Antihypertensive Medication as a Risk Factor For Basal Cell Carcinoma: A Nationwide Registry-based Case-control Study.

Hydrochlorothiazide has been associated with increased cutaneous squamous cell carcinoma risk. Meanwhile, its association with basal cell carcinoma (BCC) risk is controversial. The association between commonly prescribed antihypertensive medications and BCC risk in the Swedish population was investigated. All cases with a histopathologically verified BCC in Sweden during 2007-2017 and 2 matched controls per case were included in this nationwide, registry-based, case-control study. Information on prescribed anti-hypertensive drugs, comorbidities, co-medications, and socioeconomic factors was retrieved from nationwide registries. The odds of being treated with any of the chosen treatments in relation to BCC diagnosis were estimated. In total, 133,539 cases and 257,849 controls were studied. Thiazide-containing combination treatments (OR 1.09), angiotensin II receptor blockers (OR 1.09), calcium channel blockers (OR 1.09), and beta-blockers (OR 1.07) were associated with an increased BCC risk. Use of single-agent thiazide treat-ment did not affect BCC risk. In conclusion, statistically significant associations were found between several commonly prescribed antihypertensives and an increased BCC risk. Thiazide treatment affected BCC risk only when given as combination treatment, indicating that relevant adjunctive substances should be studied further in relation to BCC risk. Presently, it is suggested that prevention efforts focus on UV protection rather than altering antihypertensive treatments.