TABLE 2.
Representative studies relating cfDNA for clinical applications in gastrointestinal tract cancers.
| Study | Cancer type | Feature | Platform used | Summary |
|---|---|---|---|---|
| Hamfjord et al. (2019) | CRC | CfDNA quantification | ddPCR | High pretreatment cfDNA levels represented reduced DFS |
| Wu et al. (2021) | CRC | Methylation biomarkers in cfDNA | Targeted DNA methylation sequencing | Early-stage CRC and advanced adenomas (AAs) could be diagnosed by these 11 DNA methylation markers in cfDNA |
| Wu et al. (2022) | CRC | cfDNA quantification | qRT-PCR | Lowered cfDNA levels after chemotherapy |
| Represented better survival | ||||
| Walker et al. (2022) | CRC | Hydroxymethylcytosine-based classifier in cfDNA | Capturing 5hmC regions in cfDNA and sequencing on the Illumina platform | The classifier could detect early-stage I CRC and healthy patients with satisfactory sensitivity, which increased when other cfDNA parameters such as size and abundance were considered |
| Sai et al. (2007), Zhang et al. (2019a) | GC | cfDNA | qPCR | Elevated plasma cfDNA concentration and integrity were found in GC patients contrasting healthy individuals |
| Chen et al. (2023) | GC | CSF-cfDNA | Next-generation sequencing | Levels of cfDNA in CSF could indicate the presence of metastasis |
| Tokuhisa et al. (2007) | HCC | cfDNA | Real-time PCR | CfDNA levels were significantly associated with non-HCV-infected HCC patients and less with HCV-infected HCC patients |
| Yang et al. (2011) | HCC | cfDNA | Real-time fluorescent qPCR | hTERT DNA in cfDNA was more elevated in HCC patients than in HBV-infected HCC patients |
| Zheng et al. (2021a) | HCC | cfDNA | Circulating single-molecule amplification and resequencing technology (cSMART)-based method (SIM) | HBV-associated integrational hotspots to identify and segregate HCC patients with HBV-associated risks and progression |
| Kim et al. (2023) | HCC | cfDNA | Sensitive PCR-based method known as methylation sensitive high-resolution analysis (MS-HRM) | This methylation signature panel with RNF135 and LDHB could more accurately detect HCC patients from at-risk and healthy individuals |
| Zitt et al. (2008) | CRC | cfDNA | RT-PCR | Reduced post-CRT, cfDNA level represented a better response to CRT |
| Li et al. (2017a) | CRC | cfDNA | Copy number variation assessment | High CNVs associated with shorter survival |
| Zhong et al. (2020) | CRC | cfDNA | q-PCR | Post-surgical higher cfDNA concentration was associated with poor PFS |
CRC, colorectal cancer; GC, gastric cancer; HCC, hepatocellular carcinoma; PDAC, pancreatic ductal adenocarcinoma; CTCs, circulating tumor cells; EHM, extrahepatic metastasis; CNV, copy number variation; OS, overall survival; PFS, progression-free survival; DFS, disease-free survival.