High-dose FOLFIRI in Advanced Colorectal Cancer Patients With Wild-type UGT1A1*6 and *28

Inclusion Criteria:

* Patients should be histologically diagnosed with advanced colorectal adenocarcinoma or postoperative recurrence
* Patients should be with UGT1A1\*28 wild-type TA6/6 and UGT1A1\*6 wild-type G/G
* Patients have measurable lesions
* Patients are not available for targeted therapy or patients refuse to receive targeted therapy
* Age should be more than 18 years
* Performance status should be 0-2
* Hemoglobin should be more than 9.0 g/dL; Absolute Neutrophil Count should be more than 1,500/mm3; Platelet should be more than 80,000/mm3；Total Bilirubin should be less than 1.5 times of the upper limit of normal value; Alanine aminotransferase and Glutamic-oxaloacetic transaminase should less than 2.5 times of the upper limit of normal value (it can be 5 times if liver metastasis); Creatinine should be be less than 1.5 times of the upper limit of normal value

Exclusion Criteria:

* Patients with UGT1A1\*28 wild-type TA6/7, TA7/7 and UGT1A1\*6 wild-type G/A,A/A;
* Patients with brain metastases;
* Patients could not tolerate chemotherapy;
* Patients have secondary primary tumor;