Pathologic Characteristics Associated With Local Recurrence of Atypical Meningiomas Following Surgical Resection

BACKGROUND: Optimal management of grade II meningiomas following resection remains controversial, owing mostly to the heterogeneity of post-operative (post-op) recurrence patterns across studies. Improved risk stratification of these patients would ensure that only those most at risk of recurrence would undergo appropriate post-op radiation therapy (RT). METHODS: Medical records from patients who underwent resection for grade II meningiomas were retrospectively reviewed. Demographic, disease characteristics, treatment, and clinical course data were retrospectively collected. Logistic regression, Cox proportional hazards modeling, and Kaplan-Meier curves with log rank testing were conducted to describe any potential relationships with time of recurrence. RESULTS: Of the 49 patients identified, 18 (36.7%) suffered a local recurrence following resection with a median follow-up of 3.1 years (range: 0.23 - 17.1 years). Past recurrence of the meningioma (P = 0.002) and extent of resection (P = 0.02) were significantly associated with local recurrence. On multivariable analysis, only prior meningioma recurrence was associated with time to local failure (P = 0.021). No histopathologic factors were found to be associated with the initial local failure. Of those who suffered a local recurrence, the presence of bone invasion (hazard ratio: 0.069, P = 0.008) and lack of salvage RT (P = 0.02) were associated with subsequent local failure. CONCLUSIONS: Currently considered histopathologic factors appear not to be helpful in guiding initial treatment course. History of prior local failure and bone invasion appear to be associated with multiple recurrences. Optimal surgical resection is critical to improving outcomes, and salvage RT may reduce subsequent local failure.