Impact of positive vascular margins status after surgical resection of non-metastatic renal cell carcinoma with caval tumour thrombus: a propensity score multicentre study.

Background: Data evaluating the impact of positive vascular margins (PVMs) following surgical resection of non-metastatic renal cell carcinoma (RCC) with inferior vena cava (IVC) tumor thrombus are lacking.

Objective: To analyze the oncological impact of positive vascular margins following surgical resection of RCC with IVC tumor thrombus.

Methods: Patients who underwent radical nephrectomy with the removal of IVC tumour thrombus for RCC between 2000 and 2019 were included. PVMs were identified from pathology reports defined as microscopically identified tumour present in the IVC wall at the site of resection or in case of thrombus was not completely removed. To achieve balance in baseline characteristics between patients with PVMs versus negative vascular margins, we used inverse probability of treatment weighting (IPTW) based on the propensity score. Local recurrence, distant metastasis and overall mortality were evaluated between groups using Cox proportional hazards regression models.

Results: 209 patients were analyzed. Among them, 49 (23%) patients with PVMs were identified. Median follow-up was 55 months. After adjustment, excellent balance was achieved for most propensity score variables. In IPTW analysis, PVMs was associated with a higher risk of local recurrence (HR = 3.66; p < 0.001) without any impact on systemic recurrence (HR = 1.15; p = 0.47) or overall mortality (HR = 1.23; p = 0.48). Limitations include the sample size and unmeasured confounding.

Conclusion: Our results suggest that a PVMs in patients with RCC after nephrectomy with thrombectomy is associated with a higher risk of local recurrence, however, it did not appear to influence the risk of distant metastasis or death.