Estrogen hormone replacement therapy in incidental intracranial meningioma: a growth-rate analysis.

Incidental meningiomas (IMs) are the most common intracranial neoplasms, especially in perimenopausal women. There is ongoing debate on whether their incidence is increased by hormone replacement therapy. Meningiomas often express estrogen receptors, which were linked to higher proliferative activity according to some reports. Consequently, there is a theoretical risk of estrogen-based HRT (e-HRT) leading to an increase in tumor growth and thus altering the natural history of IMs. However, clinical data is lacking to support this notion. To identify differences in the natural history of IM after e-HRT exposure. We queried the NorthShore Meningioma Database for patients with ≥ 6 months of e-HRT. They were compared with age-matched IM controls. Forty patients were included in the e-HRT group (mean age 62.1 ± 12.0 years; mean duration of HRT 5.3 ± 4.5 years) and 80 in the no-HRT group (mean age 62.2 ± 12 years). Radiographic appearance was similar between groups. The average 2D tumor diameter was 35% lower in the e-HRT group (p = 0.02), with an absolute growth-rate of half of the no-HRT group (p = 0.02). Radiographic and clinical progression-free survival were 1.2 years and 3.3 years longer in the e-HRT group, respectively. These preliminary results suggest that e-HRT may be safe in incidental meningiomas.

Progesterone and allopregnanolone improves stroke outcome in male mice via distinct mechanisms but neither promotes neurogenesis.

Based on the outcome of a number of experimental studies, progesterone (PROG) holds promise as a new therapy for stroke. To understand more about the mechanisms involved, we administered PROG (or the major metabolite, allopregnanolone, ALLO), intra-peritoneally, for a period of 24 h after transient middle cerebral artery occlusion to male mice variably expressing intracellular progesterone receptors (iPR) A/B. Effects on infarct volume and neurogenesis were then assessed up to 1 month later. Predictably, infarct volume in wild-type mice receiving either drug was significantly smaller. However, mice heterozygous for iPRs A/B showed protection by ALLO but not by PROG. There was robust amplification of cell division in the wall of the lateral ventricle on the injured side of the brain, these cells migrated into the striatum and lateral cortex, and a significant number survived for at least 3 weeks. However, very few doublecortin-positive cells emerged from the subventricular zone and subsequent expression of NeuN in these newborn neurons was extremely rare. Neither PROG nor ALLO amplified the rate of neurogenesis, suggesting that the long-term benefits of acute drug administration results from tissue preservation. Male mice derive long-lasting benefit from progesterone and allopregnanolone after ischemic stroke. In mice heterozygous for iPRs, only allopregnanolone proved effective, suggesting distinct mechanisms. Abundant newborn cells were found in the wall of the lateral ventricle on the injured side (many doublecortin-positive), some migrated into the striatum and lateral cortex, but very few survived as mature neurons. Neurosteroid administration did not amplify this process.