Quantitative imaging of
estrogen receptors (ER's),
progesterone receptors (PR's),
estrogen-regulated protein (pS2), and growth fraction (Ki67) immunocytochemical assays were performed in 52
meningiomas. The results were correlated with clinical (age, sex, hormonal status, and
tumor volume and location) and morphological (histological types and grades) data. The authors observed a lack of ER's in all
meningiomas but the presence of PR's in 53% of these
meningiomas. The immunoreactivity was restricted to
tumor cell nuclei. The PR immunocytochemical assay was correlated with
tumor location, histological type, histological grade, and pS2 immunocytochemical assay, but not with Ki67 immunocytochemical assay; high PR content was observed in cisternae, transitional, meningothelial, and low-grade
meningiomas. Only 11
meningiomas showed more than 1% Ki67 immunoreactive nuclei. These
meningiomas were usually located in the convexity and were of high histological grade.
Estrogen-regulated protein immunoreactivity was observed in 34
meningiomas but the number of immunoreactive nuclei was low. The pS2 immunocytochemical assay was not related to clinicopathological features but was preferentially observed in PR-negative
meningiomas. The results of this study are compared with those previously reported, and the function and regulation of PR's in
meningiomas is discussed. The results indicate that 1) regulation of PR's and pS2
proteins in
meningiomas differs from regulation in
estrogen-dependent tissues such as breast or endometrium; 2) interruption of hormonal
therapy in women presenting with a
meningioma is not absolutely necessary; 3)
meningiomas have different
biological properties according to their clinicopathological features; and 4) future studies of hormonal clinical trials should be performed on well-defined
meningioma subgroups.