Comparison of the effects of bevacizumab (BV) in combination with chemotherapy (CT) and CT alone on the incidence of brain metastases (BM) in non-small cell lung cancer (NSCLC): A retrospective clinical analysis.

Abstract

e19044 Background: The incidence of BM of advanced NSCLC is 20-40%, and there's a lack of effective treatment. This study aims to investigate the value of the angiogenesis marker VEGF in predicting the risk of BM in patients (pts) with NSCLC receiving CT+BV or CT alone and to explore the cumulative risk of BM of NSCLC with high VEGF expression that treated with BV. Methods: Pts with stage IIIB/IV NSCLC underwent CT and/or targeted therapy from 2008-1 to 2010-12 were included. Semi-quantitative detection of VEGF expression was carried out using conventional immunohistochemical staining of lung tissue specimens. Pts experienced BM prior to treatment were excluded. Pts underwent gemcitabine /carboplatin (GC) + BV treatment were included in observation group; pts underwent GC were included in control group. The cumulative risk of BM was calculated using death as a competing risk. Results: 177 pts were included (118 in BV+CT group; 59 in CT group). The median follow-up duration was 18.7 months. Up to 2012-12-31, BM occurred in 15 cases in BV+CT group and 17 in CT group (12.71% vs. 28.81%). 4 cases (33.89%) in BV+CT group survived, and 11 (18.64%) in CT group survived. In BV+CT group, the cumulative risks of BM at 6, 12, and 24 months were 0.86%, 7.52%, and 13.01%, respectively, and 6.74%, 18.88%, and 28.85% in CT group, respectively (P < 0.001). HR of BM in BV+CT group was 0.048 (95% CI: 0.171-0.994) compared to CT group. In BV+CT group, the 6-, 12-, and 24-month cumulative risks of BM were 1.6%, 7.97%, and 12.63% in pts with VEGF(+) and 0, 7.24%, and 12.71% in pts with VEGF(-), respectively; in CT group, the 6-, 12-, and 24-month cumulative risks of BM were 9.35%, 27.04%, and 37.5% in pts with VEGF(+) and 3.52%, 10.71%, and 18.05% in pts with VEGF(-), respectively; there was no significant difference between them. Conclusions: BV+CT can effectively reduce the incidence of BM in pts with advanced NSCLC and improve their prognosis. This small data sample suggests that pts with VEGF(+) are more prone to BM than pts with VEGF(-). The incidence of BM in pts with VEGF(+) is reduced after BV treatment, though its specific mechanism still requires further study.