Prostate cancer 'riskier for tall and obese men'
13th July 2017 – Tall men and those who are obese have a higher risk of high grade prostate cancer and dying from the disease, a study has found.
A research team led by the University of Oxford found that while being tall did not increase the overall risk of getting prostate cancer, it did increase the risk of high grade tumours that spread more quickly.
Height, BMI and waist size
They say that the risk of high grade cancer increases by 21% with each additional 10cm (3.9 inches) of height. Also, each 10cm increment increases the risk of dying by 17%.
Men with a higher body mass index (BMI) and waist circumference were also at greater risk of being diagnosed with high grade tumours, and of dying, than those with lower BMI.
There was a 13% higher risk of high grade tumours for every 10cm increase in men's waist circumference. The risk of dying from prostate cancer was 18% higher for each additional 10cm.
The research, published in the journal BMC Medicine, used data from a European study into cancer and nutrition that included 141,896 men from 8 countries, including the UK.
Cancer grade and stage
The authors say that previous studies have not been able to establish a relationship between body size and prostate cancer risk – and in particular risk by tumour type – because they have not differentiated by how far tumours have spread, known as cancer stage, or by grade, a measure of how abnormal tumour cells are when compared to normal cells.
"The mechanisms underlying this association of height with aggressive disease are not fully understood," the researchers write. However, they speculate it might be related to early nutrition and growth.
The link with obesity could be due to changes in hormone levels in obese men that might increase the risk of developing aggressive cancer, they say. However, obese men have lower concentrations of prostate-specific antigens (PSAs), are less likely to undergo a biopsy, and are more likely to have larger prostates, making cancer detection more difficult. A reduced likelihood of early detection and treatment might lead to more cases of aggressive prostate cancer and a higher risk of dying from the disease, the researchers suggest.
Further research needed
Dr Jasmine Just, health information officer at Cancer Research UK, which helped fund the research, says in an emailed comment: "This study helps to untangle previous findings on prostate cancer risk factors. But it's still unclear if there is a link between being overweight or obese and an increased risk of aggressive prostate cancer.
"Further studies are also needed to understand if men who are overweight or obese might be at a higher risk of dying from prostate cancer, and if so why. It’s important to remember though that keeping a healthy weight can help men reduce the risk of 10 types of cancer, including bowel cancer."
In 2014, there were 46,690 new cases of prostate cancer and 11,287 deaths from the disease in the UK.