A meningioma is a
tumour arising from the meninges covering the brain. They account for 15% of all primary
brain tumours. Although meningiomas are generally benign tumours they may kill the patient
in due time by virtue of their intracranial position and by the pressure they exert on the
brain. Currently,
the accepted management of these tumours is attempted total surgical excision when
technically possible and when associated with an acceptable risk. However, there is a
danger of severe or even total haemorrhage. Epidermological evidence, including the
greater incidence of female patients, a positive association with pregnancy, and a
positive association with breast cancer suggested a role for female sex hormones (and
hormonal regulation) in regulating the growth of meningioma.
Meningioma specimens have more
often been found positive for progesterone receptors than oestrogen receptors. Modulation
of progesterone levels via the progesterone-receptor protein would seem to be a promising
strategy for inhibiting meningioma.
Meningioma specimens have more
often been found positive for progesterone receptors than oestrogen receptors. Modulation
of progesterone levels via the progesterone-receptor protein would seem to be a promising
strategy for inhibiting meningioma growth.
Several trials have now indicated
an inhibitor action of the anti-progestin mifepristone e.g. oral administration of
mifepristone 200mg daily for extended periods to 13 patients with unresectable meningiomas
resulted in minor tumour regression in 5 patients and stabilisation of disease in a
further 5 patients. 11 of the patients on the trial had shown objective or symptomatic
progression before the study.
In another study, mifepristone
200mg daily for 12 months resulted in control of tumour growth in 6 out of 10 patients who
had shown recent neuological and/or opthalmological evidence of tumour growth.
Long term therapy has been well
tolerated. Adverse events include fatigue, hot flushes, gynaecomastia/ breast tenderness,
skin rash, cessation of menses and decrease in libido. Increase in cortisol and TSH
(thyroid-stimulating hormone) are the most striking endocrine changes. |