RESUMO
OBJECTIVE: Bevacizumab is the only anti-angiogenic agent approved in first-line therapy for metastatic colorectal cancer (mCRC). Although chemotherapy plus bevacizumab has led to improve outcomes for mCRC patients and is a common choice for first-line treatment of mCRC, previous research has established no prominent biomarker that can help to select patients who may benefit from bevacizumab in order to improve cost-effectiveness and therapeutic outcomes. The aim of this study was to compare pre- and post-therapeutic VEGF immunohistochemical (IHC) expression in mCRC patients treated with FOLFIRI plus bevacizumab to identify its potential role as a predictive biomarker. METHODS: A total of 57 mCRC patients who underwent FOLFIRI combined with bevacizumab chemotherapy as a first-line neoadjuvant regimen were enrolled and clinical outcome data analyzed. RESULTS: Low post-therapeutic VEGF expression (P < 0.001) and decreased peri-therapeutic VEGF expression (P < 0.001) were significantly predictive factors of responders. Furthermore, the 6-month progression-free survival (PFS) rate in mCRC patients with decreased peri-therapeutic VEGF expression was significantly better than the rate for those patients with no peri-therapeutic VEGF expression alterations (P = 0.033). CONCLUSIONS: Decreased peri-therapeutic VEGF expression in mCRC patients could probably be used to predict responsiveness to bevacizumab and subsequent PFS in clinical practice.