Colorectal cancer (CRC) ranks third in global cancer incidence and second in cancerrelated mortality. CRC management involve surgery, chemotherapy, radiotherapy, imaging, pathology, and endoscopy. Systemic medical therapy is a critical component, and gene testing prior to treatment is recommended to guide targeted therapy.

1.Resectable nonmCRC patients – testing before adjuvant chemotherapy aids in regimen selection;

2.Unresectable nonmCRC patients – testing before treatment decision guides conversion or palliative therapy options;

3.All mCRC patients – testing before comprehensive treatment to tailor therapy based on RAS/BRAF and MSI status;

4.mCRC patients refractory to standard therapy – testing to identify suitable targeted or immunotherapeutic agents;

5.Patients clinically suspected of Lynch syndrome – testing for Lynch screening.

1. RAS, BRAF, HER2 mutation status – guides use of EGFR monoclonal antibodies, BRAF/MEK inhibitors, HER2 inhibitors, and provides prognostic information for CRC.

2. UGT1A1 and DPYD – guides irinotecan, 5-FU, capecitabine, and tegafur dosing.

3. MSI testing – predicts response to immune checkpoint inhibitors.

4. MSI and BRAF V600E – indicate Lynch syndrome risk.

1. Nucleic Acid Extraction

2. Library Preparation （3.5 hours total time）

3. Sequencing

4. Auto-data Analysis

5. Report