The Association Between Age and Outcomes of Bevacizumab Treatment in NF2-Related Schwannomatosis.

OBJECTIVE

NF2-related schwannomatosis (NF2-SWN) is an autosomal dominant genetic disorder characterized by the development of schwannomas, meningiomas, and spinal ependymomas. Treatment with bevacizumab, a monoclonal antibody against VEGF, has been shown to result in decreased vestibular schwannoma size and hearing improvement in ~50% of NF2-SWN patients. It is unknown whether the same degree of benefit is seen in younger patients compared with older patients. The objective of this study is to determine the association between age and bevacizumab treatment outcomes in NF2-SWN.

STUDY

DESIGN

Retrospective cohort study.

SETTING

Tertiary referral center.

PATIENTS: Thirty-seven patients with NF2-SWN.

INTERVENTIONS: Bevacizumab.

MAIN OUTCOME MEASURES: Change in tumor size of 20% or more.

RESULTS

This study includes 37 patients with NF2-SWN who were treated with bevacizumab at our institution between 2014 and 2024. They were divided into 2 groups: 22 adults over the age of 25 (26 to 71 y) and 15 adolescent and young adult (AYA) patients under the age of 25 (12 to 24 y). The median treatment duration was 2.1 years. A significantly higher proportion of AYA schwannomas (37.5%, n=9) exhibited radiographic tumor progression during the treatment period compared with those of the older patient group (11.9%, n=5) ( P =0.026), despite similar pre-treatment growth rates. There was no significant difference in the proportion of older and younger patients with hearing decline, improvement, or stability ( P >0.05).

CONCLUSIONS

AYA patients were significantly more likely to exhibit progression of tumor growth during bevacizumab treatment compared with older patients, though no significant differences were detected in hearing outcomes.