[Application and prospect of circulating tumor cells detection in colorectal cancer]

About 30%-50% of colorectal cancer patients would develop recurrence and metastasis. At present, there is still a lack of effective evaluation method for recurrence, metastasis and prognosis. In recent years, a great progress about circulating tumor cells (CTC) in diagnosis and treatment of colorectal cancer has been made. The most common CTC detection methods include immunocytochemistry, flow cytometry, PCR, immunomagnetic separation, optical fiber array scanning and CTC chip. Based on present studies, researchers reach the consensus that CTC is clinically valuable in the following aspects: detection of occult metastasis, monitor of disease progress and evaluation of response to treatment. With recent development of clinical specialization, multi-disciplinary treatment (MDT), gene detection and targeted therapy, individualized treatment may greatly improve overall survive and disease-free survival of colorectal cancer patients. However, the methods above depend on tumor tissues that are always impractical to obtain for late stage and non-surgery patients. Moreover, the size of specimen is always small, making gene expression and mutation detection difficult. CTC detection may solve such problems based on molecular biology with high plausibility and repeatability. Therefore, CTC detection can be used as a new diagnosis tool. It is believed that CTC detection will play an important role in early diagnosis, evaluating recurrence, metastasis, making individualized treatment and predicting prognosis.