Abstract: Circulating tumor cells (CTCs) play an important role in tumor metastasis. Detections of CTCs are contribute to tumor treatment, which can provide reliable basis for predicting the prognosis and efficacy. CTCs are related to the staging and distant metastasis of non-small cell lung cancer (NSCLC). The number changes of CTCs are associated with the chemotherapy and radiotherapy effects and prognosis in NSCLC. Almost the same phenomena have been discovered in small cell lung cancer. In the future, CTCs may be used to monitor the occurrence of drug resistant tumor cells and help individual therapy for lung cancer.

Key words: Lung neoplasms, Neoplasm metastasis, Targeted therapy