Abstract: Background and purpose: Current colorectal cancer patient-derived xenografts (PDXs) models were established by samples taken during surgery. However, metastatic colorectal cancer (mCRC) patients have less surgical opportunities, and it was difficult to obtain enough tumor fragment. The aim of the present study was to establish mCRC PDXs by image-guided biopsy. Methods: A total of 12 patients with colorectal cancer who underwent surgery were included. All patients had recurrent lesions or metastatic lesions needed to be histologically confirmed, and none of them had contraindication to biopsy. Tumor tissues not required for clinical diagnosis were used to establish mCRC PDXs. Results: Seven PDXs grew sufficiently for transfer into mice. The success rate was 77.8%. Conclusion: The PDXs established by image-guided biopsy had the advantage of convenient operation, good reproducibility, high achievement ratio, short experimental periodicity and reliably retain specific genetic and morphological features of the primary patient tumors.

Key words: Biopsy, Metastatic colorectal cancer, Patient-derived xenografts models