Researchers using a new method of assessing risk factors for prostate cancer have found an intriguing link between a lack of physical activity and an increased risk of this condition.
Prostate cancer is the second most common type of cancer among males both in the United States and worldwide.
According to data from the National Cancer Institute (NCI), by the end of 2019, there will have been an estimated 174,650 new cases of prostate cancer in the U.S. alone.
Despite the number of people that this cancer affects every year, specialists still have insufficient knowledge about the risk factors that may play a role in its development.
The NCI cite a mix of modifiable and nonmodifiable factors, including age, a family history of prostate cancer, and the levels of vitamin E, folic acid, and calcium in the body.
Yet there may be other lifestyle-related factors at play, and investigators are hard at work to uncover them.
Recently, a team of researchers from the University of Bristol and Imperial College London in the United Kingdom — alongside colleagues from other academic institutions across the globe — have used a different approach to try to find out more about prostate cancer risk factors.
In their new study, the findings of which now appear in the International Journal of Epidemiology, the investigators used a method called “Mendelian randomization.”
Mendelian randomization allows researchers to look at genetic variations to assess causal relationships between various potential risk factors and the development of certain outcomes — in this case, prostate cancer.
Physical activity may more than halve risk
In their study, the researchers identified potential risk factors for prostate cancer through the World Cancer Research Fund’s (WCRF) 2018 systematic review of the evidence.
They also had access to the medical information of 79,148 participants with prostate cancer, as well as 61,106 participants without cancer who acted as the controls.
The analysis revealed that individuals with a genetic variation that increased their likelihood of being physically active had a 51% lower risk of prostate cancer than people who did not have this genetic variation.
Moreover, the researchers explain that “physical activity,” in this case, refers to all forms of activity, not just exercise.
Following on from this, the study authors conclude that interventions encouraging males to ramp up their levels of physical activity may have a protective effect against this widespread form of cancer.
“This study is the largest-ever of its kind, which uses a relatively new method that complements current observational research to discover what causes prostate cancer,” notes study co-author Sarah Lewis, Ph.D.
“It suggests that there could be a larger effect of physical activity on prostate cancer than previously thought, so will hopefully encourage men to be more active.”
Sarah Lewis, Ph.D.
Anna Diaz Font, who is head of research funding at WCRF — which, alongside Cancer Research U.K., funded this study — emphasizes the importance of the current findings.
“Up till now, there has only been limited evidence of an effect of physical activity on prostate cancer. This new study looked at the effect of 22 risk factors on prostate cancer, but the results for physical activity were the most striking,” she says.
The study’s findings, Diaz Font believes, “will pave the way for even more research, where similar methods could be applied to other lifestyle factors, to help identify ways men can reduce their risk of prostate cancer.”