Characterisation of dysplastic liver nodules using low-pass DNA sequencing and detection of chromosome arm-level abnormalities in blood-derived cell-free DNA

Monitoring Hepatocellular Carcinoma Using Tumor Content in Circulating Cell-Free DNA

PURPOSE

The objective of the study was to evaluate the use of tumor content in circulating cell-free DNA (ccfDNA) for monitoring hepatocellular carcinoma (HCC) throughout its natural history.

EXPERIMENTAL DESIGN

We included 67 patients with hepatitis B virus-related HCC, of whom 17 had paired pre- and posttreatment samples, and 90 controls. Additionally, in a prospective cohort with hepatitis B virus surface antigen-positive participants recruited in 2012 and followed up biannually with blood sample collections until 2019, we included 270 repeated samples before diagnosis from 63 participants who later developed HCC (pre-HCC samples). Shallow whole-genome sequencing and the ichorCNA method were used to analyze genome-wide copy number and tumor content in ccfDNA.

RESULTS

High tumor content was associated with advanced tumor stage (P < 0.001) and poor survival after HCC diagnosis [HR = 12.35; 95% confidence interval (CI) = 1.413-107.9; P = 0.023]. Tumor content turned negative after surgery (P = 0.027), whereas it remained positive after transarterial chemoembolization treatment (P = 0.578). In non-HCC samples, the mean tumor content (±SD) was 0.011 (±0.007) and had a specificity of 97.8% (95% CI = 92.2%-99.7%). In pre-HCC samples, the tumor content increased from 0.014 at 4 years before diagnosis to 0.026 at 1 year before diagnosis. The sensitivity of tumor content in detecting HCC increased from 22.7% (95% CI = 11.5%-37.8%) within 1 year before diagnosis to 30.4% (95% CI = 13.2%-52.9%) at the Barcelona Clinic Liver Cancer (BCLC) stage 0/A, 81.8% (95% CI = 59.7%-94.8%) at stage B, and 95.5% (95% CI = 77.2%-99.9%) at stage C.

CONCLUSIONS

The tumor content in ccfDNA is correlated with tumor burden and may help in monitoring HCC 1 yearearlier than clinical diagnosis and in predicting patient prognosis.

Liquid Liver Biopsy for Disease Diagnosis and Prognosis

Liver diseases are a major burden worldwide, the scope of which is expected to further grow in the upcoming years. Clinically relevant liver dysfunction-related blood markers such as alanine aminotransferase and aspartate aminotransferase have limited accuracy. Nowadays, liver biopsy remains the gold standard for several liver-related pathologies, posing a risk of complication due to its invasive nature. Liquid biopsy is a minimally invasive approach, which has shown substantial potential in the diagnosis, prognosis, and monitoring of liver diseases by detecting disease-associated particles such as proteins and RNA molecules in biological fluids. Histones are the core components of the nucleosomes, regulating essential cellular processes, including gene expression and DNA repair. Following cell death or activation of immune cells, histones are released in the extracellular space and can be detected in circulation. Histones are stable in circulation, have a long half-life, and retain their post-translational modifications. Here, we provide an overview of the current research on histone-mediated liquid biopsy methods for liver diseases, with a focus on the most common detection methods.

Current Concepts of Precancerous Lesions of Hepatocellular Carcinoma: Recent Progress in Diagnosis

The most common cause of hepatocellular carcinoma (HCC) is chronic hepatitis and cirrhosis. It is proposed that precancerous lesions of HCC include all stages of the disease, from dysplastic foci (DF), and dysplastic nodule (DN), to early HCC (eHCC) and progressed HCC (pHCC), which is a complex multi-step process. Accurately identifying precancerous hepatocellular lesions can significantly impact the early detection and treatment of HCC. The changes in high-grade dysplastic nodules (HGDN) were similar to those seen in HCC, and the risk of malignant transformation significantly increased. Nevertheless, it is challenging to diagnose precancerous lesions of HCC. We integrated the literature and combined imaging, pathology, laboratory, and other relevant examinations to improve the accuracy of the diagnosis of precancerous lesions.

The current status of cell‐free human papillomavirus DNA as a biomarker in cervical cancer and other HPV ‐associated tumors: A review

Tumor cells release fragments of their DNA into the circulation, so called cell-free tumor DNA (ctDNA), allowing for analysis of tumor DNA in a simple blood test, that is, liquid biopsy. Cervical cancer is one of the most common malignancies among women worldwide and high-risk human papillomavirus (HR-HPV) is the cause of the majority of cases. HR-HPV integrates into the host genome and is often present in multiple copies per cell and should thus also be released as ctDNA. Such ctHPV DNA is therefore a possible biomarker in cervical cancer. In this review, we first give a background on ctDNA in general and then a comprehensive review of studies on ctHPV DNA in cervical cancer and pre-malignant lesions that may develop in cervical cancer. Furthermore, studies on ctHPV DNA in other HPV related malignancies (eg, head-and-neck and anogenital cancers) are briefly reviewed. We conclude that detection of ctHPV DNA in plasma from patients with cervical cancer is feasible, although optimized protocols and ultra-sensitive techniques are required for sufficient sensitivity. Results from retrospective studies in both cervical cancer and other HPV-related malignancies suggests that ctHPV DNA is a promising prognostic biomarker, for example, for detecting relapses early. This paves the way for larger, preferably prospective studies investigating the clinical value of ctHPV DNA as a biomarker in cervical cancer. However, there are conflicting results whether ctHPV DNA can be found in blood from patients with pre-malignant lesions and further studies are needed to fully elucidate this question.