J Neurol Surg B Skull Base 2014; 75 - A087
DOI: 10.1055/s-0034-1370493

Multimodality Treatment of 15 Malignant WHO III (2007 Criteria) Meningiomas: Differential Survival Rates Between De Novo and Progressive Origins

Philip D. Tatman 1, Joshua Osbun 1, Owais Ahmad 1, Maciej M. Mrugala 1, Jason K. Rockhill 1, Lois Gonzalez-Cuyar 1, Donald Born 1, Manuel Ferreira Jr.1
  • 1Seattle, USA

Introduction: Malignant meningiomas pose a formidable challenge to treat. According to the World Health Organization's (WHO) 2007 grading scheme, the average life expectancy for patients after diagnosis of a malignant meningioma is three years. Neither radiation, chemotherapy, nor aggressive surgery have individually provided an effective solution to combat the poor patient outcome associated with these neoplasms. However, recent trends in the treatment of malignant meningiomas have shown that a multimodality approach can extend the life expectancy of patients with this disease. Moreover, the clinical pathology and prognosis associated with different malignant meningioma phenotypes have not been well characterized. Many cancers, such as breast cancer, have undergone extensive genetic and clinical characterization which has led to the development treatment paradigms specific to each phenotype.

Objective: The aim of our study focused on evaluating the efficacy of a multimodality treatment of patients with WHO grade III meningiomas, with an emphasis on identifying the most effective treatment courses. We also sought to identify repetitive clinical presentations, in an attempt to group similar phenotypes within the grade III category, for future genetic and proteomic analysis.

Methods and Materials: 15 patients who sought treatment within the University of Washington Medical system, between the dates of January 1st, 1998 and August 1st, 2013, and had a meningioma which meet the WHO 2007 criteria were included in this study. Data points were collected from patient records within the University of Washington Medical Center, including letters from referring physicians at outside institutions. The Kaplain-Meier method, with a log regression analysis, was used to determine survival and recurrence times. A single variable cox regression model was utilized to analyze the efficacy and significance of each treatment moiety in relation to risk of patient death and disease recurrence.

Results: Seven of the original 15 patients were alive at the time of this study. The average time of survival from initial diagnosis to death was 3.01 years, with a five year survival rate of 46.3%. The use of adjunctive radiation therapy and/or chemo therapy revealed trends that reduced the risk of recurrence and death, although these trends were not statistically significant. Postoperative gamma knife resulted in the longest time of survival (3.51 years), which was followed by chemotherapy. Patients who received a de novo grade III diagnosis survived (4.92 years) longer than patients who received a lower grade diagnosis which progressed to a grade III diagnosis (2.37 years).

Conclusion: The patients in this series who elected to have radiation therapy and/or chemotherapy with their primary operation had an increased time of survival. Most of these patients elected to undergo several courses of chemotherapy and radiation in addition to multiple resections, which supports a multimodality treatment course. Patients who were diagnosed with a grade III meningioma de novo lived twice as long as patients with a previous diagnosis of lower grade meningioma. Based on our experience with these neoplasms, the authors support the use of postoperative adjuvant treatments, specifically gamma knife and chemotherapy, for the treatment of malignant meningiomas.