Researchers have found a link between chronic inflammation in prostate tissue, which is when the body's immune system is in a constant state of high alert, and aggressive prostate cancer.
The finding could lead to more studies on how to prevent or treat prostate cancer, which is the second most common form of cancer for American men.
"What we've shown in this observational study is a clear association between prostate inflammation and prostate cancer, although we can't prove that inflammation is a cause of prostate cancer," study researcher Elizabeth A. Platz, Sc.D., M.P.H., of the Johns Hopkins Kimmel Cancer Center in Maryland, said in a press release.
The findings were published Friday in the journal Cancer Epidemiology, Biomarkers & Prevention.
Platz and her team culled their data from the placebo group of the Southwest Oncology Group's Prostate Cancer Prevention Trial, a long-term study that tested a drug for prostate cancer prevention. Researchers for the Southwest Trial had taken prostate tissue biopsy samples from the placebo group, even if they didn't show potential signs of prostate cancer at the time.
Platz and team then identified 191 men who developed prostate cancer and 209 men without cancer from the Southwest Oncology Group trial and examined their prostate tissue samples for signs of inflammation. Eighty-six percent of the subjects who developed prostate cancer had at least one tissue sample with signs of inflammation, while 78 percent of men with no cancer had signs of inflammation.
Researchers found this difference statistically significant, noting that men whose tissue samples had shown signs of inflammation had 1.78 times the odds of developing prostate cancer, and 2.24 times the odds of developing aggressive prostate cancer in particular.
This study is different from others in that researchers were able to examine tissue samples from men who normally wouldn't have needed a biopsy. This change rules out bias that would normally be present in studies of prostate cancer and inflammation.
Platz studied a type of prostate inflammation that is asymptomatic, which means that men won't even know they have it. This asymptomatic inflammation is extremely common, explained Platz in an interview with The Huffington Post, so more study is needed to see if and how it influences risk for prostate cancer in the future.
And that research is already underway: Platz has begun working on a prospective study to confirm the link between inflammation and prostate cancer.
"If our findings hold up, we need to figure out how to prevent inflammation in the prostate and how to intervene on inflammation in the prostate," Platz said. "At this time, it's not known."
So what can men take away from the study's findings? Not much right now, Platz admitted.
"There's nothing that men can do based on our current study to change their risk of prostate cancer," said Platz. "They should be alert to future research and be aware of risk factors for cancer and poor health in general. Men need to focus on their overall well-being by not smoking, or not being overweight or obese."