An audit of immunohistochemical marker patterns in meningioma

Meningiomas may express a number of potentially growth-promoting receptors including receptors for progesterone, growth hormone and vascular endothelial growth factor (VEGF). These and other receptors are potential targets for chemotherapy. We have prospectively studied a panel of markers as a routine in order to obtain data of individual expression of markers that may provide targets for anti-receptor treatment. One hundred and seventy-five consecutive patients operated on for meningiomas between 2005 and 2008 were prospectively analysed with antibodies against receptors for growth hormone, insulin-like growth factor 1 (IGF-1), androgen receptors, progesterone receptors (PR) and antibodies against CD34, VEGF, Ki-67 and caspase-3. Expression of IGF-1 receptor (IGF-1r), epidermal growth factor receptor (EGFR) E30 and growth hormone receptor (GHr) was conserved across histological grades and found in 88% to 94% of meningiomas. PR were detected in 87%, but expression decreased in aggressive tumours. Angio-markers such as VEGF and CD34 were detected in 69% and 17% of meningiomas, respectively. Androgen receptors and caspase-3 were uncommon. The analyses of a panel were undertaken as a clinical routine in order to assess its feasibility and to provide data that can be utilised in a clinical setting. Three putative therapeutic receptor targets, IGF-1r, GHr and EGFR E30 were expressed in a large majority of tumours and in contrast to PR maintained expression despite increasing pathological grade of meningioma. Our data also suggest that anti-progesterone therapies and anti-angiogenic therapies could be targeted to subsets of meningioma patients who express PR or have CD34-positive tumours.