Risk of meningioma among users of high doses of cyproterone acetate as compared with the general population: evidence from a population-based cohort study.

WHAT IS ALREADY KNOWN ON THIS SUBJECT • Information from the spontaneous reporting system raised the hypothesis of an increased risk of meningioma in patients treated with high doses of cyproterone acetate (CPA). • Meningiomas are known to be hormone-sensitive tumours and express progesterone receptors and CPA has an anti-androgenic, progestagenic and antigonadotropic effect. • More formal evidence from epidemiological studies is lacking. WHAT THIS STUDY ADDS • This population-based cohort study supports the hypothesis that the exposure to high dose CPA increases the risk of meningioma • The increased risk was observed both in men and women and was only relevant for exposures longer than 1 year. AIM Information from the spontaneous reporting system raised the hypothesis of an increased risk of meningioma in patients treated with high doses of cyproterone acetate (CPA). The objective of this study was to test the hypothesis of an increased risk of meningioma among users of high dose CPA as compared with non-users in a medical records computerized database. METHODS A retrospective cohort study was performed in a Spanish primary care database (BIFAP). Meningioma incidence rates were compared in patients exposed to high dose CPA (users) with those non-exposed and with those exposed to low dose CPA. Poisson regression analysis was used to estimate the incidence rate ratios after adjusting for age and gender. RESULTS Among 2474 users of high dose cyproterone (6663 person-years) four meningioma cases were identified, resulting in an incidence rate (IR) of 60.0 (95% CI 16.4, 153.7) per 100 000 person-years, which was significantly higher than that observed among the non-users (IR 6.6; 95% CI 6.0, 7.3) and among women users of low dose cyproterone (IR 0.0, 95% CI upper limit 5.5). After adjusting for age and gender, patients exposed to high dose CPA showed an increased risk of meningioma of 11.4 (95% CI 4.3, 30.8) as compared with non-users. CONCLUSIONS The results of this study support the hypothesis that the exposure to high dose CPA increases the risk of meningioma.