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.

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.

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.

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.