In recent years, the rapid development of next-generation sequencing (NGS) technologies has led to a significant reduction in sequencing cost with improved accuracy. In the area of liquid biopsy, NGS has been applied to sequence circulating tumor DNA (ctDNA). Since ctDNA is the DNA fragments released by tumor cells, it can provide a molecular profile of cancer. Liquid biopsy can be applied to all stages of cancer diagnosis and treatment, allowing non-invasive and real-time monitoring of disease development. The most promising aspects of liquid biopsy in cancer applications are cancer screening and early diagnosis because they can lead to better survival results and less disease burden. Although many ctDNA sequencing methods have enough sensitivity to detect extremely low levels of mutation frequency at the early stage of cancer, how to effectively implement them in population screening settings remains challenging. This paper focuses on the application of liquid biopsy in the early screening and diagnosis of cancer, introduces NGS-related methods, reviews recent progress, summarizes challenges, and discusses future research directions.

中文翻译：

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液体活检的下一代测序：癌症筛查和早期检测。

近年来，下一代测序（NGS）技术的飞速发展已大大降低了测序成本，并提高了准确性。在液体活检领域，NGS已应用于对循环肿瘤DNA（ctDNA）进行测序。由于ctDNA是肿瘤细胞释放的DNA片段，因此它可以提供癌症的分子特征。液体活检可应用于癌症诊断和治疗的所有阶段，从而可以无创且实时地监测疾病的发展。液体活检在癌症应用中最有希望的方面是癌症筛查和早期诊断，因为它们可以导致更好的生存结果和更少的疾病负担。尽管许多ctDNA测序方法都具有足够的灵敏度来检测癌症早期的极低水平的突变频率，如何在人群筛查环境中有效实施这些措施仍然具有挑战性。本文重点介绍液体活检在癌症的早期筛查和诊断中的应用，介绍NGS相关方法，回顾近期进展，总结挑战，并讨论未来的研究方向。