Background: Pre-treated patients with first-line treatment can be offered a second
treatment with the aim of improving their poor clinical prognosis. The therapy of metastatic
colorectal cancer (CRC) patients who did not respond to first-line therapy has limited treatment
options. Recently, many studies have paid much attention to the efficacy of bevacizumab as an
adjuvant treatment for metastatic colorectal cancer.
Objectives: We aimed to evaluate the efficacy and toxicity of bevacizumab plus chemotherapy
compared with bevacizumab-naive based chemotherapy as second-line treatment in people with
Methods: Electronic databases were searched for eligible studies updated to March 2018.
Randomized-controlled trials comparing addition of bevacizumab to chemotherapy without
bevacizumab in MCRC patients were included, of which, the main interesting results were the
efficacy and safety profiles of the addition of bevacizumab in patients with MCRC as second-line
Result: Five trials were eligible in the meta-analysis. Patients who received the combined
bevacizumab and chemotherapy treatment in MCRC as second-line therapy showed a longer overall
survival (OS) (OR=0.80,95%CI=0.72-0.89, P<0.0001) and progression-free survival (PFS)
(OR=0.69,95%CI=0.61-0.77, P<0.00001). In addition, there was no significant difference in
objective response rate (ORR) (RR=1.36,95%CI=0.82-2.24, P=0.23) or severe adverse event (SAE)
(RR=1.02,95%CI=0.88-1.19, P=0.78) between bevacizumab-based chemotherapy and bevacizumabnaive
Conclusion: Our results suggest that the addition of bevacizumab to the chemotherapy therapy
could be an efficient and safe treatment option for patients with metastatic colorectal cancer as
second-line therapy and without increasing the risk of an adverse event.