The association of diabetes and obesity with prostate cancer aggressiveness among Black Americans and White Americans in a population-based study

Few studies have investigated the role of race in the association of diabetes and obesity with prostate cancer aggressiveness. Here we evaluate the independent association between diabetes and obesity with prostate cancer aggressiveness in White Americans and Black Americans.

Our cross-sectional, case-only study consisted of 1,058 White Americans and 991 Black Americans from the North Carolina-Louisiana Prostate Cancer (PCaP) project. Diabetes status was determined by self-report. Obesity was determined using body mass index and calculated based on anthropometric measurements. High aggressive prostate cancer was defined as Gleason sum ≥8, or prostate-specific antigen >20 ng/ml, or Gleason sum = 7 and clinical stage cT3-cT4. The association between diabetes and obesity with high aggressive prostate cancer at diagnosis was evaluated using multivariable logistic regression and adjusted for potential confounders.

Diabetes was not associated with high aggressive prostate cancer in the overall sample (OR 1.04; 95% CI 0.79, 1.37), White Americans (OR 1.00; 95% CI 0.65, 1.57) or Black Americans (OR 1.07; 95% CI 0.75, 1.53). Obesity, independent of diabetes, was positively associated with high aggressive prostate cancer in White Americans (OR 1.98; 95% CI 1.14, 3.43), but not in the overall sample (OR 1.37; 95% CI 0.99, 1.92) or Black Americans (OR 1.09; 95% CI 0.71, 1.67).

Diabetes was not associated with prostate cancer aggressiveness, overall, or in either race group. Obesity, independent of diabetes, was associated with high aggressive prostate cancer only in White Americans.

Cancer causes & control : CCC. 2016 Nov 09 [Epub ahead of print]

Saira Khan, Jianwen Cai, Matthew E Nielsen, Melissa A Troester, James L Mohler, Elizabeth T H Fontham, Laura H Hendrix, Laura Farnan, Andrew F Olshan, Jeannette T Bensen

Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina-Chapel Hill, 135 Dauer Drive, Chapel Hill, NC, 27599, USA. ., Department of Biostatistics, Gillings School of Global Public Health, University of North Carolina-Chapel Hill, 135 Dauer Drive, Chapel Hill, NC, 27599, USA., Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina-Chapel Hill, 135 Dauer Drive, Chapel Hill, NC, 27599, USA., Department of Urology, School of Medicine, University of North Carolina-Chapel Hill, 170 Manning Dr., Chapel Hill, NC, 27599, USA., School of Public Health, Louisiana State University Health Science Center, 2020 Gravier Street, New Orleans, LA, 70112, USA., Lineberger Comprehensive Cancer Center, School of Medicine, University of North Carolina-Chapel Hill, 450 West Drive, Chapel Hill, NC, 27599, USA.