If you want to reduce your risk of prostate cancer, better drop a few pants sizes. A study of almost 150,000 men from 8 European countries, presented at this year's European Obesity Summit shows that higher body mass index (BMI) and waist circumference are associated with an increased risk of aggressive prostate cancer.

This analysis of the European Prospective Investigation into Cancer and Nutrition (EPIC) is by Dr Aurora Perez-Cornago, Cancer Epidemiology Unit, Nuffield Department of Population Health, University of Oxford, UK, and colleagues.

To date, evidence on the association of body size and adiposity with prostate cancer risk is not clear. In this study, the authors investigated the associations between various body measurements at baseline, mainly BMI and waist circumference, and the risk of prostate cancer incidence, with a focus on tumor stage and grade, and on mortality from prostate cancer. A total of 141,896 men with a mean age at recruitment of 52 years in 8 European countries (Italy, Spain, United Kingdom, the Netherlands, Greece, Germany, Sweden, and Denmark) from the EPIC cohort were included. Data were adjusted for education level, smoking, marital status, diabetes and physical activity.

After an average of 14 years of follow-up there were 7,022 incident cases of prostate cancer, of which 934 were fatal. The researchers focused on aggressive prostate cancer, looking at cancers with a high grade and cancers which resulted in death.

Men with a higher BMI and waist circumference had an increased risk of high grade prostate cancer, an aggressive form of the disease (10 percent increased risk for BMI for every 5 kg/m2 increase and 13 percent for waist circumference for every 10cm increase).

Furthermore, a 14 percent higher risk for fatal prostate cancer was observed for every 5 kg/m2 increase in BMI, and 18 percent increased risk in every 10 cm increase in waist circumference.

The authors conclude: "The findings from this large prospective study show that the association between body size and prostate cancer is complex and varies by disease aggressiveness; men who have greater adiposity have an elevated risk of high grade prostate cancer and prostate cancer death."

They add: "Our results are in line with health advice for other non-communicable diseases. Men should try to maintain a healthy weight."