The following is a summary of “Hydrochlorothiazide use and risk of keratinocyte carcinoma and melanoma: A multisite population-based cohort study,” published in the April 2023 issue of Dermatology by Azoulay, et al.
For a study, researchers sought to investigate the potential association between hydrochlorothiazide (HCTZ) and skin cancer, specifically keratinocyte carcinoma and melanoma, in comparison to angiotensin-converting enzyme inhibitors (ACE inhibitors) and calcium channel blockers (CCBs).
Using data from 6 Canadian databases, two new-user, active comparator cohorts were established. Standardized morbidity ratio weighted Cox proportional hazard models were employed to estimate site-specific hazard ratios (HRs) with 95% CIs. Random-effects meta-analysis was used to pool the results.
Overall, HCTZ was not associated with an increased risk of keratinocyte carcinoma compared to ACE inhibitors or CCBs. However, longer durations of HCTZ use (≥10 years) and higher cumulative doses (≥100,000 mg) were linked to increased risks (HR: 1.12; 95% CI: 1.03-1.21 and HR: 1.49; 95% CI: 1.27-1.76, respectively). Regarding melanoma, there was no significant association with ACE inhibitors, but a 32% increased risk was observed with CCBs (crude incidence rates: 64.2 vs. 58.4 per 100,000 person-years; HR: 1.32; 95% CI: 1.19-1.46). The estimated number needed to harm at 5 years of follow-up was 1,627 patients. Similar to keratinocyte carcinoma, increased risks for melanoma were associated with longer durations of use and higher cumulative doses.
The study findings suggested that there may be increased risks of keratinocyte carcinoma and melanoma with longer durations of HCTZ use and higher cumulative doses. Further research is needed to understand these associations and potential confounding factors better.