Atypical and Malignant Meningiomas: Patterns of Care in Use of Adjuvant Radiation

Abstract

The National Comprehensive Cancer Network recommends adjuvant radiation therapy (RT) for Grade III meningioma, however, its role in Grade II disease remains unclear. In this study the National Cancer Data Base (NCDB) was used to assess the patterns of care and survival of patients with grade II and III meningiomas. The NCDB was queried for patients with WHO Grade II or III meningiomas who had undergone subtotal or gross total resection between 2010 – 2012. All cases must have had documentation regarding receipt of RT and those who survived ≤6 months were excluded. Demographic, clinical, and treatment details were compared between those who did and did not receive RT. Kaplan-Meier analysis was used to compare overall survival between these two groups and compared via the log-rank test. Univariable and multivariable logistic regression was used to assess for predictors of RT use. Univariable and multivariable Cox regression analysis were used to identify potential prognostic factors for survival. A total of 3,271 patients were included, with a median follow-up of 30.3 months. There were 2,985 (91.3%) with Grade II disease of which 741 (24.8%) received RT to a median dose of 5400cGy. There were 286 (8.7%) with Grade III disease, of which 170 (59.4%) received RT to a median dose of 6,000cGy. On multivariable logistic regression, the strongest predictor for the receipt of RT was grade 3 disease (OR 4.30, 95% CI 3.28-5.64, p<0.001), followed by increasing tumor size (OR 1.44-1.55), while the presence of a gross total resection (OR 0.69, 95% CI 0.58-0.81, p<0.001) and increasing Charlson/Deyo score (OR 0.61-0.70) were associated with decreased likelihood of RT. There were no significant survival differences based on RT. The 3-year overall survival was 89.1% for surgery alone compared to 88.4% for RT (p=0.86). On multivariable Cox regression, female gender (HR 0.60, 95% CI 0.47-0.75, p<0.001) and treatment at an academic center (HR 0.74, 95% CI 0.59-0.93, p=0.01) were associated with improved survival. Receipt of RT (HR 0.94, 95% CI 0.73-1.22, p=0.64) was not associated with an improvement in overall survival. Most patients (>70%) in this large hospital-based study of patients with Grade II or III meningioma did not receive RT. There was no survival benefit noted for those who did receive RT.