Hydrochlorothiazide Use and Risk of Skin Cancer: A Population-based
Retrospective Cohort Study
Abstract
Purpose Exposure of hydrochlorothiazide (HCTZ) has been linked
to the increase of skin cancer in the Caucasian population, especially
for the squamous cell carcinoma (SCC) but not for basal cell carcinoma
(BCC). This study aimed to evaluate the risks of skin cancer between
patients receiving HCTZ and those receiving other antihypertensives.
Methods This retrospective cohort study was derived from the
National Health Insurance Database in Taiwan. We enrolled patients aged
20 years and older who newly receiving antihypertensive medications
between 2004 - 2015. We calculated the medication possession ratio (MPR)
of the first two years of treatment for patient enrollment and treatment
classification, in which patients with MPR above 80% were enrolled and
patients were subsequently categorized into receiving HCTZ, other
thiazide diuretics, non-thiazide diuretics, and non-diuretic
antihypertensives. The Cox proportional hazards model was used to
evaluate the risk of skin cancer, and further divided into SCC, and BCC.
Results Our study enrolled 41,086, 27,402, 19,613, and 856,782
patients receiving HCTZ, other thiazide diuretics, non-thiazide
diuretics, and non-diuretic antihypertensives, respectively. We found
BCC risks were similar when comparing HCTZ with other thiazides
(adjusted hazard ratio, 0.84; 95% CI: 0.54-1.33), non-thiazide
diuretics (0.93; 0.51-1.67), and non-diuretic antihypertensives (0.91;
0.66-1.26). Higher SCC risk was observed in the HCTZ group, compared to
other thiazide (1.24; 0.74-2.08), non-thiazide diuretics (1.32; 0.70-
2.51), and non-diuretic antihypertensives (1.23; 0.87-1.73), although
the differences were not statistically significant. Conclusions
We conclude that skin cancer need not be of major concern to physicians
when prescribing antihypertensives for an Asian population.