Abstract 12P
Background
Renal cell carcinoma represents 2% of all adult tumors. Histologically, the most common subtype is Clear cell while papillary and chromophobe subtypes are very rare. Metastasis is a poor prognostic factor for renal cell carcinoma and racial disparities betweens African-Americans (AA) and Caucasians (C) in metastasis patterns require further investigation. So this study aims to compare the patterns of metastasis between African-Americans and Caucasians among different histological subtypes of renal cell carcinoma.
Methods
Data were extracted from Surveillance, Epidemiology, and End Results Program (SEER) database from 2010-2019. We extracted data of patients with clear cell, papillary, and chromophobe renal cell carcinoma who presented with metastasis to bone, brain, liver, or lung at the time of diagnosis. We calculated the relative risk (RR) and confidence interval (CI) using SPSS software, version 25.0 (IBM).
Results
Clear cell carcinoma was the most prevalent subtype of renal cell carcinoma. Compared to African-Americans, Caucasians had lower risk of liver metastasis in clear cell subtype (RR=0.76, 95% CI: 0.61-0.94, P=0.11) while Caucasians who had clear cell subtype showed higher risk of lung metastasis (RR=1.22, 95% CI: 1.08-1.39, P>0.001). Papillary subtype tend to metastasize more to the lungs with no statistical significance between Caucasians and African-Americans (1.8% and 2.1% respectively, RR 1.13, CI: 0.87-1.45, P=0.34). Table: 12P
| Cancer | Total number of patients by race | AA compared to C. Metastasis site prevalence (%). Relative risk, 95% confidence interval, and p-value |
| Clear cell RCC | AA: 4959C: 63033 | Bone: AA 179 (3.6%) C 2336 (3.7%) – RR 1.02 – CI [0.88 to 1.19] P=0.72Liver: AA 95 (1.9%) C 922 (1.5%) – RR 0.76 – CI [0.61 to 0.94] P=0.011Lung: AA 247 (5.0%) C 3849 (6.1%) – RR 1.22 – CI [1.08 to 1.39] P<0.001 |
| Papillary RCC | AA: 4454C: 10705 | Liver: AA 48 (1.1%) C 77 (0.7%) – RR 0.66 – CI [0.46 to 0.95] P=0.26Lung: AA 81 (1.8%) C 220 (2.1%) – RR 1.13 – CI [0.87 to 1.45] P=0.34 |
| Chromophobe RCC | AA: 861C: 5560 | Liver: AA 6 (0.7%) C 28 (0.5%) – RR 0.72 – CI [0.30 to 1.74] P=0.46Lung: AA 2 (0.2%) C 44 (0.8%) – RR 3.40 – CI [0.82 to 14.0] P=0.70 |
Conclusions
Across multiple subtypes of renal cancer, clear cell carcinoma showed significant differences regarding liver and lung metastasis between Caucasians and African-Americans regarding the risk of metastasis. Further studies of genetic and biological factors are warranted.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.