KEY TAKEAWAYS
- The study aimed to evaluate the potential of DII as a diagnostic and prognostic biomarker in pts with NSCLC.
- The cfDNA and DII represent a promising early prognostic tool.
Analysis of free DNA molecules shed from tumour cells in the plasma of patients (pts), referred to as circulating tumour DNA (ctDNA), in contrast to physiological circulating cell-free DNA (cfDNA), is nowadays exploited as liquid biopsy, a new emerging promising biomarker for diagnosis which assists in selection of proper treatment, and prognosis of cancer.
DNA integrity index (DII) is assessed by calculating the ratio between the concentration of long cfDNA strands released from tumour cells (ALU247) and the short strands released from normal cells (ALU115).
Nada Ezzeldin and the team determined to assess the DII, evaluated by the ratio of long to short cfDNA strands, as a potential diagnostic and prognostic biomarker for non-small cell lung cancer (NSCLC).
Researchers selected 48 NSCLC pts diagnosed with primary NSCLC before treatment initiation. About 30 COPD pts diagnosed clinically and radiologically, and subjected to chest high-resolution computerized tomography (CT), along with 40 healthy controls, were included. The cfDNA concentration and DII were measured using quantitative real-time polymerase chain reaction (qPCR).
The ALU115, ALU247, and DII levels were found to be significantly higher in NSCLC pts compared to both COPD pts (P< 0.0001) and healthy controls (P< 0.0001), and also higher in COPD pts compared to controls (P< 0.0001).
Furthermore, DII showed positive correlations with the stage of the tumour (P= 0.01), presence of tumour metastasis (P= 0.004), and adenocarcinoma histopathological subtype compared to other types (P= 0.02).
In evaluating the clinical utility of DII in NSCLC, ROC curve analysis revealed an area under the curve (AUC) of 0.91 at a cut-off value of 0.44, demonstrating overall accuracy of 85.6%, sensitivity of 90%, specificity of 83%, positive predictive value (PPV) of 78.1%, and negative predictive value (NPV) of 92.1%.
The study concluded that cfDNA and DII offer a promising noninvasive tool for the diagnosis and prognosis of NSCLC, demonstrating potential in screening, early detection, and disease monitoring.
The study was funded by the National Research Centre (NRC), Cairo, Egypt.
Source: https://pubmed.ncbi.nlm.nih.gov/38880832/
Ezzeldin N., El-Lebedy D., Hassan M., et al. (2024). “Evaluating circulating cell-free DNA and DNA integrity index as biomarkers in non-small cell lung cancer.” J Egypt Natl Canc Inst. 2024 Jun 17;36(1):21. doi: 10.1186/s43046-024-00219-1. PMID: 38880832.
