Many antihypertensive drugs (ADs) are photosensitizing, heightening reactivity of the skin to sunlight. Photosensitizing ADs have been associated with lip cancer, but whether they impact cutaneous squamous cell carcinoma (cSCC) risk is unknown.
To examine the association between AD use and cSCC risk among a cohort of non-Hispanic whites with hypertension enrolled in a comprehensive integrated healthcare delivery system in northern California (n=28,357).
Electronic pharmacy data were used to determine exposure to ADs, which were classified, based on published literature, as photosensitizing (alpha-2 receptor agonists and diuretics [loop, potassium-sparing, thiazide, and combination]), non-photosensitizing (alpha-blockers, beta-blockers, central agonists, and angiotensin receptor blockers), or unknown (angiotensin converting enzyme inhibitors, calcium channel blockers, vasodilators, and other combinations). We identified patients who developed a cSCC during follow-up (n=3,010). We used Cox modeling to estimate adjusted hazard ratios (aHR) and 95% confidence intervals (CI). Covariates included age, sex, smoking, comorbidities, history of cSCC and actinic keratosis, survey year, healthcare utilization, length of health-plan membership, and prior history of photosensitizing AD use.
Compared with non-use of ADs, risk of cSCC was increased with ever use of photosensitizing ADs (aHR=1.17, 95% CI 1.07-1.28) and ever use of ADs of unknown photosensitizing potential (aHR=1.11, 95% CI 1.02-1.20), whereas no association was seen with ever use of non-photosensitizing ADs (aHR=0.99; 95% CI, 0.91-1.07). In addition, there was a modest increased risk with increasing number of prescriptions for photosensitizing ADs (aHR=1.12, 95% CI 1.02-1.24, aHR=1.19, 95% CI 1.06-1.34, aHR=1.41, 95% CI 1.20-1.67 for 1-7, 8-15 and 16+ fills, respectively).
These findings provide moderate support for an increased cSCC risk among individuals treated with photosensitizing ADs. This article is protected by copyright. All rights reserved.