Use of Phosphodiesterase 5 Inhibitors Is Associated With Lower Risk of Colorectal Cancer in Men With Benign Colorectal Neoplasms

Phosphodiesterase 5 (PDE5) inhibitors have been proposed to have chemopreventative effects on colorectal cancer (CRC), although data are needed from population-based studies. We performed a nationwide cohort study to investigate the association between the use of PDE5 inhibitors and the risk of CRC in men with benign colorectal neoplasms.We identified men who received a diagnosis of benign colorectal neoplasm from July 2005 through March 2015 who were listed in the Swedish Hospital Discharge Register. We linked data with those from other national Swedish registers to obtain information about the prescription of PDE5 inhibitors and CRC diagnoses. Cox regression was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs).A total of 4823 patients were prescribed PDE5 inhibitors during the study period; the incidence rate of CRC was 2.64 per 1000 person-years for men prescribed PDE5 inhibitors compared with 4.46 per 1000 person-years for men without a prescription. We found a significant negative association between PDE5 inhibitor use and risk of CRC (adjusted HR, 0.65; 95% CI, 0.49-0.85); the decreased risk of CRC was associated with an increased cumulative dose of PDE5 inhibitors (P = .003). PDE5 prescription was associated with greater reduction in risk of advanced-stage CRC (adjusted HR, 0.61; 95% CI, 0.37-1.00) than early-stage CRC (adjusted HR, 0.70; 95% CI, 0.50-0.98), but the difference was not significant.In a nationwide population-based study of men with a diagnosis of benign colorectal neoplasm in Sweden, we found evidence that use of PDE5 inhibitors is associated with a reduced risk of CRC. Further studies are needed to confirm the observed association.