ABSTRACT
PURPOSE: Experimental evidence suggests that phosphodiesterase type 5 inhibitors may suppress tumor growth, postpone metastasis and prolong survival, but clinical data are lacking. We studied the effect of phosphodiesterase type 5 inhibitors on biochemical recurrence after radical prostatectomy for prostate cancer. MATERIALS AND METHODS: The study was comprised of 4,752 consecutive patients with localized prostate cancer treated with bilateral nerve sparing radical prostatectomy between January 2000 and December 2010. Of these patients 1,110 (23.4%) received phosphodiesterase type 5 inhibitors postoperatively while 3,642 (76.6%) did not. The risk of biochemical recurrence was compared between the phosphodiesterase type 5 inhibitor group and the nonphosphodiesterase type 5 inhibitor group. Cox multivariate proportional hazard models and confidence intervals were used to estimate the hazard ratio of biochemical recurrence associated with phosphodiesterase type 5 inhibitor use. Propensity score matched analysis was performed. RESULTS: Median followup was 60.3 months (IQR 36.7-84.5). Five-year biochemical recurrence-free survival estimates in the phosphodiesterase type 5 inhibitor vs nonphosphodiesterase type 5 inhibitor groups were 84.7% (95% CI 82.1-87.0) and 89.2% (95% CI 88.1-90.3), respectively (p=0.0006). Multivariate regression analysis showed that phosphodiesterase type 5 inhibitor use was an independent risk factor for biochemical recurrence (HR 1.38, 95% CI 1.11-1.70, p=0.0035) and this was also true after propensity score matching. CONCLUSIONS: Contrary to experimental data, the use of phosphodiesterase type 5 inhibitors after radical prostatectomy may adversely impact biochemical recurrence. Further studies are needed to validate our results.
