# Extrachromosomal Circular DNA in Cancer: Mechanisms and Clinical Applications

## TL;DR

Extrachromosomal circular DNA (eccDNA) is a significant factor in cancer development and drug resistance, with potential for use in diagnosis and treatment.

## Contribution

This review highlights recent advancements in understanding eccDNA's role in cancer and its translational potential for clinical applications.

## Key findings

- eccDNA contributes to cancer progression through genomic instability and oncogene amplification.
- It enhances tumour cell adaptability and is linked to drug resistance.
- eccDNA shows promise as a biomarker and therapeutic target in cancer.

## Abstract

Extrachromosomal circular DNA (eccDNA) has emerged as a critical area of cancer research due to its ubiquitous presence in tumour cells and significant role in tumorigenesis, progression and drug resistance. Recent studies demonstrate that eccDNA promotes cancer progression by influencing genomic instability, amplifying oncogenes, regulating gene expression and enhancing tumour cell adaptability to adverse conditions. While the precise mechanisms underlying eccDNA formation and its biological functions remain unclear, its potential applications in cancer diagnosis, prognosis and targeted therapy are gaining increasing recognition. This review summarises the latest advancements in eccDNA research, highlighting its potential as both a biomarker and a therapeutic target. Additionally, it emphasises the translational potential of eccDNA in clinical diagnostics and personalised treatment strategies, offering new perspectives for future cancer research and innovative therapies.