He recently earned his PhD in medical science at Lund University and is a senior consultant at the dermatology clinic in Landskrona, Sweden. In one of the studies included in his dissertation, he investigated the links between common blood pressure medications and cases of basal cell carcinoma, a form of skin cancer. This cancer type is very common, with 70,000 newly discovered cases per year in Sweden. It often appears on skin that has been exposed to intense sun.
“Basal cell carcinoma is a rather mild form of cancer, with a low risk of spreading and low mortality. Treatment usually involves surgically removing the tumour, but it’s often also possible to freeze or scrape it away,” says Johan Kappelin.
Previous studies, both Swedish and international, have shown a likely increased risk of various skin cancers in connection with antihypertensive medications. When focusing specifically on basal cell carcinoma, Johan Kappelin used several large Swedish registries to identify possible statistical associations between the disease and blood pressure medication.
There are many different blood pressure medications, grouped by their active substances. These types were included in Johan Kappelin’s study:
- Thiazides (diuretics)
- ACE inhibitors (angiotensin-converting enzyme 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 nine percent. 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 seven percent increased risk. For ACE inhibitors, on the other hand, no increased risk was found; according to these study results, the risk even appeared to decrease slightly.
Johan Kappelin is somewhat surprised that such similar risk increases were seen across several medication types.
“It’s also 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?” he wonders.
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 Johan Kappelin.
