Understanding racial disparities in renal cell carcinoma incidence: estimates of population attributable risk in two US populations

• Published in: Cancer causes & control Vol. 31; no. 1; pp. 85 - 93
• Main Authors: Callahan, Catherine L., Schwartz, Kendra, Corley, Douglas A., Ruterbusch, Julie J., Zhao, Wei K., Shuch, Brian, Graubard, Barry I., Rothman, Nathaniel, Chow, Wong-Ho, Silverman, Debra T., Purdue, Mark P., Hofmann, Jonathan N.
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.01.2020; Springer Nature B.V
• Subjects: Adult; African Americans; Aged; Biomedical and Life Sciences; Biomedicine; Black or African American; California - epidemiology; Cancer Research; Carcinoma, Renal Cell - complications; Carcinoma, Renal Cell - epidemiology; Carcinoma, Renal Cell - ethnology; Case-Control Studies; Chicago - epidemiology; Cigarette smoking; Comorbidity; Electronic Health Records; Epidemiology; Female; Health Status Disparities; Healthcare Disparities; Hematology; Humans; Hypertension; Hypertension - complications; Hypertension - epidemiology; Hypertension - ethnology; Incidence; Kidney cancer; Kidney diseases; Kidney Neoplasms - complications; Kidney Neoplasms - epidemiology; Kidney Neoplasms - ethnology; Male; Michigan - epidemiology; Middle Aged; Obesity; Oncology; Original Paper; Prevalence; Public Health; Race; Renal cell carcinoma; Risk Factors; Smoking; White People; Women; Young Adult; Chicago; California; Michigan; United States > US; Hypertension; African Americans; Chronic kidney disease; Population attributable risk; Kidney cancer
• ISSN: 0957-5243; 1573-7225; 1573-7225
• DOI: 10.1007/s10552-019-01248-1

Purpose Renal cell carcinoma (RCC) incidence is higher among black than white Americans. The reasons for this disparity remain unclear. Methods We calculated race- and sex-specific population attributable risk percentages (PAR%) and their 95% confidence intervals (CI) for hypertension and chronic kidney disease (CKD) among black and white subjects ≥  50 years of age from the US Kidney Cancer Study (USKC; 965 cases, 953 controls), a case–control study in Chicago and Detroit, and a nested case–control study in the Kaiser Permanente Northern California health care network (KPNC; 2,162 cases, 21,484 controls). We also estimated PAR% for other modifiable RCC risk factors (cigarette smoking, obesity) in USKC. Results In USKC, the PAR% for hypertension was 50% (95% CI 24–77%) and 44% (95% CI 25–64%) among black women and men, respectively, and 29% (95% CI 13–44%) and 27% (95% CI 14–39%) for white women and men, respectively. In KPNC, the hypertension PAR% was 40% (95% CI 18–62%) and 23% (95% CI 2–44%) among black women and men, and 27% (95% CI 20–35%) and 19% (95% CI 14–24%) among white women and men, respectively. The PAR% for CKD in both studies ranged from 7 to 10% for black women and men but was negligible (<1%) for white subjects. In USKC, the PAR% for current smoking was 20% and 8% among black and white men, respectively, and negligible and 8.6% for black and white women, respectively. The obesity PAR% ranged from 12 to 24% across all race/sex strata. Conclusions If the associations found are causal, interventions that prevent hypertension and CKD among black Americans could potentially eliminate the racial disparity in RCC incidence (hypothetical black:white RCC incidence ratio of 0.5).