The study aims to establish an organoids platform and apply them to screen drugs for advanced/recurrent/metastatic colorectal cancer patients.

The study was designed as a prospective, observational clinical trial in a single center. We establish organoids derived from patients with advanced/recurrent/metastatic colorectal cancer. Organoids will be validated with a combination of Next Generation Sequencing (NGS) analysis and histopathology. Drug screening assay will be performed on organoids with the chemotherapy and targeted agents, and the sensitivity and speciality will be compared with the clinical practice.

Inclusion Criteria:

1. Patients voluntarily participated in the study and signed informed consent;
2. ECOG score 0~2;
3. Expected survival over 6 months;
4. The serum or urine pregnancy test must be negative within 7 days before enrollment for the women of childbearing age who should agree that contraception must be used during the trial;
5. CBC: Hb≥70g/L、WBC≥3.5×109/ L 、ANC≥1.5×109/L、PLT≥80×109/L；
6. Serum ALT≤2×UL, AST≤2×ULN; Serum creatinine≤1.5×ULN；
7. Colorectal cancer was unresectable and confirmed as adenocarcinoma by histopathology. Patients have no significant symptoms in the primary lesion (no bleeding, perforation and obstruction in the primary focus). Besides, the carcinoma is potentially resectable but the patient refuses surgery;
8. Patients can comply with the research scheme according to the judgment of the researcher.

Exclusion Criteria:

1. Activity or uncontrol severe infection;
2. Liver cirrhosis, Decompensated liver disease;
3. History of immune deficiency, including HIV positive or suffering from a congenital immunodeficiency disease;
4. Chronic renal insufficiency or renal failure;
5. Other malignancies which diagnosed within 5 years or needed to be treated;
6. Myocardial infarction, severe arrhythmia and NYHA (New York heart association)≥2 for congestive heart failure
7. Concomitant diseases are treated by drugs that impair liver or kidney function, such as tuberculosis.

Patients suffered from advanced/recurrent/metastatic colorectal cancer which was diagnosed as adenocarcinoma and unresectable.

It involves patients' informed consent and research confidentiality.