Hypertension med HCTZ linked to skin cancer risk

Despite its widespread use as a guideline-recommended, first-line agent for the treatment of hypertension, hydrochlorothiazide may contribute to an increased risk of skin cancer, according to the division of dermatology, Mohs Micrographic Surgery Unit, Florida State University, Tallahassee.

The common, long-term use of hydrochlorothiazide (HCTZ) for treatment of hypertension, combined with its known photosensitizing effects, makes it a potential candidate for increasing the risk of squamous cell carcinoma (SCC) and other skin cancers.

To further elucidate the association between long-term HCTZ exposure and skin cancer risk, screened medication lists of 75 patients seen in their Mohs practice over a period of five days for lifetime SCCs and HVTZ exposure.

For this study, patients with more than 20 lifetime SCCs were considered high risk. They also conducted a literature review of previous studies exploring this relationship, from 1966 to 2015.

Of the 75 patients screened, four met the criteria for inclusion in the high-risk category. These four patients had a combined lifetime total of 288 SCC and 98 basal cell carcinomas (BCGs), including 10 that were non -Hispanic white males and had been taking HCTZ alone or in combination for 3 -15 years.

The literature search produced three relevant studies, all of which had large patients populations, published between 2008 and 2012, “demonstrating an increased risk of SCC or lip cancer” associated with HCTZ use, with over five years of use, the researchers wrote.

As cutaneous oncologists, it is our duty to look for ‘correctable’ causes of skin cancer. Hydrochlorothiazide, a known photo sensitizer, when taken by white non-Hispanic patients with a history of multiple SCC skin cancers may represent a ‘correctable’ cause.

In their practice, they screen their high-risk SCC non- Hispanic patients for HCTZ use, and send a standard letter explaining the association to the primary care provider with a request to change to a different antihypertensive if possible.

Many primary care providers were unaware of the association between HCTZ use and skin cancer.