TY - JOUR
T1 - Mitotic Index and Progression-Free Survival in Atypical Meningiomas
AU - Domingo, Ricardo A.
AU - Tripathi, Shashwat
AU - Vivas-Buitrago, Tito
AU - Lu, Victor M.
AU - Chaichana, Kaisorn L.
AU - Quiñones-Hinojosa, Alfredo
N1 - Publisher Copyright:
© 2020 Elsevier Inc.
PY - 2020/10
Y1 - 2020/10
N2 - Extent of resection and tumor grade are considered the most important predictors of progression-free survival (PFS) in meningiomas. However, adjuvant therapy for atypical meningiomas remains controversial, with variable PFS rates of up to 40%. The current mitotic index (MI) range for atypical meningiomas is broad, comprising all tumors with >4 and <20 mitotic count per 10 high-power fields, leading to substantial within-grade variation of recurrence risk, especially in borderline histologic cases, creating discordance between the clinical course and the application of the classification criteria. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a search of electronic databases from inception to July 2019 identified 121 articles for screening. After proper exclusion criteria, 7 articles were included for data extraction and analysis using meta-analysis of proportions. The MI was the variable of interest in the multivariate regressions and analyzed as a predictor of recurrence using hazard ratios (HRs) (95% confidence intervals). Separate random effect models were used for studies reporting the MI as a continuous or categorical variable. The pooled study results in this meta-analysis demonstrate a homogeneous statistically significant correlation between the MI and the rate of local recurrence after surgical resection regardless of the reporting method (continuous: HR = 1.20; categorical: HR = 2.65). However, significant limitations were noted, including the lack of a standardized method for MI calculation and heterogeneity of MI reports. We encourage the community to report their experience with the MI with greater precision and uniformity to further assess the influence of the MI on PFS within atypical meningiomas.
AB - Extent of resection and tumor grade are considered the most important predictors of progression-free survival (PFS) in meningiomas. However, adjuvant therapy for atypical meningiomas remains controversial, with variable PFS rates of up to 40%. The current mitotic index (MI) range for atypical meningiomas is broad, comprising all tumors with >4 and <20 mitotic count per 10 high-power fields, leading to substantial within-grade variation of recurrence risk, especially in borderline histologic cases, creating discordance between the clinical course and the application of the classification criteria. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a search of electronic databases from inception to July 2019 identified 121 articles for screening. After proper exclusion criteria, 7 articles were included for data extraction and analysis using meta-analysis of proportions. The MI was the variable of interest in the multivariate regressions and analyzed as a predictor of recurrence using hazard ratios (HRs) (95% confidence intervals). Separate random effect models were used for studies reporting the MI as a continuous or categorical variable. The pooled study results in this meta-analysis demonstrate a homogeneous statistically significant correlation between the MI and the rate of local recurrence after surgical resection regardless of the reporting method (continuous: HR = 1.20; categorical: HR = 2.65). However, significant limitations were noted, including the lack of a standardized method for MI calculation and heterogeneity of MI reports. We encourage the community to report their experience with the MI with greater precision and uniformity to further assess the influence of the MI on PFS within atypical meningiomas.
KW - Atypical meningioma
KW - Gross total resection
KW - Mitotic index
KW - Progression-free survival
KW - Recurrence
KW - Subtotal resection
KW - Surgical resection
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U2 - 10.1016/j.wneu.2020.06.189
DO - 10.1016/j.wneu.2020.06.189
M3 - Review article
C2 - 32615290
AN - SCOPUS:85088632858
SN - 1878-8750
VL - 142
SP - 191
EP - 196
JO - World neurosurgery
JF - World neurosurgery
ER -