Cell-free DNA levels in plasma of patients with non-small-cell lung cancer and inflammatory lung disease

Abstract

Background:The analysis of plasma cell-free DNA (cfDNA) is expected to provide useful biomarkers for early diagnosis of non-small-cell lung cancer (NSCLC). However, it remains unclear whether the intense release of cfDNA into the bloodstream of NSCLC patients results from malignancy or chronic inflammatory response. Consequently, the current diagnostic utility of plasma cfDNA quantification has not been thoroughly validated in subjects with chronic respiratory inflammation. Here we assess the effect of chronic respiratory inflammation on plasma cfDNA levels and evaluate the potential clinical value of this phenomenon as an early lung cancer diagnostic tool.Methods:We measured plasma cfDNA concentrations in 50 resectable NSCLC patients, 101 patients with chronic respiratory inflammation (chronic obstructive pulmonary disease, sarcoidosis, or asthma) and 40 healthy volunteers using real-time PCR.Results:We found significantly higher plasma cfDNA levels in NSCLC patients than in subjects with chronic respiratory inflammation and healthy individuals (P<0.0001). There were no significant differences in plasma cfDNA levels between patients with chronic respiratory inflammation and healthy volunteers. The cutoff point of >2.8 ng ml−1 provided 90% sensitivity and 80.5% specificity in discriminating NSCLC from healthy individuals (area under the curve (AUC)=0.90). The receiver-operating characteristics curve distinguishing NSCLC patients from subjects with chronic respiratory inflammation indicated 56% sensitivity and 91% specificity at the >5.25-ng ml−1 cutoff (AUC=0.76).Conclusions:We demonstrated that elevated plasma cfDNA levels in NSCLC resulted primarily from tumour development rather than inflammatory response, raising the potential clinical implications for lung cancer screening and early diagnosis. Further research is necessary to better characterise and identify factors and processes regulating cfDNA levels in the blood under normal and pathological conditions.

Detection and prognostic value of recurrent exportin 1 mutations in tumor and cell-free circulating DNA of patients with classical Hodgkin lymphoma

“…In addition, it has been previously described that plasma cfDNA concentrations do not uniformly correlate with disease stage in solid tumors and biological mechanisms that underlined tumor cfDNA amount release are incompletely understood. 45,46 The results presented here are limited to patients with histologically confirmed cHL and may not be generalizable to HIV-associated HL, nodular lymphocyte-predominant HL or HL developing in the post-transplant setting. Finally, selective inhibitors of nuclear export (SINE), have been shown to effectively target XPO1 by retaining TSPs in the nucleus.…”

Development and Evaluation of a Duplex Real-Time PCR Assay With a Novel Internal Standard for Precise Quantification of Plasma DNA

“…There are various methods available for circulating cell-free DNA quantification, including real-time PCR [567891011121314151618212223242526], fluorescence spectrophotometry [4172023242528], ultraviolet spectrophotometry [22], capillary electrophoresis [2930], mass spectrometry [3031], surface plasmon resonance [3233], and electrochemical luminescence [34]. However, because DNA extraction inevitably leads to DNA loss, all of these methods have thus far been used for scientific research only and have not been applied in clinical laboratories.…”

“…Since Leon et al [2] discovered elevated levels of cell-free DNA in cancer patients in 1977, there has been great progress in cell-free DNA quantification research [3], and this emerging field has attracted much interest, resulting in reports on its numerous potential clinical applications for many pathologic conditions such as malignancy [4567891011], prenatal diseases [1213], trauma [1415], organ dysfunction [16], autoimmune diseases [17], and organ transplantation [18]. However, notable disagreements concerning the quantitative analysis of plasma DNA from a large number of laboratories have become a considerable pitfall, hampering its application in clinical laboratories [19].…”

Circulating tumor DNA (ctDNA) in the era of personalized cancer therapy

“…This is principally right in the case that in the peripheral blood circulation of GI cancers patients, the mutant form of Bdriver^genes and Bdrug-resistant^alleles of tumor are represented in the circulating cell-free tumor DNA (cfDNA) [95][96][97]. The discriminative accuracy of ctDNA the amount for diagnosis of gastrointestinal cancer contrast to the benign inflammatory diseaseshas been distinguished [98][99][100][101][102].In order to prove the comprehensive diagnostic value of ctDNA through diverse gastrointestinal tumor types, ctDNA of 640 patients evaluated by Bettegowda et al [53]. The NGS method used to find out target mutations of tumor tissue, and then by using RT-PCR quantified in ctDNA [53].…”