Abstract PR16: Association of renal cell carcinoma subtypes with race/ethnicity and comorbid medical conditions
Authors: Lichtensztajn Daphne Y. , Hofer Brenda M. , Leppert John T. , Brooks James D. , Chung Benjamin I. , Shah Sumit A. , DeRouen Mindy C. , Gomez Scarlett L. , Cheng Iona 
Published: September 2020

Abstract
Background: Renal cell carcinomas (RCC) comprise distinct subtypes that differ in molecular characteristics and prognosis. The distribution of these subtypes varies by race/ethnicity. Hypertension, obesity, chronic kidney disease, and diabetes have been associated with increased risk of RCC, and emerging evidence suggests that the risk may be subtype specific. We assessed whether race/ethnicity and comorbidities were independently associated with RCC subtypes.
Methods: Using population-based data from the California Cancer Registry linked to the Office of Statewide Health Planning and Development, we identified non-Latino White, non-Latino Black, Latino, and Asian/ Pacific Islander adults diagnosed with their first microscopically confirmed RCC between 2005 and 2015. Diagnosis of hypertension, diabetes, and kidney disease was defined by ICD-9 and ICD-10 codes present prior to RCC diagnosis. We used multivariable logistic regression to model the association of the three main RCC subtypes (clear cell, papillary, and chromophobe) with race/ethnicity adjusting for comorbidity, sex, neighborhood socioeconomic status, age, and year of diagnosis.
Results: Of the 40,016 cases of RCC included, 62.6% were clear cell, 10.9% papillary, and 6.0% chromophobe. There were striking differences in the proportion of clear cell and papillary subtypes by race/ethnicity, ranging from 40.4% clear cell and 30.4% papillary in non-Latino Black adults to 70.7% clear cell and 4.5% papillary in Latino adults. The prevalence of comorbid conditions also varied by race/ethnicity—most notably the greater prevalence of kidney disease in the non-Latino Black group. In multivariable analysis, non-Latino Black individuals had a higher likelihood of presenting with papillary (odds ratio (OR) 3.35, 95% confidence interval (CI) 3.05-3.68) and chromophobe (OR 1.23, 95% CI 1.06-1.44) subtype compared to those identified as non-Latino White. In contrast, both Latino and Asian/Pacific Islander individuals were more likely than those of non-Latino White race/ethnicity to present with clear-cell subtype (OR 1.48, 95% CI 1.41-1.56 and OR 1.30, 95% CI 1.20-1.40, respectively). Clear-cell subtype was associated with diabetic renal disease (OR 1.39, 95%CI 1.23-1.58) and uncomplicated diabetes (OR 1.29, 95% CI 1.22-1.37), while papillary subtype was associated with hypertension (OR 1.22, 95% CI 1.13-1.32), hypertensive renal disease (OR 1.53, 95% CI 1.34-1.75), and end-stage renal disease (OR 1.55, 95% CI 1.31-1.84).
Conclusion: In addition to race/ethnicity, specific comorbidities are associated with RCC subtype. The association of diabetes, hypertension, and end-stage renal disease with RCC subtype may provide clues to disease etiology as well as avenues for disease prevention.
This abstract is also being presented as Poster D119.
Citation Format: Daphne Y. Lichtensztajn, Brenda M. Hofer, John T. Leppert, James D. Brooks, Benjamin I. Chung, Sumit A. Shah, Mindy C. DeRouen, Scarlett L. Gomez, Iona Cheng. Association of renal cell carcinoma subtypes with race/ethnicity and comorbid medical conditions [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr PR16.