Application of circulating free DNA in the diagnosis and treatment of hepatocellular carcinoma / 临床肝胆病杂志

Hepatocellular carcinoma has a low early diagnostic rate, and there is a lack of highly sensitive and specific tumor markers. In recent years, fluid biopsy technique, represented by circulating free DNA (cfDNA), has become an auxiliary method for the diagnosis of cancer and has attracted more and more attention due to its advantages of noninvasiveness, convenience, and repeatability. With reference to the recent studies in China and foreign countries, this article summarizes and analyzes the advances in cfDNA in the diagnosis and treatment of hepatocellular carcinoma from the aspects of biological characteristics, detection techniques, and clinical application, so as to provide a basis for clinical diagnosis and treatment.

Progress in the application of tumor DNA in the diagnosis and treatment of esophageal cancer / 国际外科学杂志

With the development of precision medicine in the field of tumor,thanks to the latest screening technology,the demand for real-time monitoring of tumor is increasingly high.Traditional tissue biopsy is not suitable for repeated due to clinical problems such as puncture clinical risk and tumor heterogeneity.Ultrasound,endoscopy and other imaging examinations are highly subjective,and it is difficult to detect small lesions,and increasingly unable to meet the requirements of real-time monitoring.However,circulating tumor DNA,with its advantages of simple sample acquisition,small trauma,repeatability and real-time monitoring efficacy,has an important application prospect in tumor diagnosis and treatment.Based on the latest reports at home and abroad,this paper reviews the research progress of circulating tumor DNA in the early diagnosis,treatment and prognosis of esophageal cancer.

Combined detection of KRAS, NRAS, BRAF and PIK3CA mutations in the plasma and tumor tissues of colorectal cancer patients / 中华病理学杂志

Objective@#To analyze the concordance of KRAS, NRAS, BRAF and PIK3CA gene mutations detected in plasma and matched tumor tissues in colorectal cancer patients, in order to provide good evidences to support plasma could be a potential surrogate of tumor tissue for gene mutation test.@*Methods@#One hundred and seventy-five cases of colorectal cancer were collected at the First Hospital of Jilin University, from October 2016 to October 2017.There were 101 males and 74 females, their ages ranged from 28 to 85 years,with median age of 59 years. The KRAS, NRAS, BRAF and PIK3CA gene mutations in the plasma and paired tumor specimens of all patients were detected by next generation sequencing.@*Results@#The results of tissue samples test were gold standard. Comparison of the four genes showed that concordance rates between plasma and tissue samples were 81.1%(Kappa=0.543), 99.4%(Kappa=0.886), 99.4% (Kappa=0.886) and 97.7%(Kappa=0.714) respectively for KRAS, NRAS, BRAF and PIK3CA. The plasma detection rates of these genes were related to tumor stage(P=0.001), but not to gender(P=0.468) and age(P=1.000) of patients.@*Conclusions@#The study shows a high concordance of KRAS, NRAS, BRAF and PIK3CA gene mutations in plasma against mutation status in tumor tissue. In colorectal cancer, tumor tissue remains the best specimen for gene detection. However, patients from tumor tissue specimens cannot be obtained, especially those with advanced metastases, plasma can be used instead of tissue to detect the mutation status of KRAS, NRAS, BRAF and PIK3CA to guide targeted therapy.

Estudio de mutaciones en los genes IDH1 e IDH2 en una muestra de gliomas de población colombiana / Study of mutations in IDH1 and IDH2 genes in a sample of gliomas from Colombian population

Resumen Introducción. Los gliomas son los tumores primarios más comunes del sistema nervioso central y se clasifican de I a IV según su grado de malignidad. En recientes investigaciones se ha encontrado que su aparición está relacionada con mutaciones en el exón 4 de los genes que codifican las deshidrogenasas de isocitrato 1 y 2 (IDH1: codón 132; IDH2: codón 172). Objetivo. Determinar la frecuencia de mutaciones en los genes IDH1 e IDH2 en una muestra de gliomas de pacientes colombianos. Materiales y métodos. La extracción de ADN se hizo a partir de tejido tumoral. El exón 4 de los genes IDH1 e IDH2 se amplificó mediante PCR utilizando iniciadores específicos y, posteriormente, se secuenciaron. Para la determinación de las mutaciones, se emplearon los programas 4Peaksy MAFFT. Resultados. Se determinó la presencia de mutaciones en el gen IDH1 en el 34 % de las muestras, con predominio de la mutación no sinónima R132H. En el 7,5 % de los casos se detectaron mutaciones en el gen IDH2, principalmente las mutaciones no sinónimas R172K y R172W. Conclusiones. La frecuencia de mutaciones en los genes IDH1 e IDH2 en la muestra fue similar a la reportada en otros estudios. El análisis de estas mutaciones puede ser importante como factor pronóstico y para su uso como potenciales blancos terapéuticos en gliomas.

Abstract Introduction: Gliomas are the most common primary tumors of the central nervous system and, according to their malignancy, they are graded from I to IV. Recent studies have found that there is an association between gliomas and mutations in exon 4 of genes that codify for isocitrate dehydrogenases 1 and 2 (IDH1: codon 132; IDH2: codon 172). Objective: To establish the frequency of mutations in IDH1 and IDH2 in a sample of gliomas from Colombian population. Materials and methods: DNA was extracted from tumor tissue. The exon 4 of IDH1 and IDH2 was amplified by PCR using specific primers and subsequently sequenced. Mutations were determined using the 4Peaks MAFFT programs. Results: We found mutations in the IDH1 gene in 34% of the glioma samples, with a predominance of the nonsynonymous mutation R132H. Mutations in the IDH2 gene were found in 7.5% of cases, with a predominance of the nonsynonymous R172K and R172W mutations. Conclusions: The frequency of mutations in the IDH1 and IDH2 genes in the sample was similar to that reported in other studies. The analysis of these mutations may be important to establish prognostic factors and for the development of future therapeutic targets in gliomas.

Current situation and prospect of breast cancer liquid biopsy / 中华外科杂志

Liquid biopsy is a diagnostic approach by analyzing body fluid samples. Peripheral blood is the most common sample. Urine, saliva, pleural effusion and ascites are also used. Now liquid biopsy is mainly used in the area of neoplasm diagnosis and treatment. Compared with traditional tissue biopsy, liquid biopsy is minimally invasive, convenient to sample and easy to repeat. Liquid biopsy mainly includes circulating tumor cells and circulating tumor DNA (ctDNA) detection. Detection of ctDNA requires sensitive and accurate methods. The progression of next-generation sequencing (NGS) and digital PCR promote the process of studies in ctDNA. In 2016, Nature published the result of whole-genome sequencing study of breast cancer. The study found 1 628 mutations of 93 protein-coding genes which may be driver mutations of breast cancer. The result of this study provided a new platform for breast cancer ctDNA studies. In recent years, there were many studies using ctDNA detection to monitor therapeutic effect and guide treatment. NGS is a promising technique in accessing genetic information and guiding targeted therapy. It must be emphasized that ctDNA detection using NGS is still at research stage. It is important to standardize ctDNA detection technique and perform prospective clinical researches. The time is not ripe for using ctDNA detection to guide large-scale breast cancer clinical practice at present.

Detection of circulating tumor DNA in epidermal growth factor receptor-TKI relapsed non-small cell lung cancer patients using next-generation sequencing and an analysis of the resistant mechanisms / 中华病理学杂志

Objective@#Next-generation sequencing (NGS) was performed on circulating tumor DNA (ctDNA) samples from tyrosine kinase inhibitor (TKI)-naïve non-small cell lung cancers (NSCLC) and TKI-relapsed NSCLC to investigate the clinical value.@*Methods@#A total of 381 plasma samples from patients who were diagnosed with lung cancer in Cancer Hospital Chinese Academy of Medical Sciences from March 2017 to May 2018 were enrolled in the study. NGS was performed using a custom-designed panel that covers 10 lung cancer-related driven genes. Paired plasma-tissue samples from 39 patients were collected to analyses the sensitivity and specificity of detecting driver gene mutations using ctDNA. NGS was also performed on plasma samples from TKI-relapsed patients to identify TKI resistance mechanisms.@*Results@#Thirty-nine plasma samples collected from 39 NSCLC patients (including 21 female and 18 male) with corresponding tissue biopsies were analyzed for the sensitivity and specificity. The average age was 56 years (range 29 to 82 years). A high concordance of 84.62% (33/39) was observed between ctDNA and tissue biopsies. Compared with tissue biopsies, NGS sensitivity for ctDNA was 82.14% and specificity was 90.91%.Among these 39 patients, 34 were advanced stage patients (III-IV stage). The concordance, sensitivity, and specificity for ctDNA among the advanced stage patients were 88.24% (30/34), 86.36% (29/34) and 91.67% (31/34), respectively. Among the 381 plasma samples [including 231 TKI-naïve patients and 150 epithelial growth factor receptor(EGFR)-TKI relapsed patients], EGFR mutation was the most common driver gene among the 221 TKI-naïve lung adenocarcinoma patients (32.58%, 72/221). For 133 patients who progressed after first-generation EGFR-TKI, T790M was found to be the most frequent resistant mechanism (39.10%, 52/133), as well as bypass activation (3.01%, 4/133; such as MET amplification and ERBB2 amplification). Among those first-generation EGFR-TKI relapsed patients with EGFR sensitive mutations, T790M was detected in 53.06% (52/98). For the 17 patients who progressed after third-generation EGFR-TKI, C797S was found to be the most common resistant mechanism (4/17).@*Conclusions@#The concordance, sensitivity and specificity between ctDNA and tissue biopsies are acceptable. ctDNA analysis provides valuable information for lung cancer patients′ targeted treatment, especially for patients not fitted for biopsies.

Progress of circulating tumor DNA detection in cancer / 中国基层医药

Peripheral blood circulating tumor DNA(ctDNA) is a kind of DNA that is released into the blood circulation system after the tumor cell somatic cell DNA is exfoliated or when the cell apoptosis is released.ctDNA is a characteristic tumor biomarker, known as " liquid biopsy" . It can reflect the invasion and metastasis of the tumor, and can monitor the effect and prognosis of the tumor.The current research is mainly focused on relatively mature breast cancer, lung cancer and other diseases.In this study, the development of ctDNA inspection technology and its current research status at home and abroad are reviewed.

Advances of liquid biopsy in the diagnosis and treatment of tumor / 国际肿瘤学杂志

Liquid biopsy mainly focuses on tumor diagnosis,metastasis monitoring,individualized treatment monitoring,curative effect evaluation and prognostic judgment.The main targets include circulating tumor cells,circulating tumor DNA and exosomes.At present,the liquid biopsy target has been used in the clinical monitoring of some tumors,and has good clinical results,but there are still many cha-llenges.

Clinical significance of colposcopy combined with DNA quantitative analysis for cervical cancer and precancerous lesions / 中国医师杂志

Objective To explore the clinical value of DNA quantitative analysis combined with colposcopy in the diagnosis of cervical cancer and precancerous lesions.Methods From January 2015 to January 2017, 500 women with sexual history were enrolled for obstetrics and gynecology.The sensitivity, specificity, and accuracy of DNA quantitative analysis, colposcopy, and the combination of them were evaluated by the pathological examination.Results The DNA quantitative analysis showed that the sensitivity of cervical lesions was 73.75％, the specificity was 94.05％,the positive predictive value was70.24％, and the accuracy rate was 90.8％.Colposcopy showed that the sensitivity of cervical lesions was 82.5％, specificity was 91.43％, positive predictive value was 64.71％, and the accuracy rate was 90.0％.When the two were used together, the sensitivity was 87.5％, the specificity was 95.71％, and the highest accuracy was 94.4％.When three methods were compared together, the differences among the specificity and the accuracy were statistically significant (P ＜ 0.05).For any pairwise comparison, the accuracy of the combined examination was better than that of DNA quantitative analysis and colposcopy (P ＜ 0.05).The specificity of combined examination was significantly better than that of colposcopy (P ＜ 0.05).The sensitivity of combined examination was better than that of DNA quantitative analysis (P ＜ 0.05).Conclusions DNA quantitative analysis combined with colposcopy screening has a higher sensitivity, specificity and accuracy, and it has the best diagnostic value for screening of cervical cancer and precancerous lesions.

Exploratory study of circulating tumor DNA detection in early breast cancer: an analysis of 75 next-generation sequencing results / 中华外科杂志

Objective@#To explore the utility of circulating tumor DNA detection in early breast cancer by using next-generation sequencing.@*Methods@#This exploratory study of circulating tumor DNA detection is for early invasive breast cancer patients treated in Breast Disease Center, Peking University First Hospital from December 2015 to July 2016. Plasma samples were collected and were used to isolate plasma cell-free DNA.Exons or hotspots of 247 cancer related genes were sequenced by next-generation sequencing. Mutations and their correlation with clinic-pathological factors were analyzed. The correlation between mutations and clinic-pathological factors was evaluated by χ2 test or Fisher′s exact test.@*Results@#Seventy-five patients were enrolled in this study. All patients were female and aged from 31 to 88 years with median age of 58 years. All patients′ clinic-pathological records were complete. Sixty-four mutations in 18 genes (ALK, BCR, ERBB2, ROS1, PDGFRA, EGFR, FGFR2, CYP1B1, CALR, CASP7, BRAF, FGFR1, FGFR3, MET, NRAS, PTEN, KIT, SOD2) were detected in 47 (62.7%) among all 75 patients.Exons were captured in 10 genes, and mutations in 2 of 3 genes analyzed were clustered. Gene mutations were not correlated with menopausal status, histological type, primary tumor (T), regional lymph nodes (N), TNM stage, histological grade, estrogen receptor status, progesterone receptor status, human epidermal growth factor receptor 2 status, Ki-67 and molecular subtype (all P>0.05).@*Conclusion@#Circulating tumor DNA sequencing by next-generation sequencing was useful for detecting breast cancer-related mutations.

The progression of tumor liquid biopsy and its applications in precision medicine / 中华外科杂志

Malignant tumor is the most heterogeneous human disease, and it has been gradually reached the consensus in clinical oncology that the personalized treatment of tumor patients should be directed by molecular diagnostics. However, the ever-changing characteristic of tumor in heterogeneity and the fact that tissue samples are usually unavailable highlight the function and significant of liquid biopsy. The material that could be used in liquid biopsy are mainly the circulating tumor DNA, circulating tumor cells and extracellular vesicles, which though have their own advantages and disadvantages, but could complement to each other, thus accurately and comprehensively reflecting the characteristic of the tumor and gave the best direction for patient′s individualized therapy. This article reviewed the recent advances of liquid biopsy and explained its importance in tumor precision medicine.

Application of liquid biopsy in the diagnosis and treatment of colorectal cancer / 中华检验医学杂志

Liquid biopsy plays an important role in the process of precision medical treatment.Its clinical value in the diagnosis and treatment of various diseases has being constantly proved.Colorectal cancer with high incidence begins subtly.The applicaiton of efficient early screening and diagnostic methods can effectively reduce the disease damage,and the implementation of precise post-operative and medication monitoring as the guidance for therapeutic strategy is helpful to improve the prognosis of patients.We should seize the opportunity to promote the transformation of research findings into the clinical application of colorectal cancer.Clinicians,technicians and regulators should face up and work together to overcome the challenges met during the process of clinical liquid biopsy.

Circulating Tumor Cell and Cell-free Circulating Tumor DNA in Lung Cancer / 전남의대학술지

Circulating tumor cells (CTCs) are tumor cells that are separated from the primary site or metastatic lesion and disseminate in blood circulation. CTCs are considered to be part of the long process of cancer metastasis. As a 'liquid biopsy', CTC molecular examination and investigation of single cancer cells create an important opportunity for providing an understanding of cancer biology and the process of metastasis. In the last decade, we have seen dramatic development in defining the role of CTCs in lung cancer in terms of diagnosis, genomic alteration determination, treatment response and, finally, prognosis prediction. The aims of this review are to understand the basic biology and to review methods of detection of CTCs that apply to the various types of solid tumor. Furthermore, we explored clinical applications, including treatment monitoring to anticipate therapy resistance as well as biomarker analysis, in the context of lung cancer. We also explored the potential use of cell-free circulating tumor DNA (ctDNA) in the genomic alteration analysis of lung cancer.

Circulating Tumor Cell and Cell-free Circulating Tumor DNA in Lung Cancer / 전남의대학술지

Circulating tumor cells (CTCs) are tumor cells that are separated from the primary site or metastatic lesion and disseminate in blood circulation. CTCs are considered to be part of the long process of cancer metastasis. As a 'liquid biopsy', CTC molecular examination and investigation of single cancer cells create an important opportunity for providing an understanding of cancer biology and the process of metastasis. In the last decade, we have seen dramatic development in defining the role of CTCs in lung cancer in terms of diagnosis, genomic alteration determination, treatment response and, finally, prognosis prediction. The aims of this review are to understand the basic biology and to review methods of detection of CTCs that apply to the various types of solid tumor. Furthermore, we explored clinical applications, including treatment monitoring to anticipate therapy resistance as well as biomarker analysis, in the context of lung cancer. We also explored the potential use of cell-free circulating tumor DNA (ctDNA) in the genomic alteration analysis of lung cancer.

Research progress of radiotherapy and molecular classifications of gastric cancer / 中国医师杂志

Adjuvant radiotherapy (RT) can improve the rate of loco-regional control for patients with gastric cancer (GC),while the selection of patients plays a key role.As the research moves along,several relatively comprehensive molecular classifications emerged such as the TCGA classification and the ACRG classification.Studies have demonstrated that molecular classifications are closely related to the clinicopathologic characteristics,prognosis and treatment response.However,there is not recognized molecular classification of GC presently.It is a great challenge for radiation oncologists to make use of the individual bioinformation and accurately select patients who would benefit from RT.Meanwhile,precision RT could also be achieved with the prediction of radiosensitivity,combination of RT with targeted therapy and the application of ctDNA within the field of RT.

Digital PCR analysis of plasma cell-free DNA for non-invasive detective of TKI targeted EGFR mutation in NSCLC patients / 中华检验医学杂志

It is important to analyze the epidermal growth factor receptor ( EGFR) mutation before makingstrategyonnon-small cell lung cancer ( NSCLC) patients scheduled to EGFR tyrosine kinase inhibitor ( TKI) therapy .Digital PCR is a new generation of molecular diagnostic technique that provides ultra-highersensitive, specific and absolute nucleic acid quantification based on its unique principle.The application of digital PCR indetecting circulate tumor DNA can be the truly tumorliquid biopsy, helps to acquire the accurate EGFR mutation status from peripheral blood and screen out the most appropriate patients for TKI therapy.This breakthrough technology will also contribute to tumor surveillance and drug resistance monitoring.

The combination of flow cytometry and automated cell image analyzer in determining the nature of ascites and pleural effusion nature / 中华检验医学杂志

Objective To explore the clinical value of flow cytometry( FCM) and DNA automated cell image analyzer ( AICM) in determine the character of ascites and pleural effusion.Methods This was a cross-sectional study.203 ascites and pleural effusionsamples were random selected from PLA hospital inpatients between August 2013 to June 2014 .The DNA content of sediment cells were detectedthrough the FCM and AICM respectively benign and malignant disease were differentiated according the counts and proportion of aneuploid cells.The sensitivity, specificitywere calculated byROC curves.Results The sensitivity, specificity and accuracy of flow cytometry cell in detectingtumor cells were 78.6%,80.0% and 79.2%%, while the sensitivity, specificity and accuracy of image analyzer were 83.5%,78.6% and 81. 3%respectively.When FCM and AICMwere combined ,the sensitivity, specificity and accuracyincreased to 92.2%, 86.3% and 89.6%.Conclusions Compared toconventional cytology test, the sensitivity and specificity were significantly high when the two methods were combined .Therefore, the combination method can be used to assist in clinical identification of the nature of ascites and pleural effusion and to help the diagnosis of disease.

¿Es posible utilizar las muestras de colecistectomías con cáncer en investigación?: Calidad del ADN de muestras obtenidas del sistema público y privado de salud / Quality of DNA from archival pathological samples of gallbladder cancer

Background: The quality of the archival samples stored at pathology services could be a limiting factor for molecular biology studies. Aim: To determine the quality of DNA extracted from gallbladder cancer samples at different institutions. Material and Methods: One hundred ninety four samples coming from fve medical centers in Chile, were analyzed. DNA extraction was quantifed determining genomic DNA concentration. The integrity of DNA was determined by polymerase chain reaction amplification of different length fragments of a constitutive gene (β-globin products of 110, 268 and 501 base pairs). Results: The mean DNA concentration obtained in 194 gallbladder cancer samples was 48 ± 43.1 ng/µl. In 22% of samples, no amplification was achieved despite obtaining a mean DNA concentration of 58.3 ng/ul. In 81, 67 and 22% of samples, a DNA amplification of at least 110, 268 or 501 base pairs was obtained, respectively. No differences in DNA concentration according to the source of the samples were demonstrated. However, there were marked differences in DNA integrity among participating centers. Samples from public hospitals were of lower quality than those from private clinics. Conclusions: Despite some limitations, in 80% of cases, the integrity of DNA in archival samples from pathology services in our country would allow the use of molecular biology techniques.

A correlation study on magnetic resonance imaging features and nuclear DNA contents in meningiomas / 肿瘤

Objective: To study the correlation of magnetic resonance imaging (MRI) features with the tumor nuclear DNA contents, and evaluate the biological behavior and proliferative potential of meningiomas using MRI. Methods: The DNA contents and the incidence of aneuploid of 45 patients with meningiomas were measured by means of photodensity method with image cytometry. The data were compared with MR findings for the statistical correlation analysis. Results: Tumors with the presence of peritumoral edema, irregular tumor shape, and ambiguous brain-tumor border had remarkable difference in DNA contents compared with those with negative peritumoral edema, smooth tumor shape, and clear brain-tumor border (P < 0.01). Using Spearman' s correlation coefficient analysis, we found a significant correlation (r = 0.696, P = 0.000) between three of MRI scores calculated for each patient and DNA contents. Conclusion: DNA contents and the incidence of aneuploid are higher in the tumors with the presence of peritumoral edema, irregular tumor shape, and ambiguous brain-tumor border. All of the imaging appearances can be used to estimate the proliferation potency and malignant biological behavior of the meningiomas.

Current trends in molecular classification of cancers / 中华检验医学杂志

Tumor morphology from the microscopic appearance has being served as the basis of tumor classification,but has serious 1imitations.Molecular aberrations,including DNA,RNA and protein,ale playing an ever increasing role in guiding classification,prognosis,and therapeutic strategies in cancer patients.A specific molecular profile correlating with important clinical parameters should allow physicians to base management decisions on the molecular characteristics of an individual patient's tumor.The application of high-throughput technologies to tumor,3 should make it possible to generate comprehensive molecular profiles.The integration of clinical,morphological and molecular data could result in a more precise classification of cancers,and lead to better understanding,individualized predicting and treatment,which would give the maximum benefit to the patients.