Introduction:

Previous studies have established African Americans with renal cell carcinoma (RCC) have aggressive tumors and worse outcomes compared to other races.  The impact of racial differences on locally advanced tumors (specifically tumor thrombus) and metastatic RCC (mRCC) remains unclear.  We aim to evaluate survival outcomes among different racial groups in a population of RCC tumor thrombus patients.

Methods:

This retrospective study, approved by the IRB with a consent waiver, analyzed patients aged 40-80 with primary (RCC) and tumor thrombus who underwent nephrectomy between 2010 and 2015 using the National Cancer Database (NCDB). The study focused on patients with RCC and tumor thrombus to assess survival differences between racial backgrounds.  Demographic covariates included age, sex, and race and ethnicity (non-Hispanic White, non-Hispanic African American, Hispanic, or none of the above). Clinical covariates included stage, grade, subtype, tumor thrombus level, type of surgery, comorbidities, hospital type, and patient residence.  

The data were analyzed with statistical tests including Kruskal-Wallis, Chi-square, and log-rank tests to compare results by race/ethnicity. Survival outcomes were assessed with Kaplan-Meier curves, and multivariable analyses employed Cox proportional hazards regression and multinomial logistic regression. All analyses were conducted using Stata/SE 18.0, with significance set at P<0.05.

Results:

We identified 11,520 patients, aged 40-80, with the diagnosis of renal cell carcinoma (RCC) and tumor thrombus who underwent surgery from 2010-2015. Among them, 83% were non-Hispanic White, 6% non-Hispanic African American, 7% Hispanic, and 3% other races.

Mortality rates were 55% overall and 82% in metastatic RCC (mRCC) cases.  The study population included 2,429 mRCC patients.  Survival analysis showed African Americans had lower survival compared to Caucasians in both the overall and mRCC cohorts. Multivariable analysis confirmed higher mortality for African Americans ( HR: 1.22 overall with P<0.001; 1.24 in mRCC with p=0.019).

Overall, 5-year survival rates according to the presence of tumor thrombus did not differ among higher levels between Caucasians and African Americans for level I-III 39% and 46%, p=0.21; and Level IV 39% and 39%, p=0.39, respectively.  There was a survival advantage for Level 0 tumor thrombus among the Caucasian population, p<0.001 Log-rank test.

Conclusion:

African American patients diagnosed with RCC and tumor thrombus face a 22% higher risk hazard of mortality compared to non-Hispanic white patients. They often present with more locally advanced and mRCC.  The mortality risk hazard for metastatic RCC is increased by 24% compared to Caucasians. The results underscore the demographic impact of race on disease severity and support clinical consideration when managing African American patients.

Funding: N/A