Survival benefit of adjuvant radiotherapy in elderly patients with WHO grade Ⅲ meningioma.

BACKGROUND: The benefit of adjuvant radiotherapy (RT) is uncertain in elderly patients diagnosed with World Health Organization (WHO) grade III meningiomas. METHODS: The US National Cancer Database was used to identify elderly patients (aged over 60) with histologically confirmed WHO grade III meningiomas who underwent surgery with or without adjuvant external beam RT. Overall survival (OS) was evaluated by Kaplan-Meier analysis, multivariable Cox proportional hazard models, and propensity score-matched analysis. RESULTS: Among the 254 patients who met inclusion criteria, 151 (58.4%) underwent surgery followed by RT and 103 (41.6%) surgery without RT. The 5-year relative survival rate was 57.8% (95% confidence interval [CI]. 38.7%-85.4%) in the adjuvant RT group and 38.1% (95% CI, 21.9%-55.9%) in the group without RT when compared with age- and gender-matched US population. Adjuvant RT was associated with longer OS on both univariate (P = 0.011) and multivariable analyses (adjusted hazard ratio [AHR], 0.663; 95% CI, 0.449-0.978; P = 0.038). However, adjuvant RT did not significantly improve OS in a propensity score-matched analysis (P = 0.271) after matching the 2 cohorts on age, race, comorbidity, extent of resection, and tumor size. In patients who underwent subtotal resection or biopsy (n = 106), adjuvant RT significantly benefited OS on univariate analysis (P = 0.023), but did not show statistically significant benefit on multivariate analysis (AHR, 0.594; 95% CI, 0.337-1.046; P = 0.071). Adjuvant RT was not associated with improved OS in the elderly patients who underwent gross total resection (AHR, 0.764; 95% CI, 0.434-1.344; P = 0.350). CONCLUSION: Adjuvant external beam RT may not provide any survival benefit for elderly patients with WHO grade III meningioma after gross total resection.