Cancer is More Likely When There’s Inflammation in Normal Prostate Tissue
Platz and De Marzo: Inflammation is a warning sign that potentially lethal cancer may be present.
Why is the prostate prone to chronic inflammation, and what role, if any, does this inflammation play in the development of prostate cancer? These are questions that epidemiologist Elizabeth Platz, Sc.D., M.P.H., and pathologist Angelo De Marzo, M.D., Ph.D., have been investigating for 15 years, and in their lates t research, they have found that men who have inflammation in normal prostate tissue may be nearly twice as lik ely to have cancer, and to have cancer of a higher grade.
This research doesn’t prove that inflammation actually causes prostate cancer, but it is a w arning sign that potentially lethal cancer might be present — and it also r epresents an exciting potential avenue for preventing the disease.
For years, De Marzo, Professor of Pathology, Oncology, and Urology, has seen inflammatory cells in prostate biopsies, radical prostatectomy specimens, and in tissue resected for treatment of BPH (benign enlargement of the prostate). “There are infections and diseases associated with inflammation in liver, stomach, and colon cancers,” he says, “and it is possible that inflammation could serve as an initiator and/or promotor of prostate cancer, as well.”
In a recent study, published in Cancer Epidemiology, Biomarkers, and Prevention, Platz and De Marzo investigated the connection between inflammation and prostate cancer. “We wanted to make sure that there was no potential for bias,” says Platz, Professor of Epidemiology, Oncology, and Urology. In the U.S. and other countries where PSA testing is routine, it is possible that the men who get prostate biopsies do so because inflammation has caused their regularly tested PSA to go up. “Prostate cancer is more likely to be detected in these men; thus, we chose to look for cancer in men who had no apparent cause to undergo a biopsy.”
In this study, De Marzo and Platz studied men in a setting where this bias would be less likely: SWOG’s Prostate Cancer Prevention Trial. “The men who were not diagnosed with prostate cancer during this trial were recommended to have a prostate biopsy at the end, even if they had a normal PSA and digital rectal examination,” says Platz. “This meant that we had access to prostate tissue from men who had no suspicious signs that cancer might be present.”
The study included 191 men with prostate cancer that had been detected by biopsy, and 209 matched controls. Bora Gurel, M.D., a pathology fellow at the time of the work and the paper ’s first author, looked for inflammation in benign tissue in the biopsy cores. He recorded the presence of any inflammatory cells and determined the proportion of the total benign biopsy cor e area that showed any inflammatory cells. “It turned out that chronic inflammation was very common within the prostate,” says De Marzo. The scientists found inflammation in about 86 percent of the men with prostate cancer, but also in about 78 percent of the men who had not been diagnosed with cancer. “Men who had inflammation in at least one biopsy core had higher odds of having prostate cancer, and even higher odds of having higher-grade prostate cancer (Gleason 7-10).” Even in men with low PSA levels (less than 2 ng/ml), this association between inflammation and both total and higher-grade prostate cancer remained.
“Men who had inflammation in at least one biopsy core had higher odds of having prostate cancer, and even higher odds of having highergrade prostate cancer.”
In related news: In 2014, Platz was named a Mentor of Excellence by the Prostate Cancer Foundation, and she also received a Teaching Award from the Brady Urological Institute. n