Body size across the life course and prostate cancer in the Health Professionals Follow-up Study.

Current evidence of an association between body size and prostate cancer is conflicting, possibly due to differential effects of body size across the lifespan and the heterogeneity of the disease. We therefore examined childhood and adult body size in relation to total incident prostate cancer and prognostic subtypes in a prospective cohort of 47,491 US men in the Health Professionals Follow-up Study. We assessed adult height, body mass index (BMI) in early and middle-to-late adulthood, adult waist circumference, and body shape at age 10. With follow-up from 1986 to 2010, we estimated the relative risk (RR) of prostate cancer using Cox proportional hazards models. We identified 6,183 incident cases. Tallness was associated with increased risk of advanced-stage tumors, particularly fatal disease (RR = 1.66, 95% CI 1.23-2.23, highest vs. lowest quintile, ptrend < 0.001). High BMI at age 21 was inversely associated with total prostate cancer (RR = 0.89, 95% CI 0.80-0.98, BMI ≥ 26 vs. 20-21.9, ptrend = 0.01) and with fatal and advanced disease. The association for late adult BMI differed by age (pinteraction < 0.001); high BMI was inversely associated with total prostate cancer (RR = 0.64, 95% CI 0.51-0.78, BMI ≥ 30 vs. 21-22.9, ptrend <0.001) and with non-advanced and less aggressive tumors among men ≤ 65 years, whereas no association was seen among men >65 years. Adult waist circumference was weakly inversely associated with less aggressive disease. Childhood obesity was unclearly related to risk. Our study confirms tall men to be at increased risk of fatal and advanced prostate cancer. The influence of adiposity varies by prognostic disease subtype and by age. The relationship between body size and prostate cancer is complex. Body size changes progressively throughout life and consequent effects on prostate cancer risk may be associated with related changes in hormonal and metabolic pathways. This large prospective study examined potential associations between the risk of various prostate cancer subtypes and multiple anthropometric measures at different ages in men. Tallness was confirmed to be associated with an elevated risk of advanced prostate cancer, particularly fatal disease. The extent to which body weight influenced risk varied according to factors such as age and disease subtype.