The most important prognostic factor regarding tumor recurrence is the pathological grade. In WHO grade I tumors, the chance of recurrence is 7–25%, in grade II 29–59%, whereas, in grade III, it is 60–94% [17]. In our study, the 5-year recurrence of grade 2 and 3 meningiomas were 36.0%(n = 31) and 56.6% (n = 30), respectively (P = 0.014). The 5-year OS of grade 2 and 3 meningiomas were 82.6% (n = 71) and 67.9% (n = 36), respectively (P = 0.038). GTR has been widely recognized as a favorable factor that was strongly associated with better survival [18, 19]. A retrospective study of 132 atypical meningioma cases revealed that GTR was associated with better PFS, but not OS [20]. In a series of 44 patients, Zaher reported that patients with GTR had longer OS than patients with STR (75 vs 46 months) [21]. Our data are consistent with previous reports showing that patients who underwent GTR had favorable outcomes. In our study, the 5-year recurrence of GTR and STR were 35.9%(n = 33) and 59.6% (n = 28), respectively (P = 0.007). The 5-year OS of GTR and STR were 84.8% (n = 78) and 61.7% (n = 29), respectively (P = 0.003). There were significant differences in the 5-year recurrence and OS between GTR and STR.
Complete surgical resection is considered the gold standard for treatment. However, this approach is often not sufficient in WHO grade II and III meningiomas. The importance of deregulated cell signaling pathways as drivers of neoplastic transformation is increasingly getting attention. Several studies have suggested a critical role of VEGF in meningioma pathogenesis, as its expression correlates with tumor grade, peritumoral edema, and necrosis [22, 23]. For this reason, in the last few years, antiangiogenetic factors have been used, not only for malignant glial brain tumors but also for meningiomas not responsive to standard treatments [24]. Bevacizumab is a monoclonal antibody against VEGF. Few studies described its use in grade II and III meningiomas [25]. In our study, the purpose of BV is to alleviate the symptoms of PTBE. The Chi-square test showed that there were significant differences in PFS-12, PFS-36, M-PFS, OS-12, OS-36, and M-OS between the BV group and the non-BV group. The log-rank test indicated significant differences in PFS and OS between the BV group and the non-BV group. Thus, we believe that BV can reduce the recurrence and improve PFS and OS in patients with HGMs.
KPS in the BV group was significantly improved after treatment. Surgery can alleviate the symptoms of PTBE to a certain extent. Considering the obvious changes of KPS in the BV group pre- and post-treatment, we believe that BV can alleviate PTBE and improve the quality of life of patients. There are some treatments such as reoperation, GSRS, and medicine therapy that can be chosen after recurrence. These patients who received both reoperation and GSRS after recurrence have a better outcome than others. Therefore, GSRS is a recommended treatment option. The OS of patients who refused treatment was short. We recommend that patients with HGMs receive active treatment after recurrence.
The adverse reactions of BV include hypertension, various bleeding, venous thrombus exfoliation, and albuminuria. In previous reports, the incidence of all kinds of bleeding was 30%, including intracranial hemorrhage, epistaxis, gingival bleeding, conjunctival bleeding, injection-site bleeding, and hematuria [26]. Besse reported in 2010 that the incidence of brain hemorrhage in patients with brain metastases after applicated BV was 0.8%-3.3%, while the incidence of non- applicated was 1.0% [27]. Khasraw reported in 2012 that the incidence of brain hemorrhage in patients with glioma or brain metastases after BV treatment was 3.7%, while the incidence of non-BV was 3.6% [28]. Due to the low dose of BV in this study, only 8 patients developed hypertension.