Open Access

Felix Behling, C. Fodi, J. Honegger, G. Tabatabai, M. Tatagiba, J. Schittenhelm

• Background: The prognostic assessment in meningiomas is of high importance to detect patients at risk of recurrence as early as possible. Recently, an integrative molecular classification of meningiomas with prognostic impact has been described. There is first evidence that S100 may be a marker associated with a favorable clinical course. Methods: We therefore assessed the immunohistochemical expression of S100 in our meningioma cohort of 1664 paraffin-embedded and formalin-fixated tumor tissue samples. A semi-quantitative scoring system was applied. Correlations with clinical parameters were done (gender, age, NF2, prior radiotherapy, histological subtype, WHO grade, proliferation activity and time to tumor recurrence). Results: A strong expression of S100 was seen in 195 meningiomas (11.7%). A higher rate of cases with high expression was seen with female gender (p= 0.0004), NF2 (p< 0.0001), spinal and convexity/falx location (p< 0.0001) and WHO grade I (p= 0.0073). Kaplan-MeierBackground: The prognostic assessment in meningiomas is of high importance to detect patients at risk of recurrence as early as possible. Recently, an integrative molecular classification of meningiomas with prognostic impact has been described. There is first evidence that S100 may be a marker associated with a favorable clinical course. Methods: We therefore assessed the immunohistochemical expression of S100 in our meningioma cohort of 1664 paraffin-embedded and formalin-fixated tumor tissue samples. A semi-quantitative scoring system was applied. Correlations with clinical parameters were done (gender, age, NF2, prior radiotherapy, histological subtype, WHO grade, proliferation activity and time to tumor recurrence). Results: A strong expression of S100 was seen in 195 meningiomas (11.7%). A higher rate of cases with high expression was seen with female gender (p= 0.0004), NF2 (p< 0.0001), spinal and convexity/falx location (p< 0.0001) and WHO grade I (p= 0.0073). Kaplan-Meier Analysis showed a favorable disease course for meningiomas showing a strong expression of S100 (p= 0.0099) but multivariate analysis did not confirm a prognostic effect for S100. Conclusions: Strong immunohistochemical expression of S100 is associated with benign meningiomas but is not an independent prognostic marker.…