Cancer is a common cause of death worldwide.Despite significant advances in cancer treatments,the morbidity and mortality are still enormous.Tumor heterogeneity,especially intratumoral heterogeneity,is a significant r...Cancer is a common cause of death worldwide.Despite significant advances in cancer treatments,the morbidity and mortality are still enormous.Tumor heterogeneity,especially intratumoral heterogeneity,is a significant reason underlying difficulties in tumor treatment and failure of a number of current therapeutic modalities,even of molecularly targeted therapies.The development of a virtually noninvasive "liquid biopsy" from the blood has been attempted to characterize tumor heterogeneity.This review focuses on cell-free circulating tumor DNA(ctDNA) in the bloodstream as a versatile biomarker.ctDNA analysis is an evolving field with many new methods being developed and optimized to be able to successfully extract and analyze ctDNA,which has vast clinical applications.ctDNA has the potential to accurately genotype the tumor and identify personalized genetic and epigenetic alterations of the entire tumor.In addition,ctDNA has the potential to accurately monitor tumor burden and treatment response,while also being able to monitor minimal residual disease,reducing the need for harmful adjuvant chemotherapy and allowing more rapid detection of relapse.There are still many challenges that need to be overcome prior to this biomarker getting wide adoption in the clinical world,including optimization,standardization,and large multicenter trials.展开更多
Precision medicine for cancer patients aims to adopt the most suitable treatment options during diagnosis and treatment of individuals. Detecting circulating tumor cell （CTC） or circulating tumor DNA （ctDNA） in pl...Precision medicine for cancer patients aims to adopt the most suitable treatment options during diagnosis and treatment of individuals. Detecting circulating tumor cell （CTC） or circulating tumor DNA （ctDNA） in plasma or serum could serve as liquid biopsy, which would be useful for numerous diagnostic applications. Liquid biopsies can help clinicians screen and detect cancer early, stratify patients to the most suitable treatment and real-time monitoring of treatment response and resistance mechanisms in the tumor, evaluate the risk for metastatic relapse, and estimate prognosis. We summarized the advantages and disadvantages of tissue and liquid biopsies. We also further compared and analyzed the advantages and limitations of detecting CTCs, ctDNAs, and exosomes. Furthermore, we reviewed the literature related with the application of serum or plasma CTCs, ctDNAs, and exosomes for diagnosis and prognosis of cancer. We also analyzed their opportunities and challenges as future biomarkers. In the future, liquid biopsies could be used to guide cancer treatment. They could also provide the ideal scheme to personalize treatment in precision medicine.展开更多
The role of liver biopsy in the diagnosis of hepatocellular carcinoma(HCC)has been challenged over time by the ability of imaging techniques to characterize liver lesions in patients with known cirrhosis.In fact,in th...The role of liver biopsy in the diagnosis of hepatocellular carcinoma(HCC)has been challenged over time by the ability of imaging techniques to characterize liver lesions in patients with known cirrhosis.In fact,in the diagnostic algorithm for this tumor,histology is currently relegated to controversial cases.Furthermore,the risk of complications,such as tumor seeding and bleeding,as well as inadequate sampling have further limited the use of liver biopsy for HCC management.However,there is growing evidence of prognostic and therapeutic information available from microscopic and molecular analysis of HCC and,as the information content of the tissue sample increases,the advantages of liver biopsy might modify the current risk/benefit ratio.We herein review the role and potentiality of liver biopsy in the diagnosis and management of HCC.As the potentiality of precision medicine comes to the management of HCC,it will be crucial to have rapid pathways to define prognosis,and even treatment,by identifying the patients who could most benefit from target-driven therapies.All of the above reasons suggest that the current role of liver biopsy in the management of HCC needs substantial reconsideration.展开更多
Gastrointestinal stromal tumors(GISTs) have been recognized as a biologically distinctive type of tumor,different from smooth muscle and neural tumors of the gastrointestinal tract.The identification of genetic aberra...Gastrointestinal stromal tumors(GISTs) have been recognized as a biologically distinctive type of tumor,different from smooth muscle and neural tumors of the gastrointestinal tract.The identification of genetic aberrations in proto-oncogenes that drive the growth of GISTs is critical for improving the efficacy of cancer therapy by matching targeted drugs to specific mutations.Research into the oncogenic mechanisms of GISTs has found that these tumors frequently contain activating gene mutations in either platelet-derived growth factor receptor A(PDGFRA) or a receptor tyrosine protein associated with a mast cell growth factor receptor encoded by the KIT gene.Mutant cancer subpopulations have the potential to disrupt durable patient responses to molecularly targeted therapy for GISTs,yet the prevalence and size of subpopulations remain largely unexplored.Detection of the cancer subpopulations that harbor low-frequency mutant alleles of target proto-oncogenes through the use of molecular genetic methods,such as polymerase chain reaction(PCR) target amplification technology,is hampered by the high abundance of wildtype alleles,which limit the sensitivity of detection of these minor mutant alleles.This is especially true in the case of mutant tumor DNA derived "driver" and "drug-resistant" alleles that are present in the circulating cell-free tumor DNA(cfDNA) in the peripheral blood circulation of GIST patients.So-called "liquid biopsy" allows for the dynamic monitoring of the patients' tumor status during treatment using minimally invasive sampling.New methodologies,such as a technology that employs a xenonucleic acid(XNA) clamping probe to block the PCR amplification of wild-type templates,have allowed improved molecular detection of these low-frequency alleles both in tissue biopsy samples and in cfDNA.These new methodologies could be widely applied for minimally invasive molecular testing in the therapeutic management of GISTs.展开更多
Despite recent advances in surgical techniques and perioperative management, the prognosis of pancreatic cancer(PCa) remains extremely poor. To provide optimal treatment for each patient with Pca, superior biomarkers ...Despite recent advances in surgical techniques and perioperative management, the prognosis of pancreatic cancer(PCa) remains extremely poor. To provide optimal treatment for each patient with Pca, superior biomarkers are urgently needed in all phases of management from early detection to staging, treatment monitoring, and prognosis. In the blood of patients with cancer, circulating tumor cells(CTCs) and cell-free nucleic acids(cf NAs), such as DNA, m RNA, and noncoding RNA have been recognized. In the recent years, their presence in the blood has encouraged researchers to investigate their potential use as novel blood biomarkers, and numerous studies have demonstrated their potential clinical utility as a biomarker for certain types of cancer. This concept, called "liquid biopsy" has been focused on as a less invasive, alternative approach to cancer tissue biopsy for obtaining genetic and epigenetic aberrations that contribute to oncogenesis and cancer progression. In this article, we review the available literature on CTCs and cfN As in patients with cancer, particularly focusing on PCa, and discuss future perspectives in this field.展开更多
基金supported partly by the National Natural Science Foundation of China(No.81227901)the Natural Science Basic Research Plan in Shaanxi Province of China(No.2015JZ019)+1 种基金the Fundamental Research Funds for the Central Universities,National Cancer Institute of the National Institutes of Health(No.R00CA138914)National Natural Science Foundation(No. 81372216)
文摘Cancer is a common cause of death worldwide.Despite significant advances in cancer treatments,the morbidity and mortality are still enormous.Tumor heterogeneity,especially intratumoral heterogeneity,is a significant reason underlying difficulties in tumor treatment and failure of a number of current therapeutic modalities,even of molecularly targeted therapies.The development of a virtually noninvasive "liquid biopsy" from the blood has been attempted to characterize tumor heterogeneity.This review focuses on cell-free circulating tumor DNA(ctDNA) in the bloodstream as a versatile biomarker.ctDNA analysis is an evolving field with many new methods being developed and optimized to be able to successfully extract and analyze ctDNA,which has vast clinical applications.ctDNA has the potential to accurately genotype the tumor and identify personalized genetic and epigenetic alterations of the entire tumor.In addition,ctDNA has the potential to accurately monitor tumor burden and treatment response,while also being able to monitor minimal residual disease,reducing the need for harmful adjuvant chemotherapy and allowing more rapid detection of relapse.There are still many challenges that need to be overcome prior to this biomarker getting wide adoption in the clinical world,including optimization,standardization,and large multicenter trials.
文摘Precision medicine for cancer patients aims to adopt the most suitable treatment options during diagnosis and treatment of individuals. Detecting circulating tumor cell （CTC） or circulating tumor DNA （ctDNA） in plasma or serum could serve as liquid biopsy, which would be useful for numerous diagnostic applications. Liquid biopsies can help clinicians screen and detect cancer early, stratify patients to the most suitable treatment and real-time monitoring of treatment response and resistance mechanisms in the tumor, evaluate the risk for metastatic relapse, and estimate prognosis. We summarized the advantages and disadvantages of tissue and liquid biopsies. We also further compared and analyzed the advantages and limitations of detecting CTCs, ctDNAs, and exosomes. Furthermore, we reviewed the literature related with the application of serum or plasma CTCs, ctDNAs, and exosomes for diagnosis and prognosis of cancer. We also analyzed their opportunities and challenges as future biomarkers. In the future, liquid biopsies could be used to guide cancer treatment. They could also provide the ideal scheme to personalize treatment in precision medicine.
文摘The role of liver biopsy in the diagnosis of hepatocellular carcinoma(HCC)has been challenged over time by the ability of imaging techniques to characterize liver lesions in patients with known cirrhosis.In fact,in the diagnostic algorithm for this tumor,histology is currently relegated to controversial cases.Furthermore,the risk of complications,such as tumor seeding and bleeding,as well as inadequate sampling have further limited the use of liver biopsy for HCC management.However,there is growing evidence of prognostic and therapeutic information available from microscopic and molecular analysis of HCC and,as the information content of the tissue sample increases,the advantages of liver biopsy might modify the current risk/benefit ratio.We herein review the role and potentiality of liver biopsy in the diagnosis and management of HCC.As the potentiality of precision medicine comes to the management of HCC,it will be crucial to have rapid pathways to define prognosis,and even treatment,by identifying the patients who could most benefit from target-driven therapies.All of the above reasons suggest that the current role of liver biopsy in the management of HCC needs substantial reconsideration.
文摘Gastrointestinal stromal tumors(GISTs) have been recognized as a biologically distinctive type of tumor,different from smooth muscle and neural tumors of the gastrointestinal tract.The identification of genetic aberrations in proto-oncogenes that drive the growth of GISTs is critical for improving the efficacy of cancer therapy by matching targeted drugs to specific mutations.Research into the oncogenic mechanisms of GISTs has found that these tumors frequently contain activating gene mutations in either platelet-derived growth factor receptor A(PDGFRA) or a receptor tyrosine protein associated with a mast cell growth factor receptor encoded by the KIT gene.Mutant cancer subpopulations have the potential to disrupt durable patient responses to molecularly targeted therapy for GISTs,yet the prevalence and size of subpopulations remain largely unexplored.Detection of the cancer subpopulations that harbor low-frequency mutant alleles of target proto-oncogenes through the use of molecular genetic methods,such as polymerase chain reaction(PCR) target amplification technology,is hampered by the high abundance of wildtype alleles,which limit the sensitivity of detection of these minor mutant alleles.This is especially true in the case of mutant tumor DNA derived "driver" and "drug-resistant" alleles that are present in the circulating cell-free tumor DNA(cfDNA) in the peripheral blood circulation of GIST patients.So-called "liquid biopsy" allows for the dynamic monitoring of the patients' tumor status during treatment using minimally invasive sampling.New methodologies,such as a technology that employs a xenonucleic acid(XNA) clamping probe to block the PCR amplification of wild-type templates,have allowed improved molecular detection of these low-frequency alleles both in tissue biopsy samples and in cfDNA.These new methodologies could be widely applied for minimally invasive molecular testing in the therapeutic management of GISTs.
文摘Despite recent advances in surgical techniques and perioperative management, the prognosis of pancreatic cancer(PCa) remains extremely poor. To provide optimal treatment for each patient with Pca, superior biomarkers are urgently needed in all phases of management from early detection to staging, treatment monitoring, and prognosis. In the blood of patients with cancer, circulating tumor cells(CTCs) and cell-free nucleic acids(cf NAs), such as DNA, m RNA, and noncoding RNA have been recognized. In the recent years, their presence in the blood has encouraged researchers to investigate their potential use as novel blood biomarkers, and numerous studies have demonstrated their potential clinical utility as a biomarker for certain types of cancer. This concept, called "liquid biopsy" has been focused on as a less invasive, alternative approach to cancer tissue biopsy for obtaining genetic and epigenetic aberrations that contribute to oncogenesis and cancer progression. In this article, we review the available literature on CTCs and cfN As in patients with cancer, particularly focusing on PCa, and discuss future perspectives in this field.
