Phosphodiesterase Type 5 Inhibitors and the Risk of Melanoma Skin Cancer

Abstract

Background: The association between phosphodiesterase type 5 inhibitors (PDE5-Is), drugs used in the treatment of erectile dysfunction (ED), and melanoma skin cancer is controversial.

Objective: To assess whether the use of PDE5-Is is associated with an increased risk of melanoma skin cancer.

Design, setting, and participants: Using the UK Clinical Practice Research Datalink, we assembled a cohort of men newly diagnosed with ED between 1998 and 2014 and followed until 2015. PDE5-I exposure was considered as a time-varying variable lagged by 1 yr for latency purposes.

Outcome measurements and statistical analysis: Cox proportional hazards models were used to estimate adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) of incident melanoma associated with PDE5-I use overall and by number of prescriptions and pills received. Identical analyses were conducted for basal and squamous cell carcinoma, two cancers for which PDE5-related pathways are not thought to be involved.

Results and limitations: The cohort included 142 983 patients, of whom 440 were newly diagnosed with melanoma during follow-up (rate: 63.0 per 100 000 person-years). Compared with nonuse, PDE5-I use was not associated with an overall increased risk of melanoma (rates: 66.7 vs 54.1 per 100 000 person-years; HR: 1.18; 95% CI, 0.95-1.47). The risk was significantly increased among those who had received seven or more prescriptions and ≥25 pills (HR: 1.30 [95% CI, 1.01-1.69] and 1.34 [95% CI, 1.04-1.72], respectively). In contrast, there was no overall association with basal and squamous cell carcinoma, with an unclear association with numbers of prescriptions and pills received.

Conclusions: The use of PDE5-Is was not associated with an overall increased risk of melanoma skin cancer. The increased risks observed in the highest prescription and pill categories require further validation.

Patient summary: In this study, the use of phosphodiesterase type 5 inhibitors was not associated with an increased risk of melanoma skin cancer.

Keywords: Basal cell carcinoma; Erectile dysfunction; Melanoma skin cancer; Phosphodiesterase type 5 inhibitors; Squamous cell carcinoma.