News study reports that men with prostatitis symptoms (all kinds of prostatitis, not just CP/CPPS) have a slightly higher incidence of prostate cancer than normal men (5% vs 2%), but the authors speculate this could be because of the additional testing men with prostatitis undergo, and furthermore comment that the differences between prostatitis patients and those with no history of prostatitis were "not significant" and may be "coincidental".
Based on the present data, it is possible to suggest that the increased incidence of prostate cancer among men with prostatitis symptoms compared with that among men with no symptoms may be due to a larger number of prostate cancer diagnostic examinations based on the patients symptoms.
To conclude, after 15 years of follow-up subsequent to self-reported prostatitis, no evidently increased incidence of prostate cancer was detected in the present cohort of Finnish men. Despite the higher percentage of prostate cancer among men with prostatitis symptoms compared with that among men with no symptoms, the SIR (standardized incidence ratio) of prostate cancer among men with prostatitis symptoms was within the expected range of values. It may be suggested that the higher percentage of prostate cancer among men with prostatitis symptoms compared with that among men without symptoms is due to the low SIR of prostate cancer cases among men without prostatitis symptoms, and it may also be due to more frequent prostate cancer diagnostic examinations based on symptoms. The present results do not support extensive diagnostic interventions in order to detect possible prostate cancer among men with prostatitis symptoms, considering that the clinical characteristics of prostate cancer did not differ between men with and without prostatitis symptoms.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4950901/