Cancer can be caused by various factors, including the malfunction of tumor suppressor genes and the hyper-activation of proto-oncogenes. Tumor-associated extrachromosomal circular DNA (eccDNA) has been shown to adversely affect human health and accelerate malignant actions. Whole-genome sequencing (WGS) on different cancer types suggested that the amplification of ecDNA has increased the oncogene copy number in various cancers. The unique structure and function of ecDNA, its profound significance in cancer, and its help in the comprehension of current cancer genome maps, renders it as a hotspot to explore the tumor pathogenesis and evolution. Illumination of the basic mechanisms of ecDNA may provide more insights into cancer therapeutics. Despite the recent advances, different features of ecDNA require further elucidation. In the present review, we primarily discussed the characteristics, biogenesis, genesis, and origin of ecDNA and later highlighted its functions in both tumorigenesis and therapeutic resistance of different cancers.

癌症可由多种因素引起，包括肿瘤抑制基因的功能障碍和原癌基因的过度激活。肿瘤相关的染色体外环状 DNA (eccDNA) 已被证明会对人类健康产生不利影响并加速恶性行为。不同癌症类型的全基因组测序 (WGS) 表明，ecDNA 的扩增增加了各种癌症中的癌基因拷贝数。ecDNA独特的结构和功能、其在癌症中的深远意义以及对理解当前癌症基因组图谱的帮助，使其成为探索肿瘤发病机制和进化的热点。阐明 ecDNA 的基本机制可能会为癌症治疗提供更多见解。尽管最近取得了进展，但 ecDNA 的不同特征需要进一步阐明。在本次审查中，