Hormone treatment of meningiomas: lack of response to medroxyprogesterone acetate (MPA). A pilot study of five cases.

Medroxyprogesterone acetate (MPA) has been used in high doses as hormone treatment for metastatic breast cancer. We treated five intracranial meningiomas with MPA expecting that MPA would reduce the volume or decrease the growth rate. All five patients were postmenopausal women, aged 47 to 73 years. Before treatment, the growth rate of each tumour was assessed by two consecutive CT scans (CT 1 and CT 2). Tumours 1 to 4, histologically benign meningiomas, grew slowly as the tumour volumes were not found to increase in 21 to 45 months between CT 1 and CT 2. Tumour 5 was an anaplastic meningioma the rapid growth of which was evident in 8 weeks between CT 1 and CT 2. After CT 2, MPA was given 1,000 mg intramusculary once weekly for 17 to 29 weeks until CT 3 which showed the response. Tumours 1 to 4 had neither reduced in volume nor developed necroses, and tumour 5 continued its fast growth at the same rate as before.