The diagnostic value of circulating cell free DNA quantification in non-small cell lung cancer: A systematic review with meta-analysis

Different Liquid Biopsies for the Management of Non-Small Cell Lung Cancer in the Mutational Oncology Era

In the last ten years, liquid biopsy has been slowly joining the traditional invasive techniques for the diagnosis and monitoring of tumors. Liquid biopsies allow easy repeated sampling of blood, reflect the tumor scenario, and make personalized therapy real for the patient. Liquid biopsies isolate and utilize different substrates present in patients' body fluids such as circulating tumor cells, circulating tumor DNA, tumor extracellular vesicles, etc. One of the most-used solid cancers in the development of the non-invasive liquid biopsy approach that has benefited from scientific advances is non-small cell lung cancer (NSCLC). Using liquid biopsy, it is possible to have more details on NSCLC staging, progression, heterogeneity, gene mutations and clonal evolution, etc., basing the treatment on precision medicine as well as on the screening of markers for therapeutic resistance. With this review, the authors propose a complete and current overview of all different liquid biopsies available to date, to understand how much has been carried out and how much remains to be completed for a better characterization of NSCLC.

Clinical Potential of Circulating Cell-Free DNA (cfDNA) for Longitudinally Monitoring Clinical Outcomes in the First-Line Setting of Non-Small-Cell Lung Cancer (NSCLC): A Real-World Prospective Study

BACKGROUND

Despite the increasing implementation of targeted and immunotherapy-based treatments, the prognosis of patients with advanced NSCLC remains dismal. We prospectively evaluated longitudinal plasma cfDNA kinetics as an early marker of therapeutic efficacy in patients with advanced NSCLC undergoing standard first-line treatments.

METHODS

From February 2020 to May 2022, treatment-naïve patients with advanced NSCLC were consecutively enrolled at the Medical Oncology Unit of the Paolo Giaccone University Hospital, Palermo (Italy). We quantified cfDNA in terms of ng/μL using a Qubit^TM dsDNA HS Assay Kit. The agreement between the cfDNA and radiologic response was evaluated from baseline (T0) to the radiologic evaluation (T1).

RESULTS

A total of 315 liquid biopsy samples were collected from 63 patients at baseline, with a total of 235 paired plasma samples from 47 patients at disease re-evaluation. A fair concordance was observed between early and durable radiographic and cfDNA response (Cohen's kappa coefficient = 0.001); 11 and 18 patients receiving TKI (Pearson's chi-squared test = 4.278; Cohen's kappa coefficient = 0.039) and IO treatments (Pearson's chi-squared test = 7.481; Cohen's kappa coefficient = 0.006) showed a significant and durable association between cfDNA dynamics and the first radiologic evaluation, whereas among the 18 patients undergoing CT, no significant correlation was observed (Pearson's chi-squared test = 0.720; Cohen's kappa coefficient = 0.396). The ECOG-PS 2 patients presented with the mean baseline cfDNA levels 2.6-fold higher than those with ECOG-PS 0-1 (1.71 vs. 0.65 ng/µL; p = 0.105).

CONCLUSIONS

Our real-world study demonstrates that quantitative changes in cfDNA values correlated with responses to therapy and relapse of disease in treatment-naïve patients with advanced NSCLC undergoing TKI- and IO-based treatments.

Circulating Cell-Free DNA and DNA Integrity as Molecular Diagnostic Tools in Hepatocellular Carcinoma

OBJECTIVES

We assessed the ability to use circulating cell-free DNA (cfDNA) and the DNA integrity index (DNAII) to detect the transition from liver cirrhosis (LC) to hepatocellular carcinoma (HCC).

METHODS

Circulating cfDNA and DNAII were measured in 50 patients with advanced LC and 50 patients with HCC who were followed for 1 month after transarterial chemoembolization (TACE). Fifty healthy participants served as a control group. Real-time quantitative polymerase chain reaction (PCR) was used to measure circulating cfDNA concentration, and Alu-PCR was used to measure the concentration of Alu repeats, both short fragments (115 base pairs [bp]) and long fragments (247 bp). We compared liquid biopsy results with the relevant traditional markers.

RESULTS

The HCC group showed significantly higher circulating cfDNA concentrations and DNAII values compared with the LC and control groups. No significant differences were found in circulating cfDNA concentrations and DNAII values between the LC and control groups. Circulating cfDNA concentrations decreased significantly after treatment (TACE); areas under the curve of circulating cfDNA concentration and DNAII values were significantly better than those of ɑ-fetoprotein and vascular endothelial growth factor in discriminating between LC and HCC.

CONCLUSIONS

The combined use of DNAII with proteins induced by vitamin K absence or antagonist showed better diagnostic performance in HCC. Circulating cfDNA could have a potential role in monitoring HCC treatment.

Liquid biopsy as an option for predictive testing and prognosis in patients with lung cancer

BACKGROUND

The aim of this study was to investigate the clinical value of liquid biopsy as a primary source for variant analysis in lung cancer. In addition, we sought to characterize liquid biopsy variants and to correlate mutational load to clinical data.

METHODS

Circulating cell-free DNA was extracted from plasma from patients with lung cancer (n = 60) and controls with benign lung disease (n = 16). Variant analysis was performed using the AVENIO ctDNA Surveillance kit and the results were correlated to clinical and variant analysis data from tumor tissue or cytology retrieved from clinical routine diagnostics.

RESULTS

There were significantly more variants detected in lung cancer cases compared to controls (p = 0.011), but no difference between the histological subgroups of lung cancer was found (p = 0.465). Furthermore, significantly more variants were detected in patients with stage IIIb-IV disease compared to patients with stage I-IIIa (median 7 vs 4, p = 0.017). Plasma cfDNA mutational load was significantly associated with overall survival (p = 0.010). The association persisted when adjusted for stage and ECOG performance status (HR: 3.64, 95% CI 1.37-9.67, p = 0.009). Agreement between tumor and plasma samples significantly differed with stage; patients with stage IIIb-IV disease showed agreement in 88.2% of the cases with clinically relevant variants, compared to zero cases in stage I-IIIa (p = 0.004). Furthermore, one variant in EGFR, two in KRAS, and one in BRAF were detected in plasma but not in tumor samples.

CONCLUSION

This study concludes that in the vast majority of advanced NSCLC patients a reliable variant analysis can be performed using liquid biopsy from plasma. Furthermore, we found that the number of variants in plasma is associated with prognosis, possibly indicating a strategy for closer follow up on this crucial patient group.

Utility of Liquid Biopsy Analysis in Detection of Hepatocellular Carcinoma, Determination of Prognosis, and Disease Monitoring: A Systematic Review

BACKGROUND & AIMS

Liquid biopsies, or blood samples, can be analyzed to detect circulating tumor cells (CTCs), cell-free DNA (cfDNA), and extracellular vesicles, which might identify patients with hepatocellular carcinoma (HCC) or help determine their prognoses. We performed a systematic review of studies of analyses of liquid biopsies from patients with HCC and their comparisons with other biomarkers.

METHODS

We performed a systematic review of original studies published before December 1, 2019. We included studies that compared liquid biopsies alone and in combination with other biomarkers for the detection of HCC, performed multivariate analyses of the accuracy of liquid biopsy analysis in determining patient prognoses, or evaluated the utility of liquid biopsy analysis in monitoring treatment response.

RESULTS

Our final analysis included 112 studies: 67 on detection, 46 on determining prognosis, and 25 on treatment monitoring or selection. Ten studies evaluated assays that characterized cfDNA for detection of HCC in combination with measurement of α-fetoprotein (AFP)-these studies found that the combined measurement of cfDNA and AFP more accurately identified patients with HCC than measurement of AFP alone. Six studies evaluated assays for extracellular vesicles and 2 studies evaluated assays for CTC in detection of HCC, with and without other biomarkers-most of these studies found that detection of CTCs or extracellular vesicles with AFP more accurately identified patients with HCC than measurement of AFP alone. Detection of CTCs before surgery was associated with HCC recurrence after resection in 13 of 14 studies; cfDNA and extracellular vesicles have been studied less frequently as prognostic factors. Changes in CTC numbers before vs after treatment more accurately identify patients with HCC recurrence than pretreatment counts alone, and measurements of cfDNA can identify patients with disease recurrence or progression before changes can be detected by imaging. We found little evidence that analyses of liquid biopsies can aid in the selection of treatment for HCC. Quality assessment showed risk of bias in studies of HCC detection and determination of prognosis.

CONCLUSIONS

In a systematic review of 112 studies of the accuracy of liquid biopsy analysis, we found that assays for CTCs and cfDNA might aid in determining patient prognoses and monitoring HCC, and assays for cfDNA might aid in HCC detection, but there is a risk of bias in these studies. Studies must be standardized before we can assess the clinical utility of liquid biopsy analysis in the detection and management of patients with HCC.

Circulating cell-free DNA as a diagnostic and prognostic biomarker for non-small-cell lung cancer: a systematic review and meta-analysis

Aim: A meta-analysis was conducted to assess the application of circulating cell-free DNA (cfDNA) in non-small-cell lung carcinoma (NSCLC) screening, EGFR and KRAS mutation detection. Materials & methods: A comprehensive literature search was conducted. The summary sensitivity and specificity for cfDNA in NSCLC diagnosis, EGFR and KRAS mutation detection were calculated. Results: The sensitivity and specificity for NSCLC diagnosis, EGFR and KRAS mutation detection were 0.80 (95% CI: 0.72-0.87) and 0.81 (95% CI: 0.68-0.91), 0.780 (95% CI: 0.711-0.853) and 0.962 (95% CI: 0.942-0.984), 0.628 (95% CI: 0.244-0.919) and 0.959 (95% CI: 0.932-0.998), respectively. Conclusion: cfDNA was a minimally invasive approach for NSCLC diagnosis, but its clinical utility warranted more future investigations because of the suboptimal sensitivity.

Progress in quantitative technique of circulating cell free DNA and its role in cancer diagnosis and prognosis

The interest in the potential application value of circulating cell free DNA (ccfDNA) has increased rapidly in recent years, as numerous researchers have demonstrated that the change of its level in the blood is associated with many diseases. Its potential role in cancer management is of particular concern. In comparison with traditional invasive tissue biopsy, quantitative analysis of ccfDNA level for the detection of cancer is advantageous due to the non-invasiveness of blood collection. Moreover, its clinical significance in prognosis prediction and dynamic monitoring of disease progression in cancer patients is equally worthy of attention. At the same time, quantitative detection of ccfDNA is being improved to pursue higher sensitivity due to its low concentration in the blood sample. In this review, we will summarize the progress in quantitative technology of ccfDNA and describe the possible relationship between ccfDNA level and cancer diagnosis and prognosis prediction.

Liquid biopsy for non-invasive assessment of liver injury in hepatitis B patients

BACKGROUND

Hepatitis B is a major public health problem in China. Accurate liver injury assessment is essential for clinical evidence-based treatment. Liver biopsy is considered the gold standard method to stage liver disease, but it is not widely used in resource-limited settings. Therefore, non-invasive liquid biopsy tests are needed.

AIM

To assess liver injury in hepatitis B patients using quantified cell free DNA combined with other serum biomarker as a liquid biopsy-based method.

METHODS

A cohort of 663 subjects including 313 hepatitis B patients and 350 healthy controls were enrolled. Ultrasound-guided liver biopsies followed by histopathological assessments were performed for the 263 chronic hepatitis B patients to determine the degree of liver injury. Cell-free DNA was quantified using a novel duplex real-time polymerase chain reaction assay.

RESULTS

Compared with healthy controls, patients with hepatitis B virus (HBV) infection had significantly higher plasma DNA, serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), bilirubin, and HBV DNA levels (P < 0.01). Serum ALT, AST, bilirubin, and plasma DNA levels of patients with marked-severe inflammation were significantly higher than those with mild-moderate inflammation (P < 0.01). There was a statistically significant correlation between hepatocyte inflammation severity and serum bilirubin (R² = 0.673, P < 0.01) or plasma DNA (R² = 0.597, P < 0.01) levels. The areas under the curves of serum ALT, bilirubin, plasma DNA, and their combination to distinguish between patients with mild–moderate and marked-severe inflammation were 0.8059, 0.7910, 0.7921, and 0.9564, respectively.

CONCLUSION

The combination of plasma DNA, serum ALT, and bilirubin could be a candidate liquid biopsy for non-invasive assessment of liver injury in hepatitis B patients.

Comprehensive Evaluation of the Factors Affecting Plasma Circulating Cell-Free DNA Levels and Their Application in Diagnosing Nonsmall Cell Lung Cancer

AIMS

Circulating cell-free DNA (ccfDNA) is a valuable biomarker, but the ccfDNA levels are influenced by variations that occur during sample processing. The feasibility of using ccfDNA as a diagnostic biomarker requires further examination.

MATERIALS AND METHODS

We established a real-time PCR assay with an external standard to comprehensively evaluate the factors affecting ccfDNA levels, including the extraction kit used, freeze-thaw stability, and stability of delayed extraction. Then we compared the ccfDNA levels between benign controls (64 cases, including 23 sarcoidosis patients, 19 pneumonia patients, and 22 other lung disease patients) and nonsmall cell lung cancer (NSCLC) patients (74 patients).

RESULTS

The different kits showed different recovery rates. Moreover, the ccfDNA present in plasma or stored in extraction buffer was stable after freeze-thawing, and the ccfDNA concentration remained consistent for 24 h at 4°C and for 12 h at room temperature. The patients with NSCLC-III/IV exhibited significantly higher ccfDNA levels than the patients with NSCLC-I/II (293 copies/μL vs. 190 copies/μL, p = 0.0339). However, no significant differences in the plasma ccfDNA levels were observed between the benign controls and NSCLC patients (241 copies/μL vs. 233 copies/μL, p > 0.05).

CONCLUSIONS

Variations in sample processing procedures led to variable results. The lack of differences between the NSCLC patients and benign controls indicates that further research is necessary to better characterize ccfDNA as a biomarker for diagnosing NSCLC.

Maternal Malignancy Evaluation After Discordant Cell-Free DNA Results

Cell-free DNA screening for fetal aneuploidy is a commonly used testing strategy in pregnancies at high risk for fetal aneuploidy. The use of cell-free DNA screening is expanding to the low-risk population, because the detection rate for trisomy 21 surpasses that of traditional screening modalities. Although the sensitivity and specificity of cell-free DNA are superior to traditional screening, false-positive results do occur and may indicate an adverse maternal health condition, including maternal mosaicism or, rarely, malignancy. The risk of maternal cancer is significantly elevated when more than one aneuploidy is detected that is discordant from fetal karyotype. Given this risk as well as the rising incidence of cancer in pregnancy, patient counseling and malignancy evaluation should be considered in women when more than one aneuploidy is detected. We reviewed the published literature and developed an algorithm to evaluate women when these results are identified.

Whole Exome Sequencing of Cell-Free DNA for Early Lung Cancer: A Pilot Study to Differentiate Benign From Malignant CT-Detected Pulmonary Lesions

Introduction: Indeterminate pulmonary lesions (IPL) detected by CT pose a significant clinical challenge, frequently necessitating long-term surveillance or biopsy for diagnosis. In this pilot investigation, we performed whole exome sequencing (WES) of plasma cell free (cfDNA) and matched germline DNA in patients with CT-detected pulmonary lesions to determine the feasibility of somatic cfDNA mutations to differentiate benign from malignant pulmonary nodules. Methods: 33 patients with a CT-detected pulmonary lesions were retrospectively enrolled (n = 16 with a benign nodule, n = 17 with a malignant nodule). Following isolation and amplification of plasma cfDNA and matched peripheral blood mononuclear cells (PBMC) from patient blood samples, WES of cfDNA and PBMC DNA was performed. After genomic alignment and filtering, we looked for lung-cancer associated driver mutations and next identified high-confidence somatic variants in both groups. Results: Somatic cfDNA mutations were observed in both groups, with the cancer group demonstrating more variants than the benign group (1083 ± 476 versus 553 ± 519, p < 0.0046). By selecting variants present in >2 cancer patients and not the benign group, we accurately identified 82% (14/17) of cancer patients. Conclusions: This study suggests a potential role for cfDNA for the early identification of lung cancer in patients with CT-detected pulmonary lesions. Importantly, a substantial number of somatic variants in healthy patients with benign pulmonary nodules were also found. Such "benign" variants, while largely unexplored to date, have widespread relevance to all liquid biopsies if cfDNA is to be used accurately for cancer detection.

Cell-free DNA diagnostics: current and emerging applications in oncology

Liquid biopsy is a noninvasive dynamic approach for monitoring disease over time. It offers advantages including limited risks of blood sampling, opportunity for more frequent sampling, lower costs and theoretically non-biased sampling compared with tissue biopsy. There is a high degree of concordance between circulating tumor DNA mutations versus primary tumor mutations. Remote sampling of circulating tumor DNA can serve as viable option in clinical diagnostics. Here, we discuss the progress toward broad adoption of liquid biopsy as a diagnostic tool and discuss knowledge gaps that remain to be addressed.

Diagnostic Value of Concentration of Circulating Cell-Free DNA in Breast Cancer: A Meta-Analysis

The diagnostic value of the concentration of circulating cell-free DNA (cfDNA) for breast cancer has generated inconsistent results. The aim of this study was to evaluate the first diagnostic value of the concentration of cfDNA for breast cancer by meta-analysis. Studies were retrieved by searching PubMed, Cochrane Library, and Web of Science before June 2018. Sensitivity, specificity, diagnostic odds ratio (DOR), the summary receiver operating characteristic (SROC) curve, and the area under curve (AUC) were used to summarize overall diagnostic performance. The random-effects model was used to calculate the pooled statistics. Subgroup analysis and meta-regression analysis were carried out to detect the source of heterogeneity. A total of 13 studies were identified with 1,087 breast cancer patients and 720 healthy controls. Overall, the pooled sensitivity and specificity of concentration of cfDNA for breast cancer were 87% (95% CI, 73–94%) and 87% (95% CI, 79–93%), respectively. The pooled DOR was 32.93 (95% CI, 13.52–80.19) and the SROC curve revealed an AUC of 0.93 (95% CI, 0.91–0.95). Meta-regression analysis showed that no covariate had a significant correlation with relative DOR (RDOR). Publication bias was not detected in this meta-analysis. This meta-analysis indicates that the concentration of cfDNA has potential first diagnostic value for breast cancer and plasma may be a better source of cfDNA for detection of breast cancer.

La biopsie liquide

La biopsie liquide est apparue comme une voie prometteuse pour le dépistage du cancer. En effet, plusieurs biomarqueurs comme les ADN circulants, les cellules tumorales circulantes, les micro-ARN circulants etc. se sont révélés prometteurs pour le théragnostic ou le suivi du patient. La détection précoce peut aider à réduire la mortalité associée au cancer et augmenter la survie globale des patients. La plupart des types de cancer manquent de biomarqueurs spécifiques et le développement de techniques de dépistage efficaces appliquées en clinique a été limité malgré des efforts intenses dans ce domaine. La nature non invasive de la biopsie liquide lui donne un avantage vis-à-vis d’autres méthodes, notamment pour le développement de tests de dépistage du cancer. Les différentes études fondées sur l’analyse de la biopsie liquide dans le but de développer des tests de dépistage et de détection précoce du cancer sont présentées dans cette revue. Bien qu’actuellement aucun test développé à partir de la biopsie liquide s’avère à la fois assez spécifique et sensible pour être utilisé comme test universel de dépistage, le potentiel de cette nouvelle approche apparaît de plus en plus crédible, eu égard aux récents développements de méthodes sophistiquées, notamment multiparamétriques.

Kaempferol suppresses proliferation but increases apoptosis and autophagy by up-regulating microRNA-340 in human lung cancer cells

BACKGROUND

Lung cancer is a leading cause of cancer-related deaths worldwide with unsatisfied prognosis. Kaempferol is a dietary flavonoid that inhibits tumorgenesis, and we aimed to uncover the underlying mechanism of kaempferol in lung cancer cells.

METHODS

A549 cells were stimulated with kaempferol, and then cell proliferation, apoptosis, autophagy and expression of miR-340 were assessed. Subsequently, effects of kaempferol on protein expression of phosphatase with tensin homology (PTEN) and key kinases in the phosphatidylinositol-3-kinase (PI3K)/AKT pathways were detected by Western blot analysis. Moreover, the effects of miR-340 inhibition on kaempferol-induced alterations in A549 cells were also studied.

RESULTS

Cell viability, proliferation and cyclinD1 expression level in A549 cells were all reduced by kaempferol. Conversely, cell apoptosis and autophagy were promoted by kaempferol. We found autophagy promoted apoptosis in kaempferol-treated A549 cells. Then, expression of miR-340 was identified to be up-regulated by kaempferol treatment. After treatments with kaempferol, PTEN level was elevated and levels of p-PI3K and p-AKT were decreased. Moreover, the alterations induced by kaempferol were abrogated by miR-340 inhibition.

CONCLUSION

Kaempferol inhibited proliferation but induced apoptosis and autophagy in A549 cells. Additionally, kaempferol might function through up-regulating miR-340, along with up-regulation of PTEN and inactivation of the PI3K/AKT pathway.

A quantitative analysis of the potential biomarkers of non-small cell lung cancer by circulating cell-free DNA

The study was conducted to ascertain whether the quantification of circulating cell-free DNA (cfDNA) in serum has value as a diagnostic or for monitoring the progression of non-small cell lung cancer (NSCLC). The serum/plasma cfDNA concentration was quantified by absolute qPCR of long interspersed nuclear element-1 (LINE1) in 60 NSCLC patients and 68 controls in good health. Receiver operating characteristic (ROC) curve analysis was performed to determine the diagnostic utility and cut-off levels of cfDNA, CEA, and CYFRA21-1 in NSCLC patients. Correlations between cfDNA and age, sex, tumour stage and progression-free survival (PFS) were analysed. A follow-up study was conducted on 4 NSCLC patients, and serum cfDNA, CEA, and CYFRA21-1 were quantified throughout disease progression. Serum cfDNA levels were significantly higher in NSCLC patients than those in normal controls. Elevated serum cfDNA concentration was also significantly associated with advanced tumour stage. Serum cfDNA had a ROC area under the curve comparable to that of CEA and CYFRA21-1 for the diagnosis of NSCLC, and the combined cfDNA/CEA/CYFRA21-1 indicator had the highest diagnostic efficiency. Moreover, increased serum cfDNA levels were strongly correlated with tumour progression and poor PFS. This study preliminarily confirmed that cfDNA can monitor disease progression in NSCLC patients, and the lead time was 1–7 months compared with clinical medical imaging. Serum cfDNA may be useful in monitoring NSCLC progression, suggesting that the non-invasive quantification of serum cfDNA by LINE1 qPCR is a viable option for predicting progression and disease severity when repeated invasive tissue biopsy is not possible.

Tumor necrosis factor-related apoptosis-inducing ligand additive with Iodine-131 of inhibits non-small cell lung cancer cells through promoting apoptosis

Non-small-cell lung cancer (NSCLC) accounts for ~80% of human lung cancer cases and is the most common cause of cancer-associated mortality worldwide. Reports have indicated that tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and Iodine-131 (I-131) can induce tumor cell apoptosis. The purpose of the present study was to investigate the additive efficacy of TRAIL and I-131 on NSCLC cells. The present study demonstrated that additive treatment of TRAIL and I-131 (TRAIL-I-131) significantly inhibited the growth and aggressiveness of NSCLC cells compared with single TRAIL or I-131 treatment. Results demonstrated that TRAIL-I-131 treatment induced apoptosis of NSCLC cells, with western blot analysis confirming that TRAIL-I-131 treatment increased proapoptotic Bad and Bax expression levels, while antiapoptotic Bcl-2 and Bcl-w protein levels were decreased in NSCLC cells. The present study demonstrated that TRAIL-I-131 treatment inhibited vascular endothelial growth factor (VEGF) and activator protein-1 (AP-1) in NSCLC cells. Potential mechanism analyses identified that TRAIL-I-131 treatment induced apoptosis of NSCLC cells through caspase-9 activation. In vivo assays revealed that TRAIL-I-131 treatment significantly inhibited NSCLC tumor growth and increased apoptotic bodies in tumor tissues. Immunohistology demonstrated that caspase-9 was upregulated and VEGF was downregulated in tumor tissues in TRAIL-I-131-treated tumors. In conclusion, these results indicate that TRAIL combined with I-131 promoted apoptosis of NSCLC through caspase-9 activation, which may be a promising anticancer therapeutic schedule for the treatment of NSCLC.

Quantitation of cell-free DNA in blood is a potential screening and diagnostic maker of breast cancer: a meta-analysis

INTRODUCTION

Increased cell-free DNA (cfDNA) levels in circulating blood have been associated with higher possibility of breast cancer, however, researchers have not reached an agreement on its analysis.

MATERIALS AND METHODS

We conducted a meta-analysis of 12 retrospective studies to clarify the value of cfDNA quantification in screening and diagnosis of breast cancer. PubMed, EMBASE, Web of Science and Cochrane library were searched from January, 2000 to October, 2016. Pooled analyses were estimated using a random effects model.

RESULTS

In total, 1003 primary breast cancer patients, 283 cases with benign breast disease and 575 healthy individuals were included. Pooled diagnostic odds ratio (DOR) was 27.63 (95% confidence interval [CI]: 10.96~69.61, I2 = 86.2%, P < 0.001) in discriminating between breast cancer and healthy controls; the area under the summary receiver operating characteristic (SROC) curve measured 0.91 (95% CI: 0.17~1.00). Analysis of available data in distinguishing breast cancer and benign breast disease showed a pooled DOR of 35.30 (95% CI: 7.58~164.39, I2 = 79.9%, P = 0.002) with an area under SROC of 0.91 (95% CI: 0.89~0.93). Ethnic group distribution based geographical factors suggested by meta-regression and subgroup analyses explained most of the heterogeneity.

CONCLUSIONS

Quantification of cfDNA is a promising test in screening and diagnostic of breast cancer, but population-based standardization of test methods require completion prior to clinical use.

Liquid biopsy in non-small cell lung cancer: a key role in the future of personalized medicine?

INTRODUCTION

Liquid biopsies, especially the analysis of circulating tumor DNA (ctDNA), as a novel and non-invasive method for the diagnosis and monitoring of non-small cell lung cancer (NSCLC) have already been implemented in clinical settings. The majority of ctDNA is released from apoptotic or necrotic tumor cells, thus reflecting the genetic profile of a tumor. Numerous studies have reported a high concordance in mutation profiles derived from liquid biopsy and tissue biopsy, especially in driver genes. Liquid biopsy could overcome the clonal heterogeneity of tumour biopsy, as it provides a single snapshot of a tumour tissue. Moreover, non-invasiveness is the biggest advantage for liquid biopsy, and the procedure can be repeatedly performed during the treatment for the purpose of monitoring. Therefore, ctDNA could act as a potential complementary method for tissue biopsies in diagnosis, prognostic, treatment response and resistance. Areas covered: This review summarizes the recent advancements in liquid biopsy with a focus on NSCLC, including its applications and technologies associated with assessing ctDNA. The authors conclude the review by discussing the challenges associated with liquid biopsy. Expert commentary: The analysis of ctDNA represents a promising method for liquid biopsy, which will be a novel and potentially complementary method in diagnosis, treatment and prognostic in NSCLC at all stages.

Plasma cell-free DNA level and its integrity as biomarkers to distinguish non-small cell lung cancer from tuberculosis

AIMS

The aim of this study was to evaluate the potential clinical value of the plasma cell-free DNA (cfDNA) concentrations and strand integrity as an auxiliary tool for Non-small cell lung cancer (NSCLC) differential diagnosis from tuberculosis in patients with solitary pulmonary nodules detected by computed tomography (CT).

METHODS

This research was divided into 3 groups: NSCLC (n=106), tuberculosis (n=105) and healthy controls (n=107). The quantization of plasma DNA fragments was performed by quantitative real-time PCR. Amplifying and quantifying shorter (115bp) and longer (247bp) fragments from abundant genomic ALU repeats.

RESULTS

The level of cfDNA (ALU115) in patients with NSCLC [95.67 (51.28, 238.85) ng/μl] was significantly higher than that in patients with tuberculosis [59.60 (34.25, 102.53) ng/μl, P=0.001] and that in healthy controls [44.66 (24.56, 66.54) ng/μl, P=0.001]. The integrity of cfDNA in patients with NSCLC [5.91(4.14, 7.45)] was also significantly higher than that in patients with tuberculosis [3.85 (2.91, 5.06), P=0.000] and that in healthy controls [2.78(2.18, 4.82), P=0.000]. Receiver-operating characteristic (ROC) curve analysis showed that cfDNA(ALU115) and its integrity could be used as biomarkers to distinguish NSCLC from tuberculosis (AUC=0.628, P=0.001, cut-off values=91.48, sensitivity=57.50%, specificity=64.80%; AUC=0.722, P=0.000, cut-off values=5.54, sensitivity=55.70%, specificity=82.90%, respectively). In addition, the effect of integrity of cfDNA(AUC=0.722) to distinguish NSCLC from tuberculosis was higher than traditional tumor marker Carbohydrate antigen 125(CA125) (AUC=0.626), Neuron-specific enolase(NSE) (AUC=0.716) and Carcino-embryonic antigen(CEA) (AUC=0.589).

CONCLUSIONS

cfDNA and its integrity could be used as indicators for identification of NSCLC from tuberculosis. Moreover, the effect of integrity of cfDNA to distinguish NSCLC from tuberculosis was higher than traditional tumor marker CA125, NSE and CEA.

Mutational Landscape of cfDNA Identifies Distinct Molecular Features Associated With Therapeutic Response to First-Line Platinum-Based Doublet Chemotherapy in Patients with Advanced NSCLC

Rationale To investigate whether the mutational landscape of circulating cell-free DNA (cfDNA) could predict and dynamically monitor the response to first-line platinum-based chemotherapy in patients with advanced non-small-cell lung cancer (NSCLC). Methods Eligible patients were included and blood samples were collected from a phase III trial. Both cfDNA fragments and fragmented genomic DNA were extracted for enrichment in a 1.15M size panel covering exon regions of 1,086 genes. Molecular mutational burden (MMB) was calculated to investigate the relationship between molecular features of cfDNA and response to chemotherapy. Results In total, 52 eligible cases were enrolled and their blood samples were prospectively collected at baseline, every cycle of chemotherapy and time of disease progression. At baseline, alterations of 17 genes were found. Patients with partial response (PR) had significantly lower baseline MMB of these genes than those patients with either stable disease (SD) (P = 0.0006) or progression disease (PD) (P = 0.0074). Further analysis revealed that the mutational landscape of cfDNA from pretreatment blood samples were distinctly different among patients with PR vs. SD/PD. For patients with baseline TP53 mutation, those with PR experienced a significant reduction in MMB whereas patients with SD or PD experienced an increase after two, three or four cycles of chemotherapy. Furthermore, patients with low MMB had superior response rate and significantly longer progression-free survival than those with high MMB. Conclusion This study indicated that the mutational landscape of cfDNA has potential clinical value to predict the therapeutic response to first-line platinum-based doublet chemotherapy in NSCLC patients. At the single gene level, dynamic change of molecular mutational burden of TP53 is valuable to monitor efficacy (and, therefore, might aid in early recognition of resistance and relapse) in patients harboring this mutation at baseline.

Quantification of circulating cell-free DNA to predict patient survival in non-small-cell lung cancer

We used computed tomography (CT) to explore the prognostic value of cell-free (cf) DNA quantification and its predictive efficacy over time after chemotherapy in non-small-cell lung cancer (NSCLC) patients. In total, 177 NSCLC patients were enrolled in a prospective biomarker trial. Consecutive paired blood collection was performed to determine cfDNA concentrations at baseline CT and throughout serial follow-ups. The best cfDNA cut-off value to predict progression-free and overall survival was determined using X-tile analysis. Among 112 chemo-naive patients with stage IV adenocarcinoma, 43 were available for follow-up analysis. Cox regression multivariate analysis indicated that a high cfDNA concentration was an independent negative prognostic factor for progression-free survival (hazard ratio: 2.60; 95% confidence interval: 1.65-4.10; p = 0.008) and overall survival (hazard ratio: 2.63; 95% confidence interval: 1.66-4.17; p < 0.001). However, cfDNA concentration changes during treatment did not correlate with radiological CT responses at first follow-up or best response. No pattern was noted in the percent change in the cfDNA concentration from baseline or subsequently measured level to progression. The serum cfDNA concentration is thus associated with NSCLC patient prognosis, but does not appear to be a clinically valid marker for tumor responses.

SUVmax and Tumour Location in PET-CT Predict Oncogene Status in Lung Cancer

BACKGROUND

In non-small cell lung cancer, anaplastic lymphoma kinase gene rearrangement (ALK+) and epidermal growth factor receptor mutations (EGFR+) are targetable with tyrosine kinase inhibitors.

PATIENTS AND METHODS

27 patients with ALK+ tumours, who underwent positron emission tomography-computed tomography (PET-CT) prior to any treatment, were identified. 2 equally sized control groups based on consecutive patients with EGFR+ and EGFR/ALK wild-type (wt) were identified. The maximum standardized uptake value (SUVmax), tumour location (central vs. peripheral), as well as patient- and disease-specific characteristics were collected.

RESULTS

Mutation status was significantly associated with SUVmax (p < 0.008). The median SUVmax of the primary tumour in the lung for ALK+ patients (SUVmax 13) was significantly higher compared to that of the EGFR+ (SUVmax 9.8, p = 0.010) and the EGFR/ALKwt group (SUVmax 9.6, p = 0.022). No difference was observed between the EGFR+ and the EGFR/ALKwt group (p = 0.961). Mutation status was also associated with primary tumour location (p = 0.001). There was a significantly lower rate of central tumours in the EGFR+ group when compared to ALK+ tumours (15%, p = 0.002). Among EGFR/ALKwt tumours, 41% were central compared to 63% of ALK+ tumours (p = 0.235).

CONCLUSION

On initial PET-CT, ALK+ primary lung tumours showed a higher SUVmax and were more frequently centrally located while peripheral tumours were more likely to be EGFR+.