Affiliation:
1. 1Department of Population Science, American Cancer Society, Kennesaw, Georgia.
2. 2Departments of Medicine and Oncology, McGill University, Montreal, Quebec, Canada.
3. 3Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, New York.
Abstract
Abstract
Background:
Few prospective studies have examined biomarkers of glucose homeostasis or inflammation with prostate cancer risk by tumor stage or grade.
Methods:
We conducted a case–cohort study to examine associations of prediagnosis hemoglobin A1c (HbA1c), C-peptide, and C-reactive protein (CRP) with prostate cancer risk overall and stratified by tumor stage and grade. The study included 390 nonaggressive (T1–2, N0, M0, and Gleason score <8) and 313 aggressive cases (T3–4, or N1, or M1, or Gleason score 8–10) diagnosed after blood draw (1998–2001) and up to 2013, and a random subcohort of 1,303 cancer-free men at blood draw in the Cancer Prevention Study-II Nutrition Cohort. Prentice-weighted Cox proportional hazards regression models were used to estimate HRs and 95% confidence intervals (CI).
Results:
In the multivariable-adjusted model without body mass index, HbA1c was inversely associated with nonaggressive prostate cancer (HR per unit increase, 0.89; 95% CI, 0.80–1.00; P = 0.04). Analyses stratified by tumor stage and grade separately showed that HbA1c was inversely associated with low-grade prostate cancer (HR per unit increase, 0.89; 95% CI, 0.80–1.00) and positively associated with high-grade prostate cancer (HR per unit increase, 1.15; 95% CI, 1.01–1.30). C-peptide and CRP were not associated with prostate cancer overall or by stage or grade.
Conclusions:
The current study suggests that associations of hyperglycemia with prostate cancer may differ by tumor grade and stage.
Impact:
Future studies need to examine prostate cancer by tumor stage and grade, and to better understand the role of hyperglycemia in prostate cancer progression.
Publisher
American Association for Cancer Research (AACR)