Colorectal cancer (CRC) is a major cause of cancer-related death worldwide. Despite significant progress in the treatment of CRC, there is still a need for improved diagnostic and prognostic biomarkers to guide personalized treatment strategies. Liquid biopsy, the analysis of biological fluids such as blood, urine, or cerebrospinal fluid, has emerged as a promising tool for the detection and monitoring of cancer.
In this article, the authors review recent advances in the use of liquid biopsy components, including circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), and extracellular vesicles (EVs), as predictive and prognostic biomarkers in CRC.
CTCs are tumor cells that have detached from the primary tumor and entered the bloodstream. They are rare in circulation and are difficult to isolate and characterize. However, advances in technology have allowed for the detection and analysis of CTCs, which can provide information on the molecular and genetic characteristics of the tumor. The authors highlight several studies that have shown the prognostic value of CTCs in CRC, with higher CTC counts correlating with worse overall survival.
ctDNA refers to the DNA released from tumor cells into the bloodstream. ctDNA analysis can provide information on the mutational landscape of the tumor, allowing for the detection of genetic alterations that may be used as therapeutic targets. The authors discuss several studies that have demonstrated the potential of ctDNA as a diagnostic and prognostic biomarker in CRC. For example, ctDNA analysis has been shown to detect early-stage CRC with high accuracy and has also been associated with worse prognosis in advanced CRC.
EVs are small membrane-bound vesicles released by cells that contain various molecules such as proteins, lipids, and nucleic acids. Tumor-derived EVs can enter the bloodstream and may play a role in cancer progression and metastasis. The authors highlight several studies that have shown the potential of EVs as biomarkers in CRC, with EVs containing specific miRNAs and proteins correlating with worse prognosis and disease progression.
The authors also discuss the potential of combining multiple liquid biopsy components to improve diagnostic and prognostic accuracy. For example, a combination of CTCs and ctDNA analysis has been shown to improve the detection of early-stage CRC compared to either component alone.
Overall, the authors conclude that liquid biopsy components have the potential to be powerful predictive and prognostic biomarkers in CRC. However, further studies are needed to establish the clinical utility of these biomarkers and to determine the optimal strategies for their implementation in clinical practice.
This research was published in J Exp Clin Cancer Res. 2022 Mar 15;41(1):99. doi: 10.1186/s13046-022-02318-0.
