Some blood pressure medications can increase risk of basal cell carcinoma, a new study in Acta Dermato Venereologica suggests.
“Blood pressure treatment should not be discontinued. But it’s good if doctors inform patients that extra sun protection may be needed,” says researcher Johan Kappelin, PhD, a senior consultant at the dermatology clinic in Landskrona, Sweden.
In one of the studies included in his dissertation, Kappelin investigated the links between common blood pressure medications and cases of basal cell carcinoma. When focusing specifically on basal cell carcinoma, he used several large Swedish registries to identify possible statistical associations between the disease and blood pressure medication.
The types of blood pressure medication included in the study were:
- Thiazides (diuretics)
- Angiotensin-converting enzyme inhibitors (ACE inhibitors)
- Angiotensin II receptor blockers (ARBs)
- Calcium channel blockers
- Beta blockers
Among those who used thiazides, ARBs, and calcium channel blockers, the risk of basal cell carcinoma appeared to increase by 9%. For the thiazide group, however, this only applied to medications containing multiple active substances (so-called combination therapy). For beta blockers, the results showed a 7% increased risk. For ACE inhibitors, no increased risk was found; according to these study results, the risk even appeared to decrease slightly.
“It’s … a bit surprising that medications containing only thiazides as the active substance did not appear to increase the risk of basal cell carcinoma. At the same time, an increased occurrence of basal cell carcinoma was seen in people who received thiazides as combination therapy. Is the risk found in the other agent, or is it the combination itself that creates the risk?” Kappelin asks.
Other questions requiring further research include whether factors such as skin type and/or certain lifestyle factors contribute to the risk of basal cell carcinoma during blood pressure treatment.
“The increase in basal cell carcinoma risk with these medications is quite small in our study, and at present we see no reason to change any recommendations regarding the use of these drugs. However, there may be reason to be extra careful with sun protection when undergoing blood pressure treatment,” recommends Kappelin.
To determine possible statistical associations, researchers compared people with basal cell carcinoma to people without such a diagnosed disease.
The approximately 130,000 patient cases came from the national Basal Cell Carcinoma Registry. The control group consisted of roughly twice as many individuals, drawn from the Swedish Population Register. Data on prescriptions for antihypertensive medications came from the Prescribed Drug Register. Researchers also collected registry data on other ongoing medications and other diseases among the included individuals.
Many other factors were not examined in the study, such as skin type or lifestyle factors. Therefore, the researchers emphasize, it cannot be definitively determined that it is the blood pressure medications that cause the increased risk of basal cell carcinoma.
