Men should try to maintain a healthy weight as researchers have found that higher body mass index (BMI) and waist circumference are associated with an increased risk of aggressive prostate cancer.

In this study, the researchers 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 tumour 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 eight European countries (Italy, Spain, Britain, the Netherlands, Greece, Germany, Sweden and Denmark) were included.

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 focussed on aggressive prostate cancer, looking at cancers with a high grade and cancers which resulted in death (fatal prostate cancer).

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

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

"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," the researchers noted.

The study by Aurora Perez-Cornago from University of Oxford, and colleagues was presented at the European Obesity Summit in Gothenburg, Sweden.