The importance of considering competing risks in recurrence analysis of intracranial meningioma
Authors: Mirian Christian , Jensen Lasse Rehné , Juratli Tareq A. , Maier Andrea Daniela , Torp Sverre H. , Shih Helen A. , Morshed Ramin A. , Young Jacob S. , Magill Stephen T. , Bertero Luca , Stummer Walter , Spille Dorothee Cäcilia , Brokinkel Benjamin , Oya Soichi , Miyawaki Satoru , Saito Nobuhito , Proescholdt Martin , Kuroi Yasuhiro , Gousias Konstantinos , Simon Matthias , Moliterno Jennifer , Prat-Acin Ricardo , Goutagny Stéphane , Prabhu Vikram C. , Tsiang John T. , Wach Johannes , Güresir Erdem , Yamamoto Junkoh , Kim Young Zoon , Lee Joo Ho , Koshy Matthew , Perumal Karthikeyan , Baskaya Mustafa K. , Cannon Donald M. , Shrieve Dennis C. , Suh Chang-Ok , Chang Jong Hee , Kamenova Maria , Straumann Sven , Soleman Jehuda , Eyüpoglu Ilker Y. , Catalan Tony , Lui Austin , Theodosopoulos Philip V. , McDermott Michael W. , Wang Fang , Guo Fuyou , Góes Pedro , de Paiva Neto Manoel Antonio , Jamshidi Aria , Komotar Ricardo , Ivan Michael , Luther Evan , Souhami Luis , Guiot Marie-Christine , Csonka Tamás , Endo Toshiki , Barrett Olivia Claire , Jensen Randy , Gupta Tejpal , Patel Akash J. , Klisch Tiemo J. , Kim Jun Won , Maiuri Francesco , Barresi Valeria , Tabernero María Dolores , Skyrman Simon , Broechner Anders , Bach Mathias Jacobsen , Law Ian , Scheie David , Kristensen Bjarne Winther , Munch Tina Nørgaard , Meling Torstein , Fugleholm Kåre , Blanche Paul , Mathiesen Tiit 
Published: February 2024

Abstract
Background
The risk of recurrence is overestimated by the Kaplan–Meier method when competing events, such as death without recurrence, are present. Such overestimation can be avoided by using the Aalen-Johansen method, which is a direct extension of Kaplan–Meier that accounts for competing events. Meningiomas commonly occur in older individuals and have slow-growing properties, thereby warranting competing risk analysis. The extent to which competing events are considered in meningioma literature is unknown, and the consequences of using incorrect methodologies in meningioma recurrence risk analysis have not been investigated.

Methods
We surveyed articles indexed on PubMed since 2020 to assess the usage of competing risk analysis in recent meningioma literature. To compare recurrence risk estimates obtained through Kaplan–Meier and Aalen-Johansen methods, we applied our international database comprising ~ 8,000 patients with a primary meningioma collected from 42 institutions.

Results
Of 513 articles, 169 were eligible for full-text screening. There were 6,537 eligible cases from our PERNS database. The discrepancy between the results obtained by Kaplan–Meier and Aalen-Johansen was negligible among low-grade lesions and younger individuals. The discrepancy increased substantially in the patient groups associated with higher rates of competing events (older patients with high-grade lesions).

Conclusion
The importance of considering competing events in recurrence risk analysis is poorly recognized as only 6% of the studies we surveyed employed Aalen-Johansen analyses. Consequently, most of the previous literature has overestimated the risk of recurrence. The overestimation was negligible for studies involving low-grade lesions in younger individuals; however, overestimation might have been substantial for studies on high-grade lesions.