Meningiomas in patients with long-term exposition to progestins: Characteristics and outcome

The aim of this study was to describe progestin-associated meningiomas' characteristics, outcome and management.

We included 53 patients operated on and/or followed in the department for meningioma with progestin intake longer than one year and with recent drug discontinuation.

Cyproterone acetate (CPA), nomegestrol acetate (NomA), and chlormadinone acetate (ChlA) were involved in most cases. Mean duration of progestin drugs intake was 17.5 years. Tumors were multiple in 66% of cases and were located in the anterior and the medial skull base in 71% of cases. Transitional subtype represented 16/25 tumors; 19 meningiomas were WHO grade I and 6 were grade II. The rate of transitional subtype and skull base location was significantly higher compared to matched operated meningioma general population. No difference was observed given WHO classification. But Ki67 proliferation index tends to be lower and 5/6 of the WHO grade II meningiomas were classified as WHO grade II because of brain invasion. Strong progesterone receptors expression was observed in most cases. After progestin discontinuation, a spontaneous visual recovery was observed in 6/10 patients. Under CPA (n=24) and ChlA/NomA (n=11), tumor volume decreased in 71% and 18% of patients, was stabilized in 25% and 64% of patients, and increased in 4% and 18% of patients, respectively. Volume outcome was related to meningioma location.

Outcome at progestins discontinuation is favorable but different comparing CPA versus ChlA-NomA and comparing tumor location. Long-term follow-up is required. In most cases, simple observation is recommended and surgery should be avoided.