This study makes an observation over the objective response rate of Apatinib and 5-Fu combination regimen in the three-line treatment of metastatic colorectal cancer. All the participants will randomly receive the treatment of Apatinib and 5-Fu combination regimen or 5-Fu.

5-Fu chemotherapy is an effective therapy for colorectal cancer. Apatinib is a small-molecule tyrosine kinase inhibitor (TKI) that highly selectively binds to and strongly inhibits vascular endothelial growth factor receptor 2 (VEGFR-2), with a decrease in VEGF-mediated endothelial cell migration, proliferation, and tumor microvascular density. A phase II trail of Apatinib has been demonstrated that Apatinib is safe to treat the metastatic colorectal cancer and the disease control rate can reach 50%.

Inclusion Criteria:

• 18 and ≤ 70 years of age

  • Histological confirmed advanced or metastatic colorectal Cancer，at least one measurable lesion, larger than 10 mm in diameter by spiral CT scan(scanning layer ≤ 5 mm )
  • Have failed for ≥ 2 lines of chemotherapy
  • Life expectancy of more than 3 months
  • ECOG performance scale ≤ 1
  • Duration from the last therapy is more than 6 weeks for nitroso or mitomycin More than 4 weeks for operation, radiotherapy or cytotoxic agents
  • Adequate hepatic, renal, heart, and hematologic functions (platelets > 80 × 10E+9/L, neutrophil > 1.5 × 10E+9/L, serum creatinine ≤ 1×upper limit of normal(ULN), bilirubin < 1.25 ULN, and serum transaminase ≤ 2.5× ULN)
  • Child bearing potential, a negative urine or serum pregnancy test result before initiating apatinib, must agree and commit to the use of a reliable method of birth control for the duration of the study and for 8 weeks after the last dose of test article. Male: All subjects who are not surgically sterile or postmenopausal must agree and commit to the use of a reliable method of birth control for the duration of the study and for 8 weeks after the last dose of test article.
  • Signed and dated informed consent. Willingness and ability to comply with scheduled visits, treatment plans, laboratory tests, and other study procedure.

Exclusion Criteria:

• History of other malignancies except cured basal cell carcinoma of skin and carcinoma in-situ of uterine cervix
• Pregnant or lactating women
• Preexisting uncontrolled hypertension defined as more than 140/90 mmHg despite using single medical therapy, more than class I (NCI CTCAE 3.0 ) myocardial ischemia, arrhythmia(including QTcF:male ≥ 450 ms, female ≥ 470 ms), or cardiac insufficiency myocardial ischemia, arrhythmia, or cardiac insufficiency
• Before or at the same time any, second malignancies except cured basal cell carcinoma of skin and carcinoma in-situ of uterine cervix
• Any factors that influence the usage of oral administration Evidence of CNS metastasis
• URT: urine protein ≥ (++)and > 1.0 g of 24 h
• PT, APTT, TT, Fbg abnormal, having hemorrhagic tendency (eg. active peptic ulcer disease) or receiving the therapy of thrombolysis or anticoagulation
• Abuse of drugs
• Certain possibility of gastric or intestine hemorrhage
• Less than 4 weeks from the last clinical trial
• Viral hepatitis type B or type C
• Prior VEGFR inhibitor treatment
• Evidence of significant medical illness that in the investigator's judgment will substantially increase the risk associated with the subject's participation in and completion of the study