median recurrence-free interval was significantly shorter in patients with positive vascular margins: 22.1 vs 70.2 months (P = 0.009). The rate of local recurrence was higher in patients with positive vein margins: 12.8 vs 4.3% (P < 0.01). Local recurrence without concomitant systemic recurrence was identified in only two of 256 (0.8%) patients. Patients with positive vascular margins had significantly worse CSS times compared with patients with negative vascular margins: 37.7 vs 93.0 months (P = 0.004). In multivariable analysis, positive vascular margins were found to be independently predictive of local recurrence but not of systemic recurrence or CSS. Conclusions Complete surgical excision should always be attempted because positive vascular wall margins increase local recurrence rates. Invasion of RCC into the vein wall at the resection margin is associated with aggressive tumour biology, and the majority of patients with positive vascular wall margins experience systemic recurrence.