Blood pressure medications may raise BCC risk

A registry study from Lund University in Sweden shows a possible increased risk of basal cell carcinoma with certain blood pressure medications. Because the risk increase is relatively low, 9% or lower, the researchers do not recommend treatment discontinuation. Instead, physicians should inform their patients that extra sun protection may be needed.

The study’s lead author, Johan Kappelin, PhD, is a senior consultant at the dermatology clinic in Landskrona, Sweden.

“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,” said Dr. Kappelin, in a press release from the university.

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, Dr. Kappelin used several large Swedish registries to identify possible statistical associations between the disease and blood pressure medication. The study population included 130,000 patient cases from the Swedish national Basal Cell Carcinoma Registry. The control group included roughly twice as many individuals, drawn from the Swedish Population Register. Data on prescriptions for antihypertensive medications came from the Prescribed Drug Register. The researchers also collected registry data on other ongoing medications and other diseases among the included individuals.

The blood pressure medications included in the recent study were:

• 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 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, on the other hand, Dr. Kappelin and his colleague found no increased risk. The risk even appeared to decrease slightly.

Dr. Kappelin said he 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 said.

Other questions requiring further research include whether factors such as skin type or 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,” Dr. Kappelin said.