Inclusion Criteria:  Age 18-80 years;  histologically proven colorectal liver metastasis  With liver-dominant disease (extrahepatic metastases limited to lung metastases)  ECOG 0-1  A life expectancy of ≥ 3 months  Adequate hematologic function: absolute neutrophil count (ANC)≥1.5×109/l, platelets≥75×109/l, and international normalized ratio (INR) ≤1.3  Adequate liver and renal function: total bilirubin ≤2.0 mg/dl, alanine aminotransferase, aspartate aminotransferase ≤ 5x upper limit of normal, and albumin≥2.5 g/dl, serum creatinine≤2.0 mg/dl  Written informed consent for participation in the trial.  Exclusion Criteria:  Other previous malignancy within 5 years  Have metastases other than liver and lung metastases  Receiving any treatment before first blood collection