A new paper from researchers at Harvard University confirms earlier evidence that exercise is protective against prostate cancer mortality.
In this new study published in the October 2018 issue of European Urology, men who engaged most frequently in vigorous activities had a 30% lower risk of advanced prostate cancer, a 25% lower risk of developing advanced prostate cancer, and a 25% lower risk of dying from prostate cancer, compared to men who exercised the least. Data was gathered from 49,160 men aged 40-75 enrolled in the Professionals Follow-up Study who were tracked from 1986 to 2012. Of these participants 6,411 developed prostate cancer and 888 died from the disease.
Intense exercise in this study included things like bicycling, swimming, heavy outdoor work and playing sports like tennis. The men in the highest category of exercise engaged in the equivalent of a 25-minute run daily.
Past prospective cohort studies have also suggested that vigorous exercise is associated with lower risk of prostate cancer specific mortality. In terms of metabolic equivalent task (MET) values, vigorous exercise means MET>6. This means jogging, biking, or swimming or exercise of similar intensity as listed in the current paper. In a 2011 analysis of data from the same cohort of men, the Health Professionals Follow-up, Kenfield and other Harvard researchers reported that men who performed 3+ hours/week of vigorous activity had a 61% lower risk of dying from prostate cancer when compared to men who exercised less than 1 hour per week.1
Erin Van Blarigan working with this same Harvard team, reported similar results in 2011 after analyzing data from the CAPSURE cohort: men who walked briskly (≥3 mph) three or more hours per week had a 57% lower risk of prostate cancer recurrence compared with men who walked less than 3 hours a week at an easy pace (< 2 mph).2
Bonn reported similar effects in 2015 from a cohort of 4,623 men with localized prostate cancer. Men who either walked or biked ≥20 min/day versus doing either for less than 20 minutes a day was associated with a 36% decrease in prostate cancer mortality.3
In a 2015 paper, again with this Harvard group, Van Blarigan explained in part why exercise might be so beneficial in prostate cancer. Exercise affects tumor morphology; it literally changes the architecture of the tumors, leading to more regularly shaped blood vessels in the tumors. Microvessel morphology was examined in men with prostate cancer and compared to activity levels (n=571). Vigorous walking was associated with “… larger, more regularly shaped blood vessels compared with those of men who walked at a less than brisk pace.”4
This newest study stands out not just because it was bigger and had more participants generating data but also because the researchers were this time able to analyze pathology reports and examine molecular subtyping data. In this study they were able to focus attention on a common genetic change in prostate tumors called TMPRSS2:ER. This molecular change is present in about half of prostate cancer patients. Exercise appeared to lower risk of developing these TMPRSS2:ERG positive tumor types.5
One might wish that science researchers could consult some sort of focus group before deciding on these names and their resultant acronyms. No matter how important this genetic shift is proven to be in the future, this TMPRSS2:ERG is never going to roll easily out of my mouth.
Lucky for us in the research “… ERG [is](i.e., a surrogate of ERG fusion genes)” and one can come up with a simple vocalization that will suffice, at least when reading to oneself, as a stand in. ERG+ prostate cancers are more influenced by insulin like growth factor-1 receptor (IGF-1R) status. High levels of IGF-1R in ERG + prostate cancer nearly tripled the risk the cancer would be fatal.6
Harvard researchers are currently recruiting men with treatment resistant metastatic prostate cancer for a randomized research study on various exercise regimes to see if working out will improve long-term prognosis, which at this time is poor. This is not the study one would want to be randomized into the control group; better to simply start exercising on your own than sign up for this one.
