循环肿瘤细胞检测在结直肠癌中的应用及展望

Application and prospect of circulating tumor cells detection in coiorectal cancer

结直肠癌患者中有30％～50％会出现复发和转移。目前，对于结直肠癌患者术后复发、转移及预后还缺乏有效的评价手段。近年来，循环肿瘤细胞（CTC）在结直肠癌的诊断和治疗中取得了很大进展。常用的CTC检测方法包括：免疫细胞化学、流式细胞术、PCR酶聚反应、免疫磁珠分离检测法、光导纤维阵列扫描技术和CTC芯片等。根据目前的研究结果来看，学者们一致认为CTC在结直肠肿瘤中存在以下方面的临床应用价值，包括：（1）探明早期结直肠癌患者是否存在隐匿性的转移；（2）监测疾病的进展；（3）评估患者对治疗的反应。近年来，伴随着临床专科化的发展、多学科综合治疗模式的出现以及基因检测和靶向治疗的应用，个体化治疗可能使结直肠癌患者的总体生存率和无病生存期较以往有较大幅度的提高，但以上研究及分析都需依靠可获取的肿瘤组织进行。而在临床实际工作中．晚期或非手术患者取材困难，通过穿刺活检获得的肿瘤组织量较少，从而使检测基因表达和突变情况变得更加艰难。CTC检测从分子生物学角度为解决这一难题提供了可能，且具有高度可行性和可重复微创性，因此．外周血CTC检测可作为一种新型的诊断工具用于临床，相信其在结直肠癌的早期诊断、评估复发和转移、指导个体化治疗以及评价预后等方面将起到不可低估的作用。

About 30%-50% of colorectal cancer patients would develop recunence 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 immunoeytochemistry, 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 deteetion will play an important role in early diagnosis, evaluating recurrence, metastasis, making individualized treatment and predicting prognosis.