Evaluating the relationship between vasculitis and metastasis in kidney-related urogenital cancers: A multicenter real-world propensity-matched cohort study.

Abstract

561 Background: Vasculitis, a disorder with systemic inflammation and immune dysregulation, can create a pro-tumorigenic microenvironment. While its connection with higher cancer incidence is recognized, its specific role in cancer development and metastatic spread remains poorly characterized. This study aims to evaluate whether a pre-existing diagnosis of vasculitis is associated with an increased risk of metastasis in patients with urogenital cancer. Methods: Using the multinational TriNetX database, we conducted a propensity-matched cohort study. Patients with malignant kidney, upper tract, or bladder cancer and a diagnosis of vasculitis were compared to a matched cohort with the same cancers but without vasculitis. A 3-year lookback period was used for comorbidity assessment. The primary outcome was the development of metastasis following the initial cancer diagnosis. By restricting the cohort to non-metastatic cancers at baseline, metastasis was assessed as a subsequent outcome rather than a pre-existing condition. The secondary outcome was all-cause mortality, analyzed using Kaplan-Meier estimates and Cox proportional hazards models. Results: After matching, 2,222 patients were distributed to both groups. Patients with vasculitis had a significantly higher risk of metastasis than those without vasculitis (Hazard Ratio [HR] 1.68, 95% CI 1.26-2.24, p = 0.032). Survival without metastasis was 81.7% in the vasculitis group compared to 93.9% in the control group. Conversely, the difference in all-cause mortality was not statistically significant (HR 1.04, 95% CI 0.93-1.17, p = 0.050), though survival probabilities at 5 years were much lower in the vasculitis group (27.1% compared to 41.9%). Conclusions: Vasculitis is associated with a significantly higher risk of metastasis in urogenital cancer patients. These findings position vasculitis as a potential marker for aggressive disease. Increased vigilance and targeted management may be warranted for those urogenital cancer patients with accompanying vasculitis to combat this increased risk of metastasis.