A study published in the open access journal BMC Medicine states that men who are tall and obese are at a higher risk of high-grade prostate cancer and prostate cancer death.
According to the team of researchers from the University of Oxford, height was not associated with the overall prostate cancer risk, but, with the addition of every 10 cm (3.9 inches) of height, the risk being diagnosed with aggressive prostate cancer and then death caused due to the disease increases by 21% and 17% respectively.
The study also found that those with a higher Body Mass Index (BMI) had increased risk of high-grade tumors and death from prostate cancer. It is cautioned by the authors of the study that using BMI as a measure of overweight and obesity might be less sensitive in older adults, than in younger cohorts. As the participants of the study had an average age of 52 years or above, this might lead to an underestimation of the prevalence of obesity in their results.
Waist circumference is considered as a more accurate measure of obesity in older adults than BMI, and the study found that with every increase of 10 cm of the waist circumference, there was a 13% increased risk of high-grade cancer and 18% greater risk of death from prostate cancer.
The lead author of the study, Dr. Aurora Perez-Cornago, hopes that the association of taller men and increased prostate cancer risk found in their results will provide an insight into the underlying mechanism of prostate cancer development, for example early nutrition and growth.
In their findings, they also observed that a healthy body weight was linked to a decreased risk in death caused by prostate cancer and diagnosis of high-grade prostate cancer. This lead Dr Perez-Cornago to believe that the relationship between obesity and a higher rate of aggressive prostate cancer in men, seen in the study, could be caused by alterations in their hormone levels. However, he notes that differences in prostate cancer detection could also be contributing to the results seen.
Data from the European Prospective Investigation into Cancer and Nutrition (EPIC) which is a prospective European cohort with 141,896 men from 8 different countries (Denmark, Italy, the Netherlands, Spain, Sweden, the UK, Germany, and Greece) were used in the study. Details of 7,024 incident prostate cancers, 726 high-grade and 1,388 advanced-stage prostate cancers, and 934 prostate cancer deaths were included in the data.
The study, which investigates the links between height and obesity with prostate cancer, is the first of its kind that differentiates between high-grade and advanced stage tumors. In most of the prior studies, the tumors were not grouped into sub-types based on its stage (how far the tumor had spread) and grade (how abnormal tumor cells were, when compared to normal cells). Those factors were grouped under combined categories of aggressive or non-aggressive tumors.
Dr. Perez-Cornago commented, "Our data illustrate the complex association of adiposity and prostate cancer, which varies by disease aggressiveness. These results emphasize the importance of studying risks for prostate cancer separately by stage and grade of the tumor. They may also inform strategies for prevention, but we need to do further work to understand why the differences in risk exist.".
More research should be carried out to know if the increased risk of aggressive prostate cancer in men with obesity is due to an increased risk of developing aggressive forms of the disease or to differences in prostate cancer detection.