An ultrasensitive method for noninvasive pan-cancer early detection based on targeted methylation sequencing of cell-free DNA.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 10544-10544
Author(s):  
Tiancheng Han ◽  
Yuanyuan Hong ◽  
Pei Zhihua ◽  
Song Xiaofeng ◽  
Jianing Yu ◽  
...  
Keyword(s):  
Cancer Patients ◽  
Cancer Detection ◽  
Real World ◽  
Early Stage ◽  
Validation Dataset ◽  
Cpg Sites ◽  
Free Dna ◽  
Cancer Types ◽  
Discovery Dataset ◽  
Pan Cancer

10544 Background: Screening the biomarkers from the cell-free DNA (cfDNA) of peripheral blood is a non-invasive and promising method for cancer diagnosis. Among diverse types of biomarkers, epigenetic biomarkers have been reported to be one of the most promising ones. Epigenetic modifications are widespread on the human genome and generally have strong signals due to the similar methylation patterns shared by adjacent CpG sites. Although some epigenetic diagnostic methods have been developed based on cfDNAs, few of them could be applied to pan-cancer and their sensitivities are barely satisfactory for early cancer detection. Methods: Targeted methylation sequencing was performed using our in-house-designed panel targeting regions with abundant cancer-specific methylation CpGs. The cfDNA samples from 80 healthy individuals and 549 cancer patients of 14 cancer types were separately sequenced. The dataset was randomly split into one discovery dataset and one validation dataset. Moreover, cfDNA samples from four cancer patients were diluted with the healthy cfDNAs to generate 12 in vitro simulated samples with low circulating tumor DNA (ctDNA) fraction. Additionally, DNAs extracted from 130 unmatched tumor formalin fixation and paraffin embedding (FFPE) samples of 10 cancer types were sequenced to screen the diagnostic biomarkers. Adjacent CpG sites were first merged into methylation-correlated blocks (MCB) according to their correlations of methylation levels in tumor DNAs. The MCBs with higher methylation levels in tumor DNAs than that of healthy cfDNAs (from the discovery dataset) were defined as our hypermethylation biomarkers. For each cfDNA sample, a hypermethylation score (HM-score) was computed to measure the overall methylation level difference of selected biomarkers. The performance of our method was evaluated with the real-world dataset, while the limit of detection was estimated using the simulated low-ctDNA samples. Results: Our model based on 37 hypermethylation MCB biomarkers achieved an area under the curve (AUC) of 0.89 and 0.86 in the real-world pan-cancer discovery and validation cfDNA datasets, respectively. Furthermore, the overall specificity and sensitivity are 100% and 76.19% in the discovery dataset, and 96.67% and 72.86% in the validation dataset. In the validation dataset, 28/40 (70%) of early-stage colorectal cancer patients and 10/20 (50%) of non-small-cell lung cancer patients were successfully diagnosed. Additionally, all the simulated samples with theoretical ctDNA factions over 0.5% were predicted as diseased, demonstrating the ability of our method to detect tumor signals at early stages. Conclusions: Our cfDNA-based epigenetic method outperforms currently available methods in various cancer types, and is promising to be applied to early-stage cancer detection and samples with low ctDNA fractions.

The prevalence of HLA LOH in Chinese pan-cancer patients and its correlation with genomic alterations.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e14521-e14521
Author(s):  
Jian Zhao ◽  
Xiaoxiong Xiao ◽  
Yue Li ◽  
Xuan Gao ◽  
Xiuqin Zhang ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
Cancer Patients ◽  
Early Stage ◽  
Large Population ◽  
Notch Pathway ◽  
Gene Panel ◽  
Oncogenic Signaling ◽  
Essential Components ◽  
Cancer Types ◽  
Pan Cancer

e14521 Background: Human leukocyte antigen (HLA) molecules are essential components involved in tumor antigen presentation. Loss of heterozygosity in HLA (HLA LOH) may facilitate tumor immune evasion. However, the large population study of HLALOH in Chinese pan-cancer patients remains to be explored. Methods: In this study, analysis were performed in 1504 advanced patients across 12 cancer types and 134 early-stage NSCLC patientsusing a 1021-gene panel. HLA LOH were analysis using LOHHLA algorithm. The consistency between target sequencing by 1021-gene panel and whole-exome sequencing (WES) was evaluated in 45 samples. Results: In 45 samples processed with both approaches, 95.6% (43/45) obtained concordant results. Among the 1638 patients, 24 were excluded due to homozygosity at all three HLA-Iloci. The prevalence of HLALOH in advanced patients presented considerable differences among cancer typeswith an average incidence of 45.6% (676/1482), ranging from 12.2% (prostate adenocarcinoma) to 68.0% (cervical squamous cell carcinoma). In NSCLC patients, there was an enrichment of HLALOH in both early-stage (I-IIIa) LUSC (24/88 [27.3%] of LUAD vs. 26/42 [61.9%] of LUSC, p<0.001) and advanced (IIIb-IV) LUSC. In 43.3% (293/676) patients harboring HLALOH, LOH co-occurred in HLA-A, B, and C. Consistent with previous studies, the occurrence of HLALOH was relevant to an elevated TMB level(median TMB 6.72 vs. 5.76, p<0.0001). In addition, the TMB level of patients with LOH at all three HLA-I loci was higher than those with LOH at only one HLA-I locus (median TMB 7.68 vs. 6.72, p=0.027).However, despite that MSI-H patients presented the highest incidence of TMB-H (TMB≥10.56), the incidence of HLALOH decreased in these patients. Alterations of multiple signaling pathways are enriched in HLALOH patients, including CPF (checkpoint factor) pathway, FA (Fanconi anemia) pathway, p53 pathway, RTK/RAS pathway, Notch pathway, Hippo pathway and Nrf2 pathway(p<0.0001, p=0.023, p<0.0001, p<0.0001, p=0.032, p=0.013, p=0.003, respectively, Table).Several oncogenes, such as TP53 and LRP1B, had higher alteration frequencies in the HLALOH group(p<0.001 for TP53,p<0.05 for LRP1B, Table 1). Conclusions: The 1021-gene panel could be applied for HLALOH analysis, provided that the relevant regions are well captured. The prevalence of HLALOH in Chinese cancer patients presents considerable differences across cancer types. Besides, the occurrence of HLA LOH was accompanied by higher alteration frequencies in several oncogenes and oncogenic signaling pathways. These insights may provide valuable information for clinical practice and follow-up research.[Table: see text]

Changes in DNA hydroxymethylation for the detection of multiple cancers in plasma cell-free DNA.

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. 3058-3058
Author(s):  
Anna Bergamaschi ◽  
Francois Collins ◽  
Chris Ellison ◽  
Yuhong Ning ◽  
Gulfem Guler ◽  
...  
Keyword(s):  
Cancer Patients ◽  
Tumor Tissue ◽  
Early Stage ◽  
Genomic Feature ◽  
Cell Free Dna ◽  
Early Stage Disease ◽  
Free Dna ◽  
Genome Wide ◽  
Cancer Types

3058 Background: Methylation and hydroxymethylation of cytosines enable the epigenomic regulation of gene suppression and activation. 5-hydroxymethyl-cytosine (5hmC) is globally decreased in tumor tissue. However, genome-wide analysis using precise 5hmC labelling techniques reveals more nuanced changes upon tumorigenesis and raises the possibility that this loss could be exploited for developing a cancer biomarker. This suggests that 5hmC profiles might enable discrete classification of not only tumor tissue but also of tumor cell-free DNA (cfDNA). We sought to identify genome-wide 5hmC changes in plasma based cfDNA from cancer patients representing multiple disease types, stages and clinical characteristics in comparison with non-cancer patients. Methods: cfDNA was isolated from plasma, enriched for the 5hmC fraction using chemical labelling, sequenced, and aligned to the genome to determine 5hmC counts per genomic feature. Regularized regression models were constructed to classify cancer samples (age matched or corrected for smoking status) on non-overlapping training (80% of all samples) and test sample sets (20% of all samples). Results: 226 non-cancer patients and 278 cancers across four cancer types (breast, colorectal, lung-squamous and pancreas) were included in this study, where more than 60% of cancer samples were early stage disease (I or II). Upon comparison with non-cancer samples, 5hmC peaks have reduced enrichment in exons in breast, colorectal and lung cancer but not in pancreatic cancer. Further, 5hmC peaks in pancreas show different patterns of enrichment in 3’UTR, translational termination sites, promoters and LTR. Overall 5hmC signal density was reduced in late stage cancers across all four diseases. The ability to classify non-cancer versus cancer patients was evaluated via cross-validation of out of fold prediction in the training set with AUC > 0.84 for all four cancer types. Further, test set sensitivity across all four cancer types was found to be > 66% with 98% specificity. Conclusions: These findings suggest that 5hmC changes in plasma cfDNA enable classification of early stages of breast, colorectal, lung-squamous and pancreas cancer and are promising biomarkers for disease detection.

A dual target sequencing solution to assess genomic and epigenomic alterations in cell-free DNA with no sample splitting.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 3043-3043
Author(s):  
Grace Q. Zhao ◽  
Yun Bao ◽  
Heng Wang ◽  
Wanping Hu ◽  
John Coller ◽  
...  
Keyword(s):  
Cancer Detection ◽  
Dna Analysis ◽  
Residual Disease ◽  
Early Stage ◽  
Cancer Cell Line ◽  
Assay Sensitivity ◽  
Cell Free Dna ◽  
Target Sequencing ◽  
Free Dna ◽  
Dual Analysis

3043 Background: Assessing the genomic and epigenomic changes on plasma cell-free DNA (cfDNA) using next-generation sequencing (NGS) has become increasingly important for cancer detection and treatment selection guidance. However, two major hurdles of existing targeted NGS methods make them impractical for the clinical setting. First, there is no comprehensive, end to end, kit solution available for targeted methylation sequencing (TMS), let alone one that analyzes both mutation and methylation information in one assay. Second, the low yield of cfDNA from clinical blood samples presents a major challenge for conducting multi-omic analysis. Thus, an assay that is capable of both genomic and epigenomic analysis would be advantageous for clinical research and future diagnostic assays. Methods: Here, we report the performance of Point-n-SeqTM dual analysis, a kit solution that can provide in-depth DNA analysis with highly flexible and customizable focused panels to enable both genomic and epigenomic analysis without sample splitting. With custom panels of tens to thousands of markers designed with > 99% first-pass success rate, we conducted both performance validation and multi-center, multi-operator, reproducibility studies. Using spike-in titration of cancer cell-line gDNA with known mutation and methylation profiles, Point-n-Seq assay achieved a reliable detection level down to 0.003% of tumor DNA with a linear relationship between the measured and expected fractions. Benchmarked with conventional targeted sequencing and methylation sequencing, Point-n-Seq solution also demonstrated improved performance, speed and shortened hands-on time. Results: In a pilot clinical study, a colorectal cancer (CRC) TMS panel covering 560 methylation markers and a mutation panel with > 350 hotspot mutations in 22 genes were used in the dual assay. Using 1ml of plasma from late-stage CRC patients, cancer-specific methylation signals were detected in all samples tested, and oncogenic mutations. In an early-stage cohort (33 stage I/II CRC patient ), comparison of the analysis between tumor-informed, personalized-mutation panels (̃100 private SNVs) for each patient and the tumor-independent CRC methylation panels were conducted. The initial results showed that tumor-independent TMS assay achieved a comparable detection compared to the personalized tumor-informed approach. Moreover, cfDNA size information (fragmentome) is also integrated into the analysis of the same Point-n-Seq workflow to improve the assay sensitivity. Conclusions: Point-n-Seq dual analysis is poised to advance both research and clinical applications of early cancer detection, minimal residual disease (MRD), and monitoring.

Exploration of the MSI landscape in Chinese pan-cancer patient by Next-Generation Sequencing.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e14576-e14576
Author(s):  
Xinlu Liu ◽  
Jiasheng Xu ◽  
Jian Sun ◽  
Deng Wei ◽  
Xinsheng Zhang ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Correlation Analysis ◽  
Cancer Patients ◽  
Cancer Type ◽  
Multiple Tumor ◽  
Treatment Plans ◽  
Cancer Types ◽  
Chinese Cancer Patients ◽  
Colorectal Cancer Patients ◽  
Pan Cancer

e14576 Background: Clinically, MSI had been used as an important molecular marker for the prognosis of colorectal cancer and other solid tumors and the formulation of adjuvant treatment plans, and it had been used to assist in the screening of Lynch syndrome. However, there were currently few reports on the incidence of MSI-H in Chinese pan-cancer patients. This study described the occurrence of MSI in a large multi-center pan-cancer cohort in China, and explored the correlation between MSI and patients' TMB, age, PD-L1 expression and other indicators. Methods: The study included 8361 patients with 8 cancer types from multiple tumor centers. Use immunohistochemistry to detect the expression of MMR protein (MLH1, MSH2, MSH6 and PMS2) in patients with various cancer types to determine the MSI status and detect the expression of PD-L1 in patients. Through NGS technology, 831 genes of 8361 Chinese cancer patients were sequenced and the tumor mutation load of the patients was calculated. The MSI mutations of patients in 8 cancer types were analyzed and the correlation between MSI mutations of patients and the patient's age, TMB and PD-L1 expression was analyzed. Results: The test results showed that MSI patients accounted for 1.66% of pan-cancers. Among them, MSI-H patients accounted for the highest proportion in intestinal cancer, reaching 7.2%. The correlation analysis between MSI and TMB was performed on patients of various cancer types. The results showed that: in each cancer type, MSI-H patients had TMB greater than 10, and 26.83% of MSI-H patients had TMB greater than 100 in colorectal cancer patients. The result of correlation analysis showed that there was no significant correlation between the patient's age and the risk of MSI mutation ( P> 0.05). In addition to PAAD and LUAD, the expression of PD-L1 in MSI-H patients was higher than that in MSS patients in other cancer types( P< 0.05). The correlation analysis between PD-L1 expression and TMB in patients found that in colorectal cancer, the higher the expression of PD-L1, the higher the patient's TMB ( P< 0.05). Conclusions: In this study, we explored the incidence of MSI-H in pan-cancer patients in China and found that the TMB was greater than 10 in patients with MSI-H. Compared with MSS patients, MSI-H patients have higher PD-L1 expression, and the higher the PD-L1 expression in colorectal cancer, the higher the TMB value of patients.

A pan-cancer study on characteristic of CDK4/6 amplification between Chinese and Western patients.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e15074-e15074
Author(s):  
Yamin Zhang ◽  
Zilin Cui ◽  
Rui Shi ◽  
Xiaolong Liu ◽  
Yang Li ◽  
...  
Keyword(s):  
Soft Tissue ◽  
Liver Cancer ◽  
Soft Tissue Sarcoma ◽  
Lung Adenocarcinoma ◽  
Ovarian Carcinoma ◽  
Cancer Patients ◽  
Stomach Carcinoma ◽  
Chinese Cohort ◽  
Cancer Types ◽  
Pan Cancer

e15074 Background: CDK4/6 kinases associate with cyclin D proteins during transition from G1 to S phase of the cell cycle. Amplification of CDK4/6 may elicit the activity of cyclin D, which hyperphosphorylates RB, ultimately leading to uncontrolled cell proliferation. Currently, three CDK4/6 inhibitors are used in breast cancer, ovarian cancer and sarcoma. Herein, we investigate the prevalence of CDK4/6 amplification in Chinese and Western cancer patients, hope to find more cancer subtypes with CDK4/6 amplification. Methods: Next-generation sequencing data and clinical data were collected from 10828 TCGA pan-cancer patients (Western cohort). A 539-gene panel targeted sequencing assay was performed on FFPE tumor samples from 4181 Chinese pan-cancer patients (Chinese cohort). CDK4 and CDK6 amplification were calculated on the two cohorts following the same criteria. Results: In total, 182 (4.4%) of the 4181 Chinese patients and 529 (4.9%) of the 10828 Western patients had CDK4 amplification, 133 (3.2%) of the 4181 Chinese patients and 475 (4.4%) of the 10828 Western patients had CDK6 amplification. In Western cohort, the top 5 CDK4 amplification-associated cancer types were sarcoma, glioblastoma multiforme, lung adenocarcinoma, ovarian carcinoma, and adrenocortical carcinoma, and the top 5 CDK6 amplification-associated cancer types were esophageal carcinoma, ovarian carcinoma, lung squamous cell carcinoma, stomach adenocarcinoma, sarcoma. In Chinese cohort, the top 5 CDK4 amplification-associated cancer types were lung adenocarcinoma, melanoma, sarcoma, stomach carcinoma, liver cancer, and the top 5 CDK6 amplification-associated cancer types were lung adenocarcinoma, stomach carcinoma, liver cancer, melanoma, glioma. In addition, CDK4 amplification in Chinese cohort, 22 (11%) of the 203 Chinese bone and soft tissue sarcoma patients had CDK4 amplification, and 4 (2%) of the 203 had CDK6 amplification. Bone and soft tissue sarcoma types with CDK4 / 6 amplification including soft tissue sarcoma, bone cancer, fibrosarcoma, chondrosarcoma, rhabdomyosarcoma, liposarcoma, synovial sarcoma. Conclusions: Our study provided a characteristic of CDK4/6 amplification in Chinese and Western pan-cancer patients. Analysis revealed frequent CDK4 / 6 amplification in lung cancer, sarcoma, stomach carcinoma, ovarian carcinoma and liver cancer. It is suggested patient with these cancer types may potentially benefit from CDK4/6 inhibitor.

Unveiling the real-world outcomes of breast cancer (BC) patients with taxanes-induced neuropathy using a digital patient-powered network (PPN).

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. e18248-e18248
Author(s):  
Raanan Berger ◽  
Lior Hasid ◽  
Irad Deutsch ◽  
Eliran Malki ◽  
Maytal Bivas-Benita
Keyword(s):  
Cancer Patients ◽  
Real World ◽  
Healthcare Costs ◽  
Patient Reported Outcomes ◽  
Early Stage ◽  
Treatment Decisions ◽  
Real World Evidence ◽  
Patient Reported ◽  
The Us ◽  
Disease Stages

e18248 Background: Taxanes-induced neuropathy is common in BC patients receiving taxanes, forcing dose reductions and treatment delays and posing serious challenges for the long-term patient QoL. Discovering neuropathy predictors in patients could guide better treatment decisions, improved QoL and reduce healthcare costs. Belong digital PPN is a social network for cancer patients and caregivers that supports disease management. In this study we used our artificial intelligence (AI) engine to classify the prevalence, characteristics and taxanes-induced neuropathy status of BC patients. Methods: We analyzed real-world patient-reported outcomes provided voluntarily and anonymously from users on the Belong PPN. Data from BC patients reporting treatment with taxanes was extracted and additional analysis segmented the data to those who experienced neuropathy and those who did not. Further validation of the data was performed by our research team to assure accuracy. Results: We evaluated 169 BC cancer patients from the US treated with taxanes. In the cohort 72% were Paclitaxel-treated and 28% Docetaxel-treated at various disease stages: 68% at early stage BC (0-2) and 32% at the advanced/metastatic stages (3-4). 83% of Paclitaxel-treated patients and 67% of Docetaxel-treated patients reported experiencing neuropathy in the Belong platform. These real-world reports indicated significantly higher incidence of taxane-induced neuropathy in comparison to literature summarizing data from clinical trials, suggesting neuropathy incidence of 27% for paclitaxel and 16% for docetaxel (grades 2-4). Conclusions: Real-world patient-reported outcomes from the Belong PPN captured the prevalence of taxanes-induced neuropathy in BC patients and correlated it to the specific drug in use. Evidence for higher incidence of taxanes-induced neuropathy may lead to lower patient QoL and higher healthcare costs and should stimulate better treatment decisions. Further exploration of the gap between controlled clinical studies and real-world evidence is urgently needed to understand the true patient outcomes and optimize healthcare accordingly.

The prevalence of CDK12 alterations in Chinese cancer patients and the association with tumor mutation burden(TMB) and survival.

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e13663-e13663
Author(s):  
Ke Li ◽  
Xi Guo ◽  
Yunhua Mao ◽  
Mengmei Yang ◽  
Mengli Huang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Patients ◽  
Molecular Subtype ◽  
Prostate Adenocarcinoma ◽  
Chinese Patients ◽  
Cyclin Dependent Kinase ◽  
Poor Prognostic Factor ◽  
Cancer Types ◽  
Chinese Cancer Patients ◽  
Pan Cancer

e13663 Background: Cyclin-dependent kinase 12 (CDK12) is a cyclin-dependent kinase that regulates transcription and RNA splicing, thereby modulating multiple cellular processes. It has been suggested that CDK12 loss-of-function mutations lead to a higher neoantigen burden and favorable responses to PD-1 inhibitors in advanced prostate cancer. Given this potentially actionable molecular subtype, we sought to determine the prevalence of CDK12 alterations in Chinese cancer patients and the association with TMB and overall survival(OS). Methods: The prevalence of CDK12 alterations were queried in 3D Medicines database with 15,745 Chinese cancer patients involved. Whole-exome sequencing data of 464 patients with prostate adenocarcinoma(PRAD) from the Cancer Genome Altas (TCGA) were downloaded to explore the association between CDK12 gene alteration and OS. And the association with TMB were analyzed in a cohort of 731 patients with various cancer types published by Memorial Sloan Kettering (MSKCC) (Samstein et al., Nature Genetics, 2019). Results: Any CDK12 and known or likely deleterious CDK12 mutations were identified in 598(3.8%) and 98(0.62%) patients, respectively. Across all cancer types, prostate adenocarcinoma(PRAD) was found to have the highest frequency of deleterious mutations(8.75%, 23/263), followed by breast cancer (4.97%, 25/503). Mutations were also detected in multiple cancer types including bladder cancer, ovarian cancer, lung cancer, colorectal cancer and so on with a frequency of less than 1%. CDK12 mutations were associated with shorter OS (HR = 15.25; 95% CI, 2.88-80.73; p < 0.001) in TCGA PRAD and cholangiocarcinoma datasets, which was not seen in other cancer types. Patients harboring CDK12 mutation had a significant higher TMB(p < 0.001) in the pan-cancer study of publicly-available cohort from MSKCC. Conclusions: CDK12 alterations existed across tumor types in Chinese patients with relatively high frequencies detected in PRAD and breast cancer and represent extremely rare events in multiple cancers. CDK12 mutation was a poor prognostic factor in PRAD and cholangiocarcinoma. In a pan cancer analysis patients with CDK12 mutation tended to have a significant higher TMB and may benefit from PD-1/L1 blockade immunotherapy.

scholarly journals Applied mathematics and nonlinear sciences in the war on cancer

2016 ◽  
Vol 1 (2) ◽  
pp. 423-436 ◽  
Author(s):  
Víctor M. Pérez-García ◽  
Susan Fitzpatrick ◽  
Luis A. Pérez-Romasanta ◽  
Milica Pesic ◽  
Philippe Schucht ◽  
...  
Keyword(s):  
Mathematical Models ◽  
Cancer Patients ◽  
Real World ◽  
Mathematical Knowledge ◽  
Applied Mathematics ◽  
Specific Cancer ◽  
Real World Applications ◽  
Cancer Types ◽  
Optimized Treatment

AbstractApplied mathematics and nonlinear sciences have an enormous potential for application in cancer. Mathematical models can be used to raise novel hypotheses to test, develop optimized treatment schedules and personalize therapies. However. this potential is yet to be proven in real-world applications to specific cancer types. In this paper we discuss how we think mathematical knowledge may be better used to improve cancer patients’ outcome.

scholarly journals Circulating DNA, a Potentially Sensitive and Specific Diagnostic Tool for Future Medicine

Dose-Response ◽  
2019 ◽  
Vol 17 (4) ◽  
pp. 155932581989101
Author(s):  
Fan Jiang ◽  
Xiaoxiao Yang ◽  
Xiping He ◽  
Mingming Yang
Keyword(s):  
Early Stage ◽  
Point Of Care ◽  
Circulating Dna ◽  
Fetal Cell ◽  
Early Screening ◽  
Cell Free Dna ◽  
Promising Tool ◽  
Free Dna ◽  
Cancer Types ◽  
Commercial Kits

Liquid biopsy has the great potential of detecting early diseases before deterioration and is valued for screening abnormalities at early stage. In oncology, circulating DNA derived from shed cancer cells reflects the tissue of origin, so it could be used to locate tissue sites during early screening. However, the heterogenous parameters of different types limit the clinical application, making it inaccessible to encompass all the cancer types. Instead, for reproducible scenario as pregnancy, fetal cell-free DNA has been well utilized for screening aneuploidies. Noninvasive and convenient as is, it would be of great value in the next decades far more than early diagnosis. This review recapitulates the discovery and development of tumor and fetal cell-free DNA. The common factors are also present that could be taken into consideration when collecting, transporting, and preserving samples. Meanwhile, several protocols used for purifying cell-free DNA, either classic ones or through commercial kits, are compared carefully. In addition, the development of technologies for analyzing cell-free DNA have been summarized and discussed in detail, especially some up-to-date approaches. At the end, the potential prospect of circulating DNA is bravely depicted. In summary, although there would be a lot of efforts before it’s prevalent, cell-free DNA remains a promising tool in point-of-care diagnostic medicine.

Sign in / Sign up

Export Citation Format

Share Document