Bevacizumab for progressive vestibular schwannoma in neurofibromatosis type 2:  a retrospective review of 31 patients.
OBJECTIVE
Early studies suggest that bevacizumab treatment can result in tumor shrinkage and hearing improvement for some patients with neurofibromatosis type 2 (NF2). The aim of this study was to report extended follow-up in a larger cohort of similarly treated patients.


METHODS
Retrospective study.


METHODS
Tertiary referral center


METHODS
Thirty-one consecutive NF2 patients who received bevacizumab for progressive vestibular schwannomas.


METHODS
Hearing improvement, defined as an improvement in word recognition score above the 95% critical difference compared with baseline, and radiographic response, defined as a 20% or greater decrease in tumor volume compared with baseline.


RESULTS
The median age was 26 years (range, 12-73 yr). The median volumetric tumor growth rate before treatment was 64% per year. At the time of analysis, the median duration of treatment was 14 months (range, 6-41 mo) with a total of 47 patient-years of follow-up. A hearing response occurred in 57% (13/23) of evaluable patients and a radiographic response in 55% (17/31) of target vestibular schwannomas. The median time to response was 3 months for both end points. The only clinical or radiographic feature at baseline that correlated with change in tumor volume at 3 months was the mean apparent diffusion coefficient value, a radiologic marker of edema (p = 0.036). Ninety percent of patients had stable or improved hearing after 1 year of treatment and 61% at 3 years; 88% of patients had stable or decreased tumor size after 1 year of treatment and 54% at 3 years. Overall, treatment was well tolerated.


CONCLUSIONS
Bevacizumab treatment was followed by hearing improvement and tumor shrinkage in more than 50% of progressive vestibular schwannomas in NF2 patients. Stable or improved hearing was retained in the majority of patients.
Department of Neurology and Cancer Center, Massachusetts General Hospital, Boston 02114, USA. splotkin@partners.org
Scott R
SR
Plotkin
Vanessa L
VL
Merker
Chris
C
Halpin
Dominique
D
Jennings
Michael J
MJ
McKenna
Gordon J
GJ
Harris
Fred G
FG
Barker
D000293:Adolescent; D000328:Adult; D000368:Aged; D020533:Angiogenesis Inhibitors / Q000009:adverse effects / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized / Q000009:adverse effects / Q000627:therapeutic use*; D001301:Audiometry, Pure-Tone; D000068258:Bevacizumab; D002648:Child; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D034381:Hearing Loss / Q000209:etiology / Q000517:prevention & control; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D016518:Neurofibromatosis 2 / Q000150:complications*; D009464:Neuroma, Acoustic / Q000188:drug therapy* / Q000209:etiology*; D012189:Retrospective Studies; D016896:Treatment Outcome; D042461:Vascular Endothelial Growth Factor A / Q000037:antagonists & inhibitors; D055815:Young Adult
D020533:Angiogenesis Inhibitors; D061067:Antibodies, Monoclonal, Humanized; D042461:Vascular Endothelial Growth Factor A; D000068258:Bevacizumab