The effectiveness of Bevacizumab has been demonstrated for the treatment of metastatic colorectal cancer. However, the minimum number of bevacizumab cycles needed to improve overall survival is unknown. In addition, anti-angiogenic treatment has been shown in preclinical studies to accelerate metastasis. To investigate these two issues, we performed a retrospective case-control study in Chinese patients with metastatic colorectal cancer. Patients initially diagnosed as metastatic colorectal cancer at the Sun Yat-sen University Cancer Center from 2004 to 2010 were recruited. All patients treated with bevacizumab served as experimental group; patients not treated with bevacizumab were control group. The primary endpoints were overall survival and the incidence of new metastatic lesions in the liver and other organs.The top open access journals are peer reviewed scholarly journals of [chemotherapy]. The top open access journals are freely available on the public internet domain, allowing any end users to read, download, copy, distribute, prink, search or link to the full texts of the articles. These provide high quality, meticulously reviewed and rapid publication, to cater the insistent need of scientific community. These journals are indexed with all their citations noted. The top open access journals are indexed in MEDLINE, PUBMED, SCOPUS, COPERNICUS, CAS, EBSCO and ISI