After coming across several papers, it appears cyproterone acetate (Androcur) is strongly linked to the occurrence of meningiomas in transsexual women (all 4 cases included cyproterone acetate), in addition to ciswomen and men.
Acta Neurochir (Wien). 2010 Nov;152(11):1955-6.
"The important regression in our case confirms a strong influence of cyproterone acetate on meningiomas growth."
"In case of meningioma in a patient treated with cyproterone acetate and without significant symptoms, a conservative strategy, including discontinuation of cyproterone acetate, should be considered. Furthermore, because higher dose of cyproterone acetate are commonly used for the male-tofemale transsexual patient, clinician caring for those patient should be aware of such event that could be more frequent in the transsexual population."
AJNR Am J Neuroradiol. 2010 Sep;31( 8 ):1504-5.
"Recent observations of meningioma, often multiple, among users of high doses of cyproterone acetate have raised the suspicion that it may promote the rapid growth of pre-existing or new meningioma.1 Here, we report the rapid regression of a meningioma after discontinuation of a 10-year cyproterone acetate treatment. This unique observation strengthens the link between cyproterone acetate and intracranial meningioma"
"The suspicion that high daily doses of cyproterone acetate for long periods could be responsible for the development of meningiomas, and especially multiple meningiomas, was reported in 2008.1 Froelich et al1 reported multiple meningiomas in 9 female patients treated with cyproterone acetate. Before treatment withdrawal, an increase in tumor size and/or the development of new meningiomas was observed in all 6 patients with available imaging follow-up. Treatment withdrawal was associated with lesion size/number stabilization. »
« Our observation of rapid meningioma regression after hormonal treatment discontinuation reinforces the link between meningioma and cyproterone acetate. We cannot formally exclude the possibility that estradiol discontinuation may have played a role in the lesion regression. Any such role is likely to have been minor, given that the patient was taking a low dose of substitutive estrogen therapy to counterbalance the antiestrogenic effect of cyproterone. Furthermore, estrogen receptors are often minimally present or absent in meningioma."
"Taken together, the multiplicity of meningiomas and rapid lesion growth in patients treated with cyproterone acetate and, as shown here, the rapid lesion regression following treatment withdrawal suggest that this treatment may actively stimulate, and its withdrawal inhibit, the meningioma cell cycle. The link between meningioma and cyproterone acetate may be stronger than that with other progestative therapies."
Endocrinol Nutr. 2013 May;60(5):264-7.
« We report a case of a meningioma in a male-to-female transsexual patient treated with estrogens and cyproterone acetate for the past 4 years. He claimed recently severe headache and visual impairment. Blood tests showed normal results. A contrast-enhanced magnetic resonance imaging (MRI) scan revealed a mass in the tuberculum sellae consistent with a meningioma. Treatment was discontinued and tumor resection was performed. Histologic diagnosis confirmed strongly progesterone receptor-positive and estrogen negative meningioma. After surgery, the patient rejected the possibility of continuing with the treatment of estrogens and cyproterone, and so triptorelin (GnRH agonist) was initiated. At 1-year follow-up the patient's symptoms had ameliorated and a MRI scan revealed no recurrence of the tumor. This is the third case reported in the literature of a meningioma after treatment with estrogens and cyproterone acetate."
SOJ Neurology 01/2014; 1(2)
"A 56-year-old male-to-female transsexual patient reported progressive severe left parietal headache during the previous 1.5 years. The neurological exam detected no abnormalities, but a review of clinical history revealed that the patient had been treated with Progynova (...) for 8 years as well as cyproterone acetate, an anti-androgenic drug with semiprogesterone effects."
"The patient had been taking a feminizing endocrine regimen of ethinyl estradiol (...) and cyproterone acetate (...) for the previous 5 years. After 2 years of hormone treatment, the patient underwent gonadectomy for sex reassignment, and estradiol-17-undecanoate (...) was added to the patient's therapy for the following 2 years. A cerebral magnetic resonance imaging (MRI) scan obtained 3 years before presentation to evaluate an increased prolactin level (42 ng per milliliter) was negative (Fig. 1A). On admission, a contrastenhanced MRI scan revealed a giant olfactorygroove meningioma (Fig. 1B). After a radical tumor resection, the histologic diagnosis was meningothelial meningioma"
"At 1 year of follow-up, the patient was continuing with the hormone therapy at a lower dose (... ethinyl estradiol per day and ... of spironolactone per day), and a contrast-enhanced MRI scan showed no recurrence of the tumor. The patient's behavioral changes had regressed, and the visual impairments were ameliorated."
"In this case, a causal association between the growth of a meningioma and the hormone therapy was suggested by the negative cerebral MRI scan obtained 3 years before presentation."
Acta Neurochir (Wien). 2015 Oct;157(10):1741-6.
"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"
"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)."
"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."
Neurochirurgie. 2015 Oct;61(5):339-42.
"We report two cases illustrating multiple meningiomas with stabilization or tumor reduction after withdrawal of cyproterone acetate originally prescribed for a long term period."
Cancer Epidemiol. 2012 Apr;36(2):198-205.
"In total, 745 patients with meningioma were identified from a study population of 2171287. No significantly increased risk of meningiomawas found among female users of oral contraceptives (OR: 1.15; CI: 0.67-1.98), hormone replacement therapy (OR: 0.99; CI: 0.73-1.35) or low-dosecyproterone acetate (CPA; OR: 1.51; CI: 0.33-6.86) compared with non-users. There was a significantly increased risk of meningioma among male users of androgen analogues (OR: 19.09; CI: 2.81-129.74) and among users of high-dose CPA (OR: 6.30; CI: 1.37-28.94) compared with non-users, however there were only three cases currently using these drugs."
Br J Clin Pharmacol. 2011 Dec;72(6):965-8.
"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."
"The results of this study support the hypothesis that the exposure to high dose CPA increases the risk of meningioma."
Cyproterone acetate has also been implicated in the majority of prolactinoma cases observed in transsexual women.
Other side-effects sometimes associated with this drug: depression, irritability, extreme fatigue (due to Vitamin B12 depletion). May adversely affect coagulation, slightly increasing risk of clots. High doses have the potential to cause hepatotoxicity, more so long-term. Studies and anecdotes to support this.
If I had known what I know now, I would have never personally agreed to take this anti-androgen. As always, I'm not a doctor, just sharing findings with you so you are more aware. You can discuss these with your doctor and see what they have to say.
But to be fair and objective, some of these side-effects seem most likely with higher doses and when taken long-term so if used for a short-time at lower dosages, risks should be significantly reduced.
