How many growing vestibular schwannomas tend to stop growing without any treatment?

Objective: To determine the long-term, spontaneous growth arrest rates in a large cohort of Vestibular Schwannomas (VS). Methods: Retrospective case series of 735 VS patients organised in four groups: A patients with growing VS that stopped growing, B with growing VS and conservative management, C with growing VS and active treatment, and D with stable VS. We recorded demographics, tumour sizes and VS growth rate (mm/month). Results: 288 patients (39.2%) had growing VSs; 103 patients (35.8%) were managed conservatively with 52 patients (50.5% of the conservative-management group, 18% of the total growing VS) showing growth arrest, which occurred on average 4 years following the diagnosis; 82% of VS stopped growing within 5 years. Only differences between age (p = 0.016), and VS size (p = 0.0008) were significant. Conclusion: Approximately 20% of growing VS will stop growing spontaneously, predominantly within the first 5 years; this is important for long-term management