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

Abstract

Several antiepileptic drugs are photosensitizing; however, it is not known whether this confers an increased risk of skin cancer. To examine the association between common antiepileptic drugs and basal cell carcinoma, squamous cell carcinoma (SCC), and malignant melanoma. 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. 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. Data on important risk factors for skin cancer, such as sun exposure, were not available. 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.