Study finds no link between epilepsy and cancer

Authors of a recent study say their data does not confirm previous observations of an association between epilepsy and the risk of some types of cancer.The Swedish authors say that although there have been suggestions that epilepsy and the long-term use of antiepileptic drugs are associated with an increased risk of cancer, the issue has received little attention and the few studies that have examined the issue have been conflicting. To examine whether epilepsy is a risk factor for particular non-CNS malignancies, the authors conducted a case-control study using data from the Swedish Cancer Registry from 1987 to 1999. They identified all cases (n = 52,861) of leukaemia, lymphoma, myeloma, and pancreatic cancer over the review period and randomly selected controls (n = 137,485) from the Swedish Population Registry. All cases and controls with first-time hospital discharge for epilepsy between 1969 and 1999 were identified via the Swedish Hospital Discharge Registry records. The data showed that a diagnosis of epilepsy the same year as a diagnosis of cancer carried an increased risk for leukaemia, pancreatic cancer, non-Hodgkin's lymphoma and Hodgkin's disease. However, there was no increased risk of cancer in patients who had been diagnosed with epilepsy two years before the cancer diagnosis. Similarly there was no association between cancer and epilepsy in individuals who had received an epilepsy diagnosis more than ten years before being diagnosed with one of the forms of cancer.The authors suggest that the increased risk of cancer diagnosis in the same year as epilepsy diagnosis is probably due to clinical examinations prompted by the seizures. They add, "...these results lend no support to the suggestion that epilepsy, and presumably long term exposure to antiepileptic drugs, is associated with an increased risk of the types of cancer included in the present study."Reference...