A counterbalance to genetic risk
Dr. Plym observed that the rate of lethal disease in men with the best lifestyle scores matched the rate for the study population as a whole (3%), suggesting that healthy lifestyle may counterbalance high genetic risk.
She added that previous research has confirmed physical activity as a protective factor, but more study is needed to shed light on the relative benefit of the healthy lifestyle components.
In addition, further research is necessary to explain why the benefit was limited to lethal prostate cancer risk in men with the highest genetic risk.
Dr. Plym speculated that the genetic variants contributing to a high PRS may also be the variants that have the strongest interaction with lifestyle factors. For men with a genetic predisposition to prostate cancer, she added, these findings underscore the potential value of surveillance.
“Our findings add to current evidence suggesting that men with a high genetic risk may benefit from a targeted prostate cancer screening program, aiming at detecting a potentially lethal prostate cancer while it is still curable,” she said.
Charles Swanton, MBPhD, of the Francis Crick Institute and UCL Cancer Institute in London, raised the possibility that competing risk issues could be at play.
If a healthy lifestyle leads to longer life, he asked, does that make it more likely that patients will live long enough to die from their prostate cancer because they are not dying from cardiovascular disease, complications of diabetes, etc.? In that case, is the healthy lifestyle really affecting prostate cancer at all?
Dr. Plym responded that, among those in the highest genetic risk group with an unhealthy lifestyle, the increased risk for prostate cancer exceeded the risk for other illnesses.
This study was funded by the DiNovi Family Foundation, the National Cancer Institute, the William Casey Foundation, the Swedish Society for Medical Research, and the Prostate Cancer Foundation. Dr. Plym declared no conflicts of interest. Dr. Swanton disclosed relationships with numerous companies, including Pfizer, Novartis, and GlaxoSmithKline.
