Inflammatory bowel diseases (Crohn’s disease, ulcerative colitis, or indeterminate colitis) are immune-mediated conditions that, if not well controlled, cause inflammation. It is theorized that chronic inflammation may play a role in the development of prostate cancer. Prostatitis is often found at the same time as prostate cancer. What is not well established is whether conditions such as inflammatory bowel disease, which cause inflammation in the body, may also contribute to the risk of cancer, including prostate cancer. A retrospective cohort study from Northwestern University Feinberg School of Medicine in Chicago included 1,033 male patients with inflammatory bowel disease, then matched and compared them with 9,306 men who did not have inflammatory bowel disease. All patients included in the study underwent at least one PSA test. Retrospective cohort studies look at already existing data and try to identify risk factors for certain conditions. A retrospective study looks at past health records to see what outcomes have occurred over a long period of time. The researchers found that after 10 years, 4.4% of patients with inflammatory bowel disease were diagnosed with prostate cancer. PSA levels in men with inflammatory bowel disease were also found to be higher than in men without such disease. The study authors found no link between drugs used to treat inflammatory bowel disease (namely those that suppress the immune system) and an increased risk of prostate cancer. However, they note that they did not take into account how long the men diagnosed with prostate cancer had been taking drugs for inflammatory bowel disease. Another point the researchers describe is that men with inflammatory bowel disease may visit their doctors more often than men who do not have inflammatory bowel disease. In addition, men with inflammatory bowel disease are more likely to undergo an examination such as a digital rectal exam than men who do not have inflammatory bowel disease. For this reason, it may be that men with inflammatory bowel disease are more often diagnosed with prostate cancer because they are screened for it more often. Meta-analysis is a combination of the results of several research methods of statistics to test one or several interrelationships of scientific hypotheses. In a meta-analysis, scientists take into account several studies on a particular topic and compare all the results. They then do a mathematical analysis to understand how all the results from the different studies come together to support their hypothesis. There are nine studies,which included a meta-analysis of the relationship between prostate cancer and inflammatory bowel disease. What the results show is that men with ulcerative colitis in particular are at a significantly increased risk of developing prostate cancer. The same association was not found in men with Crohn’s disease. References: 1. National Institute on Aging. Prostate problems. National Institutes of Health 2. Burns JA, Weiner AB, Catalona WJ, et al. Inflammatory bowel disease and the risk of prostate cancer 3. Verywell Health. Inflammatory Bowel Disease and the Risk of Prostate Cancer