Prostate cancer incidence in men with self-reported prostatitis after 15 years of follow-up

Controversy exists regarding a possible association between prostatitis and prostate cancer. To further evaluate the incidence of prostate cancer following prostatitis, a study of prostate cancer incidence in a cohort of Finnish men was performed. The original survey evaluating self-reported prostatitis was conducted in 1996-1997. A database review was conducted focusing on prostate cancer diagnoses in the cohort. In 2012, there were 13 (5.2%) and 27 (1.8%) prostate cancer cases among men with (n=251) and without (n=1,521) prostatitis symptoms, respectively. There were no significant differences in age, primary therapy distribution, prostate-specific antigen levels, Gleason score, clinical T-class at the time of prostate cancer diagnosis, or time lag between the original survey and prostate cancer diagnosis. The standardized incidence ratio (SIR) of prostate cancer was 1.16 [95% confidence interval (CI), 0.62-1.99] and 0.44 (95% CI, 0.29-0.64) among men with and without prostatitis symptoms, respectively. After 15 years of follow-up subsequent to self-reported prostatitis, no evident increase in incidence of prostate cancer was detected among Finnish men with prostatitis symptoms. The higher percentage of prostate cancer among men with prostatitis symptoms appears to be due to coincidentally low SIR of prostate cancer among men without prostatitis symptoms, and may additionally be due to increased diagnostic examinations. Further research is required to confirm this speculation.