The impact of bevacizumab on the occurrence and recurrence of intracranial brain metastases in non-small cell lung cancer (NSCLC) patients.

Abstract

2081 Background: Patients (pts) with brain metastases (BM) have a poor prognosis and limited treatment options. Approximately 40-50% of pts with NSCLC will develop BM during the course of their disease. A better understanding of the pathobiology of BM and the development of targeted agents hold promise for improved prophylaxis and therapy of BM which could have significant impact on disease progression and pt's survival. Vascular Endothelial Growth Factor has been implicated in setting up a metastatic niche allowing cells to seed and grow in the brain parenchyma. Inhibition of this signaling has been studied and shown to be effective in reducing BM in animal models. Methods: The objective of this retrospective study was to determine whether bevacizumab decreases the incidence and or the recurrence of BM in pts with NSCLC. We retrospectively identified NSCLC pts with and without BM treated with bevacizumab. The primary endpoint was the proportion of patients who developed BM on or after bevacizumab therapy. Secondary endpoints were rate of local or regional recurrence after stereotactic radiosurgery (SRS). Occurrence of BM was evaluated by retrospectively reviewing MRI and or CT scans. Results: A total of 30 pts with stage IV non-squamous NSCLC who had no BM at diagnosis treated with bevacizumab (Non-BM group, NBMG) and 85 pts with non-squamous NSCLC who had BM and underwent SRS (BM group, BMG) were studied (46%M; median age 60 years (range 32-84). In the NBMG, 28% of pts developed BM. Median time to development of BM was 10.5 months. In the BMG, 4 pts were treated with bevacizumab following SRS. Of these 4 pts, 3 pts (75%) had no recurrence while 1 pt (25%) developed local then regional recurrence at 7 and 9 months, respectively. Of the remaining 81 pts who underwent SRS but never received bevacizumab, 27% of pts had local recurrence and 41% had regional recurrence at median time of 4 and 4.5 months, respectively. Conclusions: Bevacizumab may have a role in the treatment of NSCLC in regards to development and recurrence of brain metastases. These results support the need for further prospective investigation in a larger patient population with matched controls.