Currently, schwannomas and neurofibromas, as well as MPNSTs, are treated with resection and extends to the use of adjunctive treatments for postoperative management, including the use of chemo- and radiotherapies. Avastin is a drug that has recently piqued interest. Dr. Scott Plotkin presented the initial results of Massachusetts General Hospital’s experience with bevacizumab (Avastin) in neurofobromatosis (NF)-2 at the American Association of Neurological Surgeons meeting on May 4, 2009. Similar information ws resented at this meeting in 2008. They presented their results with regard to tumor size and hearing improvement from ten consecutive patients. The author’s rationale for using avastin arose out of previous research in which they found that sporadic vestibular schwannomas universally expressed VEGF, a receptor targeted by avastin.
They found that while nine out of ten tumors shrunk with avastin, only 6 did so significantly (i.e. greater than 20% reduction in volume). One progressed in spite of treatment, and two that responded to avastin initially began to grow again during follow-up. In terms of hearing improvement, only seven patients were eligible and they noted improvement in word recognition scores in four of the seven patients; two patients had ‘stable hearing’ and one experienced progressive hearing loss. One patient, identified only as case #2, responded dramatically to avastin, with an improvement in word recognition from 8% to 96%.
That noted, peer-reviewed reports have not yet been published and no prospective studies ahve been conducted. Avastin remains a promising but experimental treatment for NF-2 related schwannomas.