IMPORTANCE: The RAS/RAF/mitogen-activated protein kinase and extracellular signal-regulated kinase (ERK) kinase/ERK cascade plays a crucial role in melanoma cell proliferation and survival.
Sildenafil citrate (Viagra) is a phosphodiesterase (PDE) 5A inhibitor commonly used for erectile dysfunction. Recent studies have shown that BRAF activation down-regulates PDE5A levels, and low PDE5A expression by BRAF activation or sildenafil use increases the invasiveness of melanoma cells, which raises the possible adverse effect of sildenafil use on melanoma risk.
OBJECTIVE: To evaluate the association between sildenafil use and risk of incident melanoma among men in the United States.
DESIGN, SETTING, AND PARTICIPANTS: Our study is a prospective cohort study. In 2000, participants in the Health Professionals' Follow-up Study were questioned regarding sildenafil use for erectile dysfunction. Participants who reported cancers at baseline were excluded. A total of 25,848 men remained in the analysis.
MAIN OUTCOMES AND MEASURES: The incidence of skin cancers, including melanoma, squamous cell carcinoma (SCC), and basal cell carcinoma (BCC), was obtained in the self-reported questionnaires biennially. The diagnosis of melanoma and SCC was pathologically confirmed.
RESULTS: We identified 142 melanoma, 580 SCC, and 3030 BCC cases during follow-up (2000-2010). Recent sildenafil use at baseline was significantly associated with an increased risk of subsequent melanoma with a multivariate-adjusted hazard ratio (HR) of 1.84 (95% CI, 1.04-3.22). In contrast, we did not observe an increase in risk of SCC (HR, 0.84; 95% CI, 0.59-1.20) or BCC (1.08; 0.93-1.25) associated with sildenafil use. Moreover, erectile function itself was not associated with an altered risk of melanoma. Ever use of sildenafil was also associated with a higher risk of melanoma (HR, 1.92; 95% CI, 1.14-3.22). A secondary analysis excluding those reporting major chronic diseases at baseline did not appreciably change the findings; the HR of melanoma was 2.24 (95% CI, 1.05-4.78) for sildenafil use at baseline and 2.77 (1.32-5.85) for ever use.
CONCLUSIONS AND RELEVANCE: Sildenafil use may be associated with an increased risk of developing melanoma. Although this study is insufficient to alter clinical recommendations, we support a need for continued investigation of this association.
Written by:
Wen-Qing Li, PhD;1,2 Abrar A. Qureshi, MD, MPH;1,2,3 Kathleen C. Robinson, PhD;4,5 Jiali Han, PhD1,3,6,7,8,9 Are you the author?
1Department of Dermatology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
2Department of Dermatology, Rhode Island Hospital, Warren Alpert Medical School, Brown University, Providence
3Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
4Department of Dermatology, Massachusetts General Hospital, Boston
5Graduate Program in Biological and Biomedical Sciences, Harvard Medical School, Boston, Massachusetts
6Department of Epidemiology, Harvard School of Public Health, Boston, Massachusetts
7Department of Epidemiology, Richard M. Fairbanks School of Public Health, Indiana University, Indianapolis
8Melvin and Bren Simon Cancer Center, Indiana University, Indianapolis
9Department of Epidemiology, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China
Reference: JAMA Intern Med. 2014 Jun;174(6):964-70
doi: 10.1001/jamainternmed.2014.594
PubMed Abstract
PMID: 24710960
