Use of antiepileptic drugs and risk of skin cancer: A nationwide case-control study

Abstract

Background: Several antiepileptic drugs are photosensitizing; however, it is not known whether this confers an increased risk of skin cancer.

Objective: To examine the association between common antiepileptic drugs and basal cell carcinoma, squamous cell carcinoma (SCC), and malignant melanoma.

Methods: We conducted a nested case-control study identifying skin cancer patients in Denmark from 2004 through 2015 matched 1:10 with disease-free controls. We estimated odds ratios (ORs) for skin cancer associated with high cumulative use of antiepileptic drugs (≥500 defined daily doses) compared with nonuse.

Results: Most antiepileptic drugs were not associated with skin cancer. SCC was associated with use of carbamazepine (OR, 1.88; 95% confidence interval, 1.42-2.49) and lamotrigine (OR, 1.57; 95% confidence interval, 1.12-2.22) with evidence of a dose-response relationship for carbamazepine. The estimated absolute risks were low; for example, 6335 person-years of high cumulative exposure to carbamazepine were required for 1 additional SCC to occur.

Limitations: Data on important risk factors for skin cancer, such as sun exposure, were not available.

Conclusions: Most antiepileptic drugs were not associated with skin cancer; however, carbamazepine and lamotrigine were associated with SCC. These findings need to be replicated and characterized further in other settings and have no direct clinical implications.

Keywords: adverse effects; antiepileptic drugs; cancer risk; epidemiology; malignant melanoma; nonmelanoma skin cancer; pharmacology; skin cancer.