Rebound tumour progression after the cessation of bevacizumab therapy in patients with recurrent high-grade glioma.

After withdrawal of bevacizumab in patients with recurrent high-grade glioma, we have observed a rapid tumour re-growth or "rebound" radiographic phenomenon with accelerated clinical decline. We retrospectively reviewed 11 patients treated at the Henry Ford Hermelin Brain Tumor Center with recurrent high-grade glioma who demonstrated a rebound progression pattern after the discontinuation of bevacizumab. The original tumour area-of-enhancement increased by a mean of 158%, when compared to the rebound magnetic resonance imaging. After rebound, no patients (0/8) showed a response to next-line treatments that did not include bevacizumab. The median survival of those re-treated with bevacizumab was 149 and 32 days for those who received other regimens. Abrupt discontinuation of bevacizumab after recurrence often leads to a dramatic rebound phenomenon and rapid clinical decline. Slow tapering of the bevacizumab dose after tumour progression may prevent this from occurring and improve responsiveness to next-line therapies.