Circulating Tumor Cells Culture: Methods, Challenges, and Clinical Applications

Abstract Circulating tumor cells (CTCs) play a pivotal role in cancer metastasis and hold considerable potential for clinical diagnosis, therapeutic monitoring, and prognostic evaluation. Nevertheless, the limited quantity of CTCs in liquid biopsy samples poses challenges for comprehensive downstream analysis. In vitro culture of CTCs can effectively address the issue of insufficient CTC numbers. Furthermore, research based on CTC cell lines serves as a valuable complement to traditional cancer cell line‐based research. While numerous reports exist on CTC in vitro culture and even the establishment of CTC cell lines, the methods used vary, leading to disparate culture outcomes. This review presents the developmental history and current status of CTC in vitro culture research. Additionally, the culture strategies applied in different methods and analyzed the impact of various steps on culture outcomes are compared. Overall, the review indicates that while the short‐term culture of CTCs is relatively straightforward, long‐term culture success has been achieved for various specific cancer types but still faces challenges. Further optimization of efficient and widely applicable culture strategies is needed. Additionally, ongoing applications of CTC in vitro culture are summarized, highlighting the potential of expanded CTCs for drug susceptibility testing and as therapeutic tools in personalized treatment.