Liquid Biopsy and Colorectal Cancer.

The majority of patients with colorectal cancer (CRC) will ultimately develop metastasis. Identifying specific molecular characteristics in them can help optimize their management in a personalized manner. This requires a noninvasive method for frequent sampling. Liquid biopsy provides such an option that is gaining increasing importance in most tumor types. We present the current status of liquid biopsy in CRC with respect to early diagnosis in high-risk population, screening, follow-up of patients on treatment, early identification of progression, and value of serial sampling. We will also discuss the potential for liquid biopsy to help identify changes related to microbiota, specific tumor-causing bacteria, and testing for ribonucleic acid associated with exosomes.