Background: The relationship between meningiomas and exogenous sex hormones is well known, but cyproterone acetate (CA), a progesterone agonist, seems to have a stronger influence on tumor growth.
Objective: To show the close relationship between CA treatment and meningioma growth.
Methods: Since 2010, all patients referred to our clinic for a suspicion of meningioma were questioned specifically about exogenous sex hormone intake and more specifically about CA intake. Twelve patients harboring one or multiple meningiomas and treated with CA were identified. CA was stopped in all cases. Tumor volumes and diameters were measured on serial MRIs and compared to the last MRI before CA withdrawal.
Results: Ten patients with multiple tumors had been taking the drug for a longer period of time (mean of 20.4 years) than the two patients with one tumor (10 years). Two patients with multiple tumors underwent surgery because of rapidly decreased visual acuity at the time of diagnosis. Discontinuation of CA led to tumor shrinkage in 11 patients and a stop in tumor growth in one [mean tumor volume reduction was around 10 cm(3)/year; range (0.00; 76)]. There was no regrowth during a mean follow-up period of 12 months (range: 5-35).
Conclusion: For patients diagnosed with a meningioma and treated with CA, medication withdrawal followed by observation should be the first line of treatment. Care should be taken with long-term use of high doses of CA, and serial brain MRIs should be considered after several years of CA.
Keywords: Cyproterone acetate; Meningioma; Meningiomatosis; Progesterone agonist.