Prospective study of adiposity and weight change in relation to prostate cancer incidence and mortality.
BACKGROUND
Adiposity has been linked inconsistently with prostate cancer, and few studies have evaluated whether such associations vary by disease aggressiveness.


METHODS
The authors prospectively examined body mass index (BMI) and adult weight change in relation to prostate cancer incidence and mortality in 287,760 men ages 50 years to 71 years at enrollment (1995-1996) in the National Institutes of Health-AARP Diet and Health Study. At baseline, participants completed questionnaires regarding height, weight, and cancer screening practices, including digital rectal examinations and prostate-specific antigen tests. Cox regression analysis was used to calculate relative risks (RR) and 95% confidence intervals (95% CIs).


RESULTS
In total, 9986 incident prostate cancers were identified during 5 years of follow-up, and 173 prostate cancer deaths were ascertained during 6 years of follow-up. In multivariate models, higher baseline BMI was associated with significantly reduced total prostate cancer incidence, largely because of the relationship with localized tumors (for men in the highest BMI category [>or=40 kg/m(2)] vs men in the lowest BMI category [<25 kg/m(2)]: RR, 0.67; 95% CI, 0.50-0.89; P = .0006). Conversely, a significant elevation in prostate cancer mortality was observed at higher BMI levels (BMI <25 kg/m(2): RR, 1.0 [referent group]; BMI 25-29.9 kg/m(2): RR, 1.25; 95% CI, 0.87-1.80; BMI 30-34.9 kg/m(2): RR, 1.46; 95% CI, 0.92-2.33; and BMI >or=35 kg/m(2): RR, 2.12; 95% CI, 1.08-4.15; P = .02). Adult weight gain from age 18 years to baseline also was associated positively with fatal prostate cancer (P = .009), but not with incident disease.


CONCLUSIONS
Although adiposity was not related positively to prostate cancer incidence, higher BMI and adult weight gain increased the risk of dying from prostate cancer.
Wright
Margaret E
ME
Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland, USA. mewright@uic.edu
Chang
Shih-Chen
SC
Schatzkin
Arthur
A
Albanes
Demetrius
D
Kipnis
Victor
V
Mouw
Traci
T
Hurwitz
Paul
P
Hollenbeck
Albert
A
Leitzmann
Michael F
MF
D050154:Adiposity; D000368:Aged; D050218:Body Fat Distribution; D015992:Body Mass Index; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009765:Obesity; D011446:Prospective Studies; D011471:Prostatic Neoplasms / Q000209:etiology / Q000401:mortality*; D012307:Risk Factors; D011795:Surveys and Questionnaires; D015996:Survival Rate; D049629:Waist-Hip Ratio; D015430:Weight Gain