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

To determine the long-term, spontaneous growth arrest rates in a large cohort of vestibular schwannoma patients. This paper describes a retrospective case series of 735 vestibular schwannoma patients organised into four groups: group A patients showed tumour growth which then stopped without any treatment; group B patients showed tumour growth which continued, but were managed conservatively; group C patients had a growing vestibular schwannoma and received active treatment; and group D patients had a stable, non-growing vestibular schwannoma. Demographics, tumour size and vestibular schwannoma growth rate (mm/month) were recorded. A total of 288 patients (39.2 per cent) had growing vestibular schwannomas. Of the patients, 103 (35.8 per cent) were managed conservatively, with 52 patients (50.5 per cent of the conservative management group, 18 per cent of the total growing vestibular schwannoma group) showing growth arrest, which occurred on average at four years following the diagnosis. Eighty-two per cent of vestibular schwannomas stopped growing within five years. Only differences between age ( = 0.016) and vestibular schwannoma size ( = 0.0008) were significant. Approximately 20 per cent of growing vestibular schwannomas spontaneously stop growing, predominantly within the first five years; this is important for long-term management.