Anti-seizure medication is not associated with an increased risk to develop cancer in epilepsy patients

OBJECTIVE: Whether anti-seizure medication (ASM) increases the risk for cancer has been debated for decades. While for some ASM, a carcinoma-promoting effect has been suspected, carcinoma-protective effects have been shown for other ASM. However, the issue remains unresolved as data from preclinical and clinical studies have been inconsistent and contradictory. METHODS: We collected anonymous patient data from practice neurologists throughout Germany between 2009 and 2018 using the IMS Disease Analyzer database (QuintilesIMS, Frankfurt, Germany). People with epilepsy (PWE) with an initial cancer diagnosis and antiepileptic therapy prior to the index date were 1:1 matched with a control group of PWE without cancer according to age, gender, index year, Charlson Comorbidity Index, and treating physician. For both groups, the risk to develop cancer under treatment with different ASMs was analyzed using three different models (ever use vs. never use (I), effect per one (II) and per five therapy years (III). RESULTS: A total of 3152 PWE were included (each group, n = 1,576; age = 67.3 ± 14.0 years). The risk to develop cancer was not significantly elevated for any ASM. Carbamazepine was associated with a decreased cancer risk (OR Model I: 0.699, p < .0001, OR Model II: 0.952, p = .4878, OR Model III: 0.758, p < .0004). SIGNIFICANCE: Our findings suggest that ASM use does not increase the risk of cancer in epilepsy patients. SUPPLEMENTARY INFORMATION: The online version of this article (10.1007/s00415-020-10379-4) contains supplementary material, which is available to authorized users.