Racial disparities in renal cell carcinoma histology and outcomes: Insights from the French Kidney Cancer Research Network (UroCCR-191).

Abstract

442 Background: In the U.S., racial disparities in renal cell carcinoma (RCC) are documented for common histologies, highlighting differences in incidence and outcomes between Black and non-Black patients. Such disparities are underexplored in European populations, especially across a broader histology spectrum within a universal healthcare system. We aim to investigate racial disparities in RCC histologies and their outcomes among Black and non-Black patients in France. Methods: We conducted a retrospective cohort study utilizing the UroCCR database, spanning from March 1957 to May 2024. This multicenter study, referred as UroCCR-191, involved 30 tertiary centers in France, analyzing 9,404 patients (338 Black and 9,066 non-Black) with confirmed histology. Patients with unknown racial background or unidentified/multiple histologies were excluded. Histological distribution, demographics, clinical presentations, tumor features, and outcomes were compared. Results: Clear cell RCC (ccRCC) was more prevalent among non-Black patients (68.8% vs 47.6%; odds ratio [OR]: 2.4, p < 0.001). Non-clear cell histologies were more common in Black patients, including papillary RCC (23.1% vs 11.8%, p < 0.001), the rare clear cell papillary renal cell tumor (1.5% vs 0.5%, p = 0.044), and other rare molecularly-defined histologies such as translocation RCC (2.1% vs 0.6%, p = 0.005), FH-deficient RCC (0.6% vs 0.1%, p = 0.067) and renal medullary carcinoma (0.3% vs 0, p = 0.001); all with OR ≥2 and a false discovery rate <0.15. Black patients were younger at diagnosis, with earlier-stage tumors and higher rates of partial nephrectomy. No significant differences were observed in cancer-specific survival; however, Black patients showed better distant recurrence-free survival (hazard ratio [HR]: 0.55, p = 0.020). Race was not an independent prognostic factor when accounting for other clinical variables (Table). Conclusions: Black patients in France exhibit higher incidences of non-clear cell RCC and are diagnosed at earlier stages compared to non-Black patients. The absence of race as an independent prognostic factor, unlike U.S. data, highlights the potential influence of healthcare systems in modulating racial disparities. This underscores the need for tailored RCC management that considers racial backgrounds to refine diagnosis and outcomes. Hazard ratios using multivariate Cox regression for predictors of distant recurrence-free survival. Variable Reference group Comparison group HR 95% CI p -value Race non-Black Black 0.96 0.51-1.79 0.889 Age (years) ≤63 >63 1.25 1.07-1.47 0.005 Sex Female Male 1.29 1.09-1.53 0.004 Nephrectomy type Partial Radical 2.98 2.46-3.61 <0.001 T stage T1 + T2 T3 + T4 2.36 1.96-2.85 <0.001 N stage N0 N1 + N2 2.84 2.25-3.58 <0.001 Fuhrman grade 1 + 2 3 + 4 2.39 1.97-2.91 <0.001 Histology ccRCC non-ccRCC 0.81 0.65-1.01 0.062