Abstract 4901: p53 expression is a useful predictive marker for recurrence of meningioma
Authors: Nagahama Atsufumi , Yashiro Masakazu , Miki Yuichiro , Morisako Hiroki , Uda Takehiro , Goto Takeo , Takami Takehiro , Ohata Kenji 
Published: August 2019

Abstract
Introduction: Meningiomas are common intracranial tumor originate from arachnoid cap cells. Meningiomas are classified into three grades (grade I, II, and III) according to World Health Organization (WHO) 2016 criteria. Meningiomas are generally benign tumors with slow growing, and most of them can be treated by one-time resection. However, some of them regrow rapidly and invade into the dura mater widely, which often require additional treatments such as re-operation and irradiation. No useful marker was found to predict the recurrence of meningioma, so far. Then, the aim of this study is to investigate the immunohistochemical (IHC) expression of p53 and to determine the association of this results with the factors which related to the retreatment.
Materials and methods: This retrospective study included 389 patients with intracranial or intraspinal meningiomas which were surgically operated at Osaka City University from 2007 to 2017. The clinicopathological data of each patient was from medical records of Osaka City University hospital. IHC staining of p53 was performed on 389 meningiomas, as follows. The paraffin-embedded sections were de-paraffinized and heated for 10 min at 105°C by autoclave in Target Retrieval Solution. Then sections were incubated with 3% hydrogen peroxide to block endogenous peroxidase activity. The specimens were then incubated with anti-p53 (DO-7) for 1 h at room temperature. The slides were treated with streptavidin-peroxidase reagent and incubated in PBS with 1% (vol/vol) hydrogen peroxide, followed by counterstaining with Mayer's hematoxylin. p53 staining is considered negative when no cell with brown nuclear staining exist. The SPSS software program (SPSS Japan, Tokyo, Japan) was used for the analyses. In all tests, a p-value of less than 0.05 was defined as being statistically significant.
Results: Of the 389 meningiomas, 77cases (19.8%) were p53 positive. Univariate analysis revealed that recurrence of meningioma was significantly correlated with p53 positive (p=0.025), young age (p&lt;0.001), large dural attachment (p&lt;0.001), low height dural attachment ratio (p=0.016), large max diameter (p=0.020) and high Ki-67 index (p&lt;0.001). Multivariate analysis indicated that p53 positive (p=0.037), young age (p=0.002), large dural attachment (p=0.002), low height dural attachment ratio (p=0.046), large max diameter (p=0.001) and high Ki-67 index (p&lt;0.001) were significantly associated with recurrence of meningioma.
Conclusion: p53 expression was correlate with the proliferative activity of meningiomas. p53 might be a useful independent predictive marker for recurrence of meningioma.
Citation Format: Atsufumi Nagahama, Masakazu Yashiro, Yuichiro Miki, Hiroki Morisako, Takehiro Uda, Takeo Goto, Takehiro Takami, Kenji Ohata. p53 expression is a useful predictive marker for recurrence of meningioma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4901.