Do anti-angiogenic therapies prevent brain metastases in advanced renal cell carcinoma?

Abstract

BackgroundWe analyzed renal cell carcinoma (RCC) brain metastasis (BM) risk factors and compared BM occurrence in metastatic RCC (mRCC) treated with or without anti-angiogenic agents (AA). MethodsData from all consecutive metastatic RCC patients (patients) treated in a french cancer center between 1995 and 2008 were reviewed. Patients had histologically confirmed advanced RCC without synchronous BM at the time of metastasis diagnosis. AA were sorafenib, sunitinib and bevacizumab. We also included patients treated with mTor inhibitors, temsirolimus and everolimus, as they also demonstrated anti-angiogenic activities. Characteristics of the two groups treated with or without AA were compared with a Fisher exact test. Impact of AA on overall survival (OS) and cumulative rate of brain metastasis (CRBM) was explored by Kaplan-Meier method. ResultsOne hundred and ninety-nine patients with advanced RCC were identified, 51 treated with AA and 148 without AA. The median follow-up duration was 40 months. BM occurred in 35 patients. Characteristics between AA treated and non-AA treated groups were unbalanced and favoring better prognostic factors in AA treated group. Median OS was 24 months. AA treatment was not associated with a lower CRBM (HR=0.58 [0.26-1.30], P=0.187). Median survival free of BM was 11.8 months, CI95% (4.95-18.65) in the group without AA treatment and 28.9 months in the AA group, CI95% (18.64-39.16). Alkaline phosphatase (AP) was an independent prognostic factor for BM (P=0.05). In multivariate Cox model, after adjustment to AP, AA did not improve the CRBM (aHR=0.53 [0.22-1.32]). ConclusionIn this retrospective study, AA did not decrease significantly the CRBM. Elevated AP was a predictive factor for BM in mRCC.