Phosphodiesterase type 5 inhibitors and risk of melanoma: A meta-analysis

BackgroundThe association between phosphodiesterase type 5 (PDE5) inhibitors and melanoma risk is controversial.ObjectiveWe quantify the association between use of PDE5 inhibitors and melanoma.MethodsWe systematically searched PubMed, Embase, the Cochrane Central Register of Controlled Trials, Web of Science, and ClinicalTrials.gov for studies that were conducted up to July 13, 2016, and evaluated the association between PDE5 inhibitors and skin cancer. Random effects meta-analyses were used to calculate the adjusted odds ratio (OR) with the 95% confidence interval (CI).ResultsFive observational studies were included. Compared with PDE5 inhibitor nonuse, PDE5 inhibitor use was slightly but significantly associated with an increased risk for development of melanoma (OR, 1.12; 95% CI, 1.03-1.21) and basal cell carcinoma (OR, 1.14; 95% CI, 1.09-1.19) but not squamous cell carcinoma. For melanoma risk, none of the prespecified factors (dose of PDE5 inhibitor, study design, and study region) significantly affected the results (P > .05). Our sensitivity analysis confirmed the stability of the results.LimitationsWe included only observational studies, which had some heterogeneities and inconsistent controlling for potential confounders.ConclusionsUse of PDE5 inhibitors may be associated with a slightly increased risk for development of melanoma and basal cell carcinoma but not squamous cell carcinoma. However, further large well-conducted prospective studies with adequate adjustment for potential confounders are required for confirmation.