BAG-1 expression in human meningioma and correlation with clinical characteristics

The aim of this study is to investigate BAG-1 expression in human meningiomas and to assess its association with pathological and clinical characteristics. BAG-1 expression was analyzed in 158 specimens of meningiomas using immunohistochemical staining, and the results were graded according to the positivity ratio and the staining intensity. We examined the correlations between BAG-1 expression and the 2007 WHO pathological classification, peritumoral edema and postoperative recurrence. There were no significant differences in BAG-1 expression among meningioma subtypes within the same histopathologic grade, as well as between grades II and III. BAG-1 expression in grade I was much higher than in grade II (P < 0.05) or III (P < 0.01). BAG-1 expression was gradually decreased with increasing WHO pathologic classification (χ 2 = 141.49, P < 0.01), as well as with the increase in peritumoral edema (χ 2 = 43.93, P < 0.01) and postoperative recurrence (χ 2 = 55.13, P < 0.01). BAG-1 expression in meningioma depends upon WHO pathologic classification and is decreased in higher tumor classification. It is associated with heavier peritumoral edema and more postoperative recurrences.