The authors note that obesity is associated with a number of chronic diseases such as coronary artery disease, hypertension and diabetes as well as CaP mortality, but it is not clearly associated with CaP incidence. This is a case-control study nested within the PSA-testing phase of the Prostate testing for cancer and Treatment (ProtecT) study. It evaluates associations of obesity with screening-detected CaP. Obesity was measured by body mass index (BMI), waist circumference and waist-to-hip ratio (WHR).
Patients included in the analysis were age 50-69 years who had PSA testing and a diagnosis of CaP. They were matched for clinicopathologic characteristics with controls. Assessed metrics were both objective and patient-reported. Data was complete for BMI, age and family history for 3,931 controls and 919 cases.
More cases (8.1%) than controls (5.2%) had a family history of CaP. Regarding obesity, in the highest tertiles there were 18.4% cases and 21.5% controls with a BMI ≥30kg m-2. There were 30.5% of cases with >99cm waist circumference compared with 32.1% for controls. WHR was >0.95 in 31.8% of cases and 33.9% of controls. After exclusions for missing data, the number of cases (1,089) and controls (5,020) used in the analysis was similar to the eligible participants not included in the analysis in terms of family history of CaP. However, in terms of age, those included were on average one year older than those not included. Considering BMI, waist measurement and WHR, there was no relationship between any of these three obesity measures and total prostate cancer. Only BMI had a minimally significant relationship to pathological stage or grade.
Dimitropoulou P, Martin RM, Turner EL, Lane JA, Gilbert R, Davis M, Donovan JL, Hamdy FC, Neal DE