The association between prostatitis and risk of prostate cancer: a National Health Insurance Database study

Purpose: Inflammation is thought to affect the development of prostate cancer (PCa). By retrospectively investigating the database of the National Health Insurance Service, this study attempted to perform a relevant analysis of patients with prostatitis and PCa. Methods: Participants were aged ≥ 50 years. Patients diagnosed with prostatitis between 2010 and 2013 and matched controls were followed up until 2019. We selected controls with matched propensity scores for age, diabetes, hypertension, and the Charlson comorbidity index. Multivariate Cox regression analysis was conducted to determine the hazard ratio (HR) and 95% confidence interval (CI) of the association between prostatitis and PCa. The HR for PCa according to the presence of prostatitis was classified as acute, chronic, or other prostatitis. Results: A total of 746,176 patients from each group were analyzed. The incidence of PCa was significantly higher in the group with prostatitis (1.8% vs 0.6%, p < 0.001). The HR for PCa was significantly higher in patients with prostatitis (HR 2.99; 95% CI 2.89–3.09, p < 0.001). The HR for PCa was significantly higher in acute prostatitis than in chronic prostatitis (3.82; 95% CI 3.58–4.08; p < 0.001; HR 2.77; 95% CI 2.67–2.87, p < 0.001). The incidence of all-cause death in patients diagnosed PCa was significantly lower in prostatitis group (HR 0.58, 95% CI 0.53–0.63, p < 0.001). Conclusion: Prostatitis is associated with an increased incidence of PCa. Acute prostatitis is associated with higher risk of PCa than chronic prostatitis. Clinicians should inform patients with prostatitis that they may have an increased risk of diagnosing PCa, and follow-up is needed.