Sex-specific difference in treatment success/failure after vestibular schwannoma treatment

Sex-related differences in patients with sporadic, unilateral vestibular schwannoma (VS) are poorly investigated so far, and it remains unclear whether biological sex affects treatment response to stereotactic radiosurgery (SRS) or microsurgical resection (SURGERY). This study elucidates sex-related differences in treatment outcome of VS.

This is a retrospective two-center cohort study. All consecutive patients treated for their VS between 2005 and 2012 were included. Previously treated VS and patients with neurofibromatosis were excluded. Clinical status and treatment-related complications were analyzed from both centers' prospective treatment registries. Recurrence/progression-free-survival was assessed radiographically by contrast-enhanced magnetic resonance imaging.

Within the entire patient cohort of N = 1,118, the majority of VS patients (56%) was female. Sixty-two percent of patients were treated by SRS. Females with very small tumors (KOOS I) were significantly less likely to be assigned to SURGERY than males (P = .009). Mean follow-up time was 6 ± 4.3 years. In SURGERY, the rate of subtotal resection was significantly higher in women (7%) compared to men (2%) (P = .041). However, there was no difference in long-term tumor control after SURGERY between both sexes (P = .729). In SRS however, the incidence of recurrence was significantly higher in women (14%) compared to men (8%) (P = .004), which was also reflected in the Kaplan-Meier analysis (P = .031).

Female sex was a negative prognostic factor for treatment success (long-term tumor control) if treated with SRS-there was no sex-related differences in long-term tumor control after SURGERY. Additional research is needed to elucidate sex-related differences in tumor biology affecting the response to VS treatment.