Chronic inflammation appears to be positively correlated with prostate cancer, particularly high-grade disease, according to recent findings.
To determine the possible correlation between inflammation in benign tissue and prostate cancer risk, Elizabeth A. Platz, ScD, MPH, professor of epidemiology at Johns Hopkins Bloomberg School of Public Health, and colleagues evaluated 191 men with prostate cancer sampled from the Prostate Cancer Prevention Trial, as well as 209 controls frequency-matched at baseline to cancer cases for age, family history of prostate cancer and treatment arm.
Elizabeth A. Platz
All participants were screened for prostate cancer by PSA and digital rectal examination during yearly visits.
“We had the unique opportunity to investigate biopsy tissue from patients who had no indication to prompt a biopsy,” Platz said in a press release. “Participants in the [Prostate Cancer Prevention Trial] who were not diagnosed with prostate cancer during the trial were recommended to undergo prostate biopsy at the end of that trial, which meant that prostate tissue was available not just for men who had the diagnosis of prostate cancer, but also for those who did not have the diagnosis.”
The researchers utilized the hematoxylin and eosin-stained slides that were utilized to diagnose or rule out prostate cancer. They sampled a mean of two stained slides, to which six to 10 needle biopsy cores were mounted, per participant (16% had one, 68.5% had two and 15.5% had three slides). Associations between benign tissue inflammation and prostate cancer risk were estimated via logistic regression.
Platz and colleagues found that 86.2% of cancer cases and 78.2% of controls had at least one biopsy core showing inflammation in benign tissue, the majority of which was chronic. Men with at least one biopsy core showing inflammation had a 1.78 (95% CI, 1.04-3.06) times higher odds of prostate cancer vs. men with no cores showing inflammation.
High-grade prostate cancer was more strongly correlated with inflammation (Gleason sum 7-10, n=94, OR=2.24; 95% CI, 1.06-4.71). These findings were consistent when restricting to those cases and controls where inflammation was least likely to precipitate a biopsy recommendation because the patients’ PSA was low (<2 ng/mL at biopsy).
“We found that men who had at least one biopsy core with inflammation had a higher likelihood of having high-grade prostate cancer compared with those who did not have any inflammation in their biopsy tissue,” Platz said. “While we know that inflammation is common in prostate tissue from men who have some indication to prompt a biopsy, such as high PSA or an abnormal digital rectal examination, we were surprised to find that the prevalence of chronic inflammation in the men who didn’t have any such indication was really high, about 78%.”
Disclosure: One researcher is a consultant/advisory board member of Bristol-Myers Squibb and Compugen, and another is a consultant/advisory board member of GlaxoSmithKline.