Association of renal artery variations with aggressive pathological features and poor prognosis in clear-cell renal cell carcinoma: a computed tomography-based three-dimensional reconstruction study.

BACKGROUND: Clear-cell renal cell carcinoma (ccRCC), the most common subtype of kidney cancer, is characterized by its hypervascular nature. Its dependence on neo-angiogenesis is well-documented; however, the relationship between congenital vascular architecture and tumor biology remains obscure. This study aimed to investigate the association between pre-existing renal artery variation and ccRCC aggressiveness and patient prognosis.

METHODS: This retrospective study included the clinicopathological and imaging data of 386 patients with ccRCC. Preoperative computed tomography images underwent three-dimensional (3D) reconstruction to evaluate renal artery variations. Using a self-controlled design, a total of 772 renal units were analyzed. Appropriate parametric and non-parametric tests were performed to compare renal artery variations between tumor-affected kidneys and contralateral healthy kidneys, and to further evaluate the association between renal artery variations and clinicopathological characteristics. Further, a Kaplan-Meier survival analysis and multivariate Cox proportional hazards regression models were employed to evaluate the impact of renal artery variations on survival outcomes, including progression-free survival (PFS) and overall survival (OS), and to identify independent prognostic factors.

RESULTS: The incidence of renal artery variations was significantly higher in the ccRCC-affected kidneys (66.3%) than in the contralateral healthy kidneys (P<0.001). Among the variations, accessory renal artery (ARA) was the most common type (45.3%), with both its number (P<0.001) and origin (P<0.001) exhibiting greater complexity. ARA was significantly associated with several aggressive clinicopathological features, including exophytic growth (P=0.015), a larger tumor diameter (P<0.001), an increased tumor volume (P<0.001), pathological necrosis (P<0.001), and a higher World Health Organization/International Society of Urological Pathology (WHO/ISUP) grade (P=0.028). In addition, tumor-feeding ARAs were associated with higher rates of intratumoral hemorrhage (P=0.038) and cystic degeneration (P=0.025). The Kaplan-Meier analysis revealed that the presence of ARAs was significantly associated with shorter OS (P<0.001) and PFS (P<0.001). The multivariate Cox regression analysis further identified the presence of ARAs as an independent prognostic factor for PFS (hazard ratio =8.33, P=0.047).

CONCLUSIONS: Renal artery variations are common in patients with ccRCC. Specifically, the presence of ARAs is closely associated with aggressive tumor growth patterns, pathological characteristics, and a poorer prognosis. These findings suggest that ARAs may play a crucial role in tumor development and progression.