J Neurol Surg B Skull Base 2016; 77 - FP-14-07
DOI: 10.1055/s-0036-1592512

Long-Term Outcome and Prognostic Factors in Non-Benign Meningiomas

Christian Schichor 1, Anna-Maria Biczok 1, Kraus Theo 2, Niklas Thon 1, Jörg-Christian Tonn 1
  • 1Department of Neurosurgery, Ludwig-Maximilians University, Munich, Germany
  • 2Department of Neuropathology, Ludwig-Maximilians University, Munich, Germany

Background: In atypical (WHO II) and anaplastic meningioma (WHO III) microsurgical resection is the standard of care. However, optimal timing and value of adjuvant radiotherapy remain controversial. In this long-term retrospective study, we investigated the influence of clinical, histopathological, procedure-related and adjuvant treatment factors on progression-free-survival (PFS) and overall survival (OS).

Methods: Patients operated between 2001 and 2014 on histologically confirmed newly diagnosed WHO II and WHO III meningioma were included. Pre-operative MR-morphological features and patient-related data were obtained as well as extent of resection (gross total (GTR) or subtotal (STR) resection), histopathological characteristics and timing of adjuvant treatment. Recurrence or progression was determined by serial magnetic resonance imaging. Long-term data on progression-free and overall survival were collected by reviewing our in-house database or telephone interviews.

Results: A total of 92 patients (WHO II n = 75, WHO III n = 17) were included. Mean age at microsurgical resection was 62.9 (range: 26–89 years). Out of these patients 30 received adjuvant radiotherapy immediately after microsurgical resection (WHO II: n = 17/75, WHO III: n = 13/17). During the median follow up time of 58.8 months 27 patients died (WHO II: n = 13, WHO III: n = 14). 52 patients experienced a progression or recurrence. Mean OS time was 38 months, mean PFS time 18 months. The median 3-year PFS was 44% for WHO Grade II and 18% for WHO Grade III meningioma, respectively. In WHO II meningiomas presence of peritumoral edema or inhomogeneous contrast-enhancement as well as histologically proven brain invasion were associated with a poorer PFS and OS. GTR in WHO II patients resulted in significantly lower recurrence rates (p = 0.001, HR=3.31). In WHO II meningiomas adjuvant radiotherapy of the postoperative remnant tumor tissue immediately after STR (n = 12/33 patients) did not significantly influence local tumor control rate and OS. In case of secondary malignant transformation (n = 7/20 patients), PFS was significantly reduced (p = 0.05, HR=2.25).

Conclusion: Subtotal microsurgical resection as well as presence of brain invasion is associated with a higher risk of recurrence in newly diagnosed WHO II meningiomas. These factors as well as secondary malignant transformation correlate with overall survival.