Clinicopathological variables, immunophenotype, chromosome 1p36 loss and tumour recurrence of 247 meningiomas grade I and II.

The WHO grading scheme distinguishes benign (grade I), atypical (grade II) and anaplastic (grade III) meningiomas. Both atypical and anaplastic meningiomas exhibited an overall increased rate of recurrence, but between 15-20% benign meningiomas will also exhibit an unfavourable clinical course with recurrence before 10 years despite aggressive surgery. We investigated 247 cases of meningiomas grade I and II. The immunohistochemical expression of 30 different molecular biomarkers of cell adhesion molecules, cell-cycle and apoptosis regulators and checkpoints was analyzed. We also determined apoptosis by in-situ hybridization (APOPDETEKTM) and loss of chromosome 1p36 by FISH. The study revealed a statistically significant co-variation (p<0.05) between meningiomas grade II associated with several clinicopathological features (Simpson grade of clinical resection, necrosis, nuclear atypia, macronucleoli, transition to small cell, sheet-like growth, high cellularity), increased expression of several biomarkers of tumour proliferation (Cyclin A, Cyclin E, MIB-1 or MDM2), proteases (Cathepsin D) or cell-adhesion (CD44) and lower expression of progesterone receptors than meningiomas grade I. The presence of Psammoma bodies or the location at convexity were protective prognostic factors for tumour recurrence while high cellularity and early age of onset (<57 year-old) were indicators of increased recurrence risk. The expression of COX-2, gamma-catenin, Topoisomerase IIa, VEGF and MIB-1 was significantly higher in the cohort of recurrent meningiomas. Meningiomas with chromosome 1p36 loss showed a higher recurrence rate (33.3%) than meningiomas with normal chromosome 1p36 (18%). Increased COX-2 expression in recurrent meningioma may also suggest a putative role of COX-2 inhibitors as a chemopreventive treatment for recurrence.