Christian Mirian, Lasse Rehné Jensen, Adam Gorm Hoffmann, Andrea Daniela Maier, Tareq A Juratli, Sverre H Torp, Helen A Shih, Ramin A Morshed, Jacob S Young, Stephen T Magill, Luca Bertero, Walter Stummer, Dorothee Cäcilia Spille, Benjamin Brokinkel, Soichi Oya, Satoru Miyawaki, Nobuhito Saito, Martin Proescholdt, Yasuhiro Kuroi, Konstantinos Gousias, Matthias Simon, Jennifer Moliterno, Ricardo Prat-Acin, Stéphane Goutagny, Vikram C Prabhu, John T Tsiang, Johannes Wach, Erdem Güresir, Junkoh Yamamoto, Young Zoon Kim, Joo Ho Lee, Daniel W Kim, Matthew Koshy, Karthikeyan Perumal, Mustafa K Baskaya, Donald M Cannon, Dennis C Shrieve, Chang-Ok Suh, Jong Hee Chang, Maria Kamenova, Sven Straumann, Jehuda Soleman, Ilker Y Eyüpoglu, Tony Catalan, Austin Lui, Philip V Theodosopoulos, Michael W McDermott, Pedro Góes, Manoel Antonio de Paiva Neto, Ricardo Komotar, Michael E Ivan, Aria Jamshidi, Evan Luther, Luis Souhami, Marie-Christine Guiot, Tamás Csonka, Toshiki Endo, Olivia Claire Barrett, Randy Jensen, Tejpal Gupta, Akash J Patel, Tiemo J Klisch, Jun Won Kim, Francesco Maiuri, Valeria Barresi, María Dolores Tabernero, Simon Skyrman, Ian Law, Bjarne Winther Kristensen, Tina Nørgaard Munch, Torstein Meling, Kåre Fugleholm, Paul Blanche, Anders Broechner, Tiit Mathiesen
Simpson grading remained strongly associated with recurrence after GTR. These findings suggest that the extent of dural and bony clearance remains clinically relevant; however, Simpson grading should be contextualized within tumor biology and anatomic constraints. Future recurrence models integrating molecular and surgical variables may refine prognostic frameworks rather than current standalone classification systems.
BACKGROUND AND OBJECTIVES: Simpson grading remains the most widely used clinical classification of extent of resection in meningioma surgery, yet its relevance in modern neurosurgical practice remains debated. The aim was to evaluate whether Simpson grading is associated with recurrence risk after gross total resection (GTR) of intracranial meningiomas within the context of tumor biology and anatomic location.
METHODS: We analyzed 4074 patients undergoing GTR (Simpson grades 1-3) for primary intracranial meningioma, compiling data from 42 institutions worldwide. Cumulative incidence of recurrence was estimated using Aalen-Johansen methods. Multivariable inverse probability of censoring weighted logistic regression models were used to estimate adjusted recurrence risks at 5 and 10 years, adjusting for age, sex, World Health Organization (WHO) grade, Ki-67 proliferation index, and healthcare system setting.
RESULTS: Higher Simpson grades were consistently associated with increased recurrence risk in WHO-1 and WHO-2. Among WHO-1, Simpson grade 2 had more than twice the recurrence odds compared with grade 1 at 5 years, whereas grade 3 showed even higher odds ratio of 3.47 (95% CI, 1.98-6.08). Similar patterns were observed in WHO-2 tumors. Interaction analyses suggested that differences between Simpson grades increase with higher Ki-67 proliferation indices. The prognostic significance of Simpson grade varied across anatomic locations, with clear associations observed for convexity and skull-base meningiomas, but limited relevance for parasagittal/falx meningiomas irrespective of WHO grade.
CONCLUSION: Simpson grading remained strongly associated with recurrence after GTR. These findings suggest that the extent of dural and bony clearance remains clinically relevant; however, Simpson grading should be contextualized within tumor biology and anatomic constraints. Future recurrence models integrating molecular and surgical variables may refine prognostic frameworks rather than current standalone classification systems.