This project is the first application, which is applied as a single center project and applied according to the screening quantity. This project is a multi-omics approach to explore biomarkers associated with prognosis after secondary radical resection of recurrent and metastatic colorectal cancer.

Main research objectives: 1. To detect DNA mutation and methylation in tumor tissues by NGS detection technology (the methylation dimension should be detected in adjacent tissues at the same time), and to explore specific molecular markers related to prognosis; 2. Using NGS test technology of blood in patients with preoperative and postoperative blood ctDNA mutations and methylation double dimension testing, respectively, to explore the preoperative and postoperative ctDNA mutations and the correlation between methylation status and recurrence, including but not limited to predict patients with recurrence of sensitivity, specificity, positive predictive value, negative predictive value and recurrence warning time and other indicators.

Main contents: This study intends to include single site for the first time/organ metastasis after radical treatment and surgical indications again in patients with colorectal adenocarcinoma (including but not limited to spread to the liver, lung metastasis, peritoneal metastasis, lymph node metastasis and other organ metastasis), collected in patients with preoperative peripheral blood and tissue samples, tissue adjacent to carcinoma and postoperative peripheral blood, NGS detection technology was used to detect DNA and mutation in the relevant samples, combined with clinical treatment and prognosis information of patients, and then explore biomarkers for predicting recurrence risk.

Inclusion Criteria:

1. Colorectal cancer patients with first recurrence and metastasis after previous radical resection
2. Single site/organ metastasis is indicative of reoperation
3. Adenocarcinoma diagnosed by histology or cytology
4. At the time of signing the informed consent, the applicant must be 18 years old or older
5. Life expectancy is at least 12 weeks
6. ECOG score 0~1

Exclusion Criteria:

1. Currently participating in the intervention study treatment, or receiving other drugs or study devices within 4 weeks before enrollment
2. Concurrent with other malignant tumors
3. The investigator determined that the patient had other serious diseases that might affect follow-up and short-term survival
4. Cardiac function NYHA class III or IV heart disease
5. The presence of definite peripheral nerve disease
6. There is definite hearing loss
7. Other researchers think it is not suitable for inclusion

Patients with various types of metastatic colorectal cancer who had underwent the radical resection of colorectal cancer and are planning to undergo radical resection of metastasis