Lifestyle and Anthropometric Risk Factors for Prostate Cancer in a Cohort of Iowa Men

PURPOSE: Several lines of evidence suggest that prostate cancer has a hormonal etiology. We evaluated factors known to modulate the endocrine system, including alcohol and tobacco use, physical activity, and obesity as risk factors for prostate cancer. METHODS: Cancer-free controls n = 1572 who participated in a population-based case-control study from 1986–1989 (81% response rate) were followed through 1995 for cancer incidence by linkage to the Iowa Cancer Registry; 101 incident prostate cancers were identified. RESULTS: Compared with non-users of alcohol, men who consumed 96 grams alcohol per week (RR = 3.1; 95% CI 1.5–6.3) were at increased risk of prostate cancer after adjustment for age, family history of prostate cancer, body mass index, total energy, and intake of carbohydrate, linoleic acid, lycopene, retinol, and red meat ( p for trend < 0.0001). The respective RRs were similar when assessing type of alcohol consumed (beer, wine or liquor) or when well-differentiated, localized tumors were excluded. Body mass index was only weakly and positively associated with prostate cancer after adjustment for age p for trend = 0.3 , but this association strengthened after multivariate adjustment p for trend = 0.08 and exclusion of well-differentiated, localized tumors p for trend = 0.03 . For the latter tumors, men with a BMI of 24.1–26.6 kg/ m 2 RR = 1.5; 95% CI 0.7 – 3.0 and >26.6 kg/ m 2 RR = 2.1; 95% CI 1.1–4.3 were at elevated risk compared to men with a BMI