Oxidative Balance Score and Risk for Incident Prostate Cancer in a Prospective U.S. Cohort Study
Menée aux Etats-Unis auprès de 43 325 participants, cette étude de cohorte prospective évalue l'association entre des indicateurs de l'équilibre oxydant-antioxydant et le risque de cancer de la prostate
Oxidative stress is defined as an imbalance between pro-oxidants and anti-oxidants. Previous research found that a single comprehensive oxidative balance score (OBS) that includes individual pro- and anti-oxidant exposures may be associated with various conditions (including prostate cancer) in the absence of associations with the individual factors. We investigated an OBS-incident prostate cancer association among 43,325 men in the Cancer Prevention Study-II Nutrition Cohort. From 1999 to 2007, 3,386 incident cases were identified. Twenty different components, used in two ways (unweighted or weighted based on literature reviews), were incorporated into the OBS and the resulting scores were then expressed as three types of variables (continuous, quartiles, or six equal intervals). Multivariable-adjusted rate ratios were calculated using Cox proportional hazards models. We hypothesized that the OBS would be inversely associated with prostate cancer risk; however, the rate ratios (95% confidence intervals) comparing the highest to the lowest OBS categories ranged from 1.17 (1.04-1.32) to 1.39 (0.90-2.15) for all cases, 1.14 (0.87-1.50) to 1.59 (0.57-4.40) for aggressive disease (AJCC stage III/IV or Gleason score 8-10), and 0.91 (0.62-1.35) to 1.02 (1.02-1.04) for non-aggressive disease. Our findings are not consistent with the hypothesis that oxidative balance-related exposures collectively affect risk for prostate cancer