Photosensitizing antihypertensive medication and risk of skin cancer among postmenopausal women.

BACKGROUND: Few prospective studies exist with an evaluation of a dose-response relationship between use of some photosensitizing antihypertensive medications and skin cancer.

PATIENT AND METHODS: We used prospective data from the Women's Health Initiative Observational Study to investigate the association between antihypertensive use and risk of non-melanoma skin cancer (NMSC) and melanoma in postmenopausal women aged 50-79 years at baseline (n  =  64,918). Multivariable Cox proportional hazards regression models were used and hazard ratios (HRs) and 95 confidence intervals (CIs) were calculated.

RESULTS: 8,777 NMSC and 1,227 melanoma cases were observed. Use of antihypertensives (HR [95% CI]: 1.12 [1.07-1.18]), ACE inhibitors (1.09 [1.01-1.18]), calcium channel blockers (1.13 [1.05-1.22]), diuretics (1.20 [1.12-1.27]), loop diuretics (1.17 [1.07-1.28]), and thiazides (1.17 [1.03-1.33]) were each associated with higher NMSC risk. NMSC risk linearly increased with use of multiple antihypertensives (p-trend  =  0.02) and with longer duration of use (p-trend < 0.01). Antihypertensives (1.15 [1.00-1.31]), angiotensin-II receptor blockers (1.82 [1.05-3.15]), and diuretics (1.34 [1.13-1.59]) were each associated with elevated melanoma risk. Effect modification by solar radiation exposure was found between antihypertensive use and incidence of melanoma (p-interaction  =  0.02).

CONCLUSIONS: Use of antihypertensives overall, and several individual classes thereof, were associated with higher incidence of NMSC and melanoma with dose-response relationship.