Hydrochlorothiazide use poses risk of cutaneous squamous cell carcinoma among diabetics

Type 2 diabetes (T2D) patients exposed to hydrochlorothiazide for more than 2 years appear to be at higher risk of cutaneous squamous cell carcinoma (cSCC), as reported in a recent study.

Researchers estimated the risk of cSCC in relation to hydrochlorothiazide use among 71,648 T2D patients after linking the benchmarking database in Dutch primary care, the Netherlands Cancer Registry, and the Dutch Personal Records Database. None of the patients had a history of skin cancer at baseline.

A total of 1,409 cSCC events occurred over a follow-up of 679,789 person-years. Of these, 23 were among thiazide-like diuretics users.

In a multivariable Cox proportional hazards model, hydrochlorothiazide use conferred an increased risk of cSCC compared with nonuse. The risk increase was 18 percent with ≤2 years of use (adjusted hazard ratio [HR], 1.18, 95 percent confidence interval [CI], 1.00–1.40), 57 percent with 2–4 years of use (adjusted HR, 1.57, 95 percent CI, 1.32–1.88), and rose twofold with >4 years of use (adjusted HR, 2.09, 95 percent CI, 1.73–2.52).

Conversely, an additional year of thiazide-like diuretic use was associated with a 10-percent protection against the risk of cSCC (adjusted HR, 0.90, 95 percent CI, 0.79–1.03).

The findings suggest that among T2D patients, a potential increased risk of cSCC should be considered when prescribing hydrochlorothiazide and that thiazide-like diuretics may offer a safer alternative.