Circulating free DNA in plasma or serum as biomarkers of carcinogenesis in colon cancer

The Impact of potential 'confounders' on the diagnostic sensitivity of circulating free DNA in management of FIT+ patients: a pilot study

Cell-free DNA (cfDNA) has long been established as a useful diagnostic and prognostic tool in a variety of clinical settings, ranging from infectious to cardiovascular and neoplastic diseases. However, non-neoplastic diseases can act as confounders impacting on the amount of cfDNA shed in bloodstream and on technical feasibility of tumour derived free circulating nucleic acids selecting patients with cancer. Here, we investigated the potential impact of other pathological processes in the clinical stratification of 637 FIT+ patients. A single and multiple logistic regression yielded similar results. Crude sensitivity was 75.9% versus adjusted sensitivity of 74.1%, relative risk 0.9761 (0.8516 to 1.1188), risk difference 0.0181 (-0.0835 to 0.1199) and OR 0.9079 (0.5264 to 1.5658). Potential confounding effect from other source of cfDNA plays a pivotal role in the clinical stratification of FIT+ patients.

Diagnostic performance of various liquid biopsy methods in detecting colorectal cancer: A meta-analysis

Liquid biopsy is a promising method in detecting colorectal cancer (CRC). However, previous meta‐analyses only focused on the diagnostic performance of cell‐free DNA (cfDNA). Therefore, we firstly evaluated the overall performance of all liquid biopsy methods. The pooled sensitivities, specificities, diagnostic odds ratios, and area under curve (AUC) of summary receiver operating characteristic curve for all liquid biopsy methods, exosomes, circulating tumor cells (CTCs), and cfDNA were calculated, respectively. A total of 62 articles involving 18 739 individuals were included. Fifty‐one articles were about cfDNA, five articles were about CTCs, and six articles were about exosomes. The overall performance of all liquid biopsy methods had a pooled sensitivity, specificity, and AUC of 0.77 (95% confidence interval [CI] 0.76‐0.78), 0.89 (95% CI 0.88‐0.90), and 0.9004, respectively. The sensitivities were 0.82 (95% CI 0.79‐0.85), 0.76 (95% CI 0.72‐0.80), and 0.76 (95% CI 0.75‐0.77) for CTCs, exosomes, and cfDNA, respectively. The specificities were 0.97 (95% CI95% CI 0.95‐0.99), 0.92 (95% CI 0.89‐0.94), and 0.88 (95% CI 0.87‐0.89) for CTCs, exosomes, and cfDNA, respectively. The AUC were 0.9772, 0.9037, and 0.8963 for CTCs, exosomes, and cfDNA, respectively. The overall performance of all liquid biopsy methods had great diagnostic value in detecting CRC, regardless of subtypes. Among all liquid biopsy methods, CTCs showed the best diagnostic performance.

Assessing the Impact of Circulating Tumor DNA (ctDNA) in Patients With Colorectal Cancer: Separating Fact From Fiction

Significant advances and increased awareness have been in made in the field of non-invasive liquid biopsies for cancer, spanning several malignancies from gastrointestinal, pulmonary, and other etiologies. Broadly, the genetic source material for liquid biopsies includes circulating tumor cells, cell-free circulating tumor DNA (ctDNA), or cell-free circulating tumor microRNA (mRNA). In this review, we specifically focus on ctDNA and its current role in colorectal cancer. While there are several commercially available assays that detect ctDNA, the utility of these products is still variable and therefore the clinical applications of ctDNA in the management of patients with cancer has yet to be determined. This is reflected by the recent joint review set forth by the American Society of Clinical Oncology (ASCO) and the College of American Pathologists (CAP), clarifying and somewhat tempering the present role of ctDNA in patients with cancer. This review provides additional detail regarding ctDNA in the limited setting of colorectal cancer. The increasing importance and promise of ctDNA remains an area of active research, and further prospective studies may enhance the clinical utility of ctDNA in the future.

Circulating cell free DNA as the diagnostic marker for colorectal cancer: a systematic review and meta-analysis

Background

Quantitative analyses of circulating cell-free DNA (cfDNA) are suggested to be a promising method for the detection of colorectal cancer, validated clinical relevance of cfDNA has not been published so far. Though some of the inconsistent results were published. This study is the first meta-analysis to systematically evaluate the diagnostic accuracy of circulating cfDNA as non-invasive biomarkers for colorectal cancer.

Results

Fourteen studies concerning a quantitative analysis of circulating cfDNA for the diagnosis of colorectal cancer met the inclusion criteria. Data includes 1,258 patients with colorectal cancer and 803 healthy individuals as control was analyzed. The summary estimates were as follow: sensitivity, 0.735 (95% CI 0.713–0.757); specificity, 0.918 (95% CI, 0.900–0.934); positive likelihood ratio, 8.295 (95% CI, 5.037–13.659); negative likelihood ratio, 0.300 (95% CI, 0.231–0.391); diagnostic odds ratio, 30.783 (95% CI, 16.965–55.856); and area under the curve, 0.8818 (95% CI, 0.88–0.93), respectively. Publication bias was not evident with Deeks’ funnel plot asymmetry test (p = 0.197).

Materials and Methods

A systematic literature was searched in PubMed, EMBASE, Cochrane Library and Chinese National Knowledge Infrastructure from their inception to August 07, 2017. Analyses were conducted by Meta-DiSc 1.4 and Stata 12.0. Diagnostic accuracy in sensitivity, specificity and aspects were pooled. Subgroup analyses and meta-regression were performed to identify the sources of heterogeneity. Clinical utility of the cfDNA was evaluated by Fagan nomogram.

Conclusions

Our meta-analysis suggested that the diagnostic accuracy of circulating cfDNA has unsatisfactory sensitivity but acceptable specificity for diagnosis of colorectal cancer. Furthermore, the integrity index (ALU247/ALU115) is better than absolute DNA concentration in diagnostic accuracy of colorectal cancer.

Serum DNA integrity index as a potential molecular biomarker in endometrial cancer

Background

Circulating cell-free DNA (cfDNA) and its integrity index may represent a rapid and noninvasive “liquid biopsy” biomarker, which gives important complementary information for diagnosis, prognosis, and treatment stratification in cancer patients. The aim of our study was to evaluate the possible role of cfDNA and its integrity index as a complementary tool for endometrial cancer (EC) management.

Methods

Alu-quantitative real-time PCR (qPCR) analysis wasprformed on 60 serum samples from preoperative EC patients randomly recruited. Both cfDNA content and DNA integrity index were measured by qPCR-Alu115 (representing total cfDNA) and qPCR-Alu247 (corresponding to high molecular weight DNA) and correlated with clinicopathologic characteristics. Lymphovascular space invasion (LVSI) was detected by hematoxylin and eosin staining. In case of doubt, LVSI status was further evaluate by immunohistochemistry using anti-CD31 and anti-CD34 antibodies.

Results

Total cfDNA content significantly increases in high grade EC. A significant decrease of DNA integrity index was detected in the subset of hypertensive and obese high grade EC. Serum DNA integrity was higher in samples with LVSI. The ordinal regression analysis predicted a significant correlation between decreased integrity index values and hypertension specifically in tumors presenting LVSI.

Conclusions

Our study supports the utility of serum DNA integrity index as a noninvasive molecular biomarker in EC. We show that a correlation analysis between cfDNA quantitative and qualitative content and clinicopathologic features, such as blood pressure level, body mass index (BMI) and LVSI status, could represent a potential predictive signature to help stratification approaches in EC.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-018-0688-4) contains supplementary material, which is available to authorized users.

Expressions of miRNAs in papillary thyroid carcinoma and their associations with the clinical characteristics of PTC

BACKGROUND

The sensitivity and specificity of biomarkers which have been used in clinical practice for diagnosis of papillary thyroid carcinoma (PTC) are low, it is essential to develop novel diagnostic and prognostic biomarkers for PTC.

OBJECTIVE

To explore the expressions of miR-940, miR-15a, miR-16 and IL-23 in PTC tissues and plasma and their associations with the clinical characteristics of PTC.

METHODS

We investigated the expressions of miR-940, miR-15a, miR-16 and IL-23 in plasma and thyroid tissues of PTC, nodular goiter and healthy people with qRT-PCR, and further analyzed the associations between their levels and the clinical characteristics of PTC.

RESULTS

Level of IL-23 expression was higher while levels of miR-940, miR-15a and miR-16 expression in the PTC tissues were lower compared with the nodular goiter tissues and perineoplastic thyroid tissues. And the levels of miR-940, miR-15a, miR-16 and IL-23 expression in the PTC tissues were associated with some clinical characteristics of PTC, including bilateral tumor, multicentricity, extrallyroidal invasion, cervical lymph node metastasis, distant metastasis and clinical advanced stages (III/IV).

CONCLUSIONS

Expressions of miR-940, miR-15a, miR-16 and IL-23 in PTC tissues might be useful biomarkers and promising targets in the diagnosis of papillary thyroid carcinoma.

Difluoromethylornithine in cancer: new advances

Difluoromethylornithine (DFMO; eflornithine) is an irreversible suicide inhibitor of the enzyme ornithine decarboxylase which is involved in polyamine synthesis. Polyamines are important for cell survival, thus DFMO was studied as an anticancer agent and as a chemoprevention agent. DFMO exhibited mainly cytostatic activity and had single agent efficacy as well as activity in combination with other chemotherapeutic drugs for some cancers and leukemias. Herewith, we summarize the current knowledge of the anticancer and chemopreventive properties of DFMO and assess the status of clinical trials.

The Prognostic Value of Circulating Cell-Free DNA in Colorectal Cancer: A Meta-Analysis

BACKGROUND

Circulating cell-free DNA (cfDNA) is a promising candidate biomarker for detection, monitoring and survival prediction of colorectal cancer (CRC). However, its prognostic significance for patients with CRC remains controversial. To derive a precise estimation of the prognostic significance of cfDNA, a meta-analysis was performed.

METHODS

We made a systematic search in data base of the Science Citation Index Embase and Pubmed for studies reporting prognostic data of cfDNA in CRC patients. The data of cfDNA on recurrences-free survival (RFS) and overall survival (OS) were extracted and measured in hazard rates (HRs) and 95% confident intervals (CIs). Subgroup analyses were carried out as well. Finally, the meta-analysis is accompanied with nine studies including 19 subunits.

RESULTS

The pooled HRs with 95% CIs revealed strong associations between cfDNA and RFS (HR [95%CI]=2.78[2.08-3.72], I(2)=32.23%, n=7) along with OS (HR [95%CI]=3.03[2.51-3.66], I(2)=29.24%, n=12) in patients with CRC. Entire subgroup analyses indicated strong prognostic value of cfDNA irrespective tumor stage, study size, tumor markers, detection methods and marker origin.

CONCLUSIONS

All the results exhibits that appearance of cfDNA in blood is an indicator for adverse RFS and OS in CRC patients.