51
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Aguilar-Mahecha A, Joseph S, Cavallone L, Buchanan M, Krzemien U, Batist G, Basik M. Precision Medicine Tools to Guide Therapy and Monitor Response to Treatment in a HER-2+ Gastric Cancer Patient: Case Report. Front Oncol 2019; 9:698. [PMID: 31448226 PMCID: PMC6691136 DOI: 10.3389/fonc.2019.00698] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 07/15/2019] [Indexed: 12/18/2022] Open
Abstract
Trastuzumab, has played a major role in improving treatment outcomes in HER-2 positive gastric cancer. However, once there is disease progression there is a paucity of evidence for second line therapy. Patient-derived xenografts (PDXs) in combination with liquid biopsies can help guide individual therapeutic decisions and have now started to be studied. In the present case we established a PDX model from a metastatic HER-2+ gastric cancer patient and after the first engraftment passage we performed a mouse clinical trial to test T-DM1 as an alternative therapy for the patient. The PDX tumor response served as a guide to administer T-DM1 therapy to the patient who responded to treatment before relapsing 6 months later. Throughout out the clinical follow up of the patient, ctDNA levels of HER-2 copy number and a PIK3CA mutation were monitored and we found their correlation with drug response and disease progression to outperform that of CEA levels. This study highlights the utility of applying precision medicine tools combining PDX models to guide therapy with circulating tumor DNA (ctDNA) to monitor treatment response and disease progression.
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Affiliation(s)
| | - Sarah Joseph
- Segal Cancer Center, Jewish General Hospital, Montreal, QC, Canada
| | - Luca Cavallone
- Department of Oncology, Lady Davis Institute, McGill University, Montreal, QC, Canada
| | - Marguerite Buchanan
- Department of Oncology, Lady Davis Institute, McGill University, Montreal, QC, Canada
| | - Urszula Krzemien
- Department of Oncology, Lady Davis Institute, McGill University, Montreal, QC, Canada
| | - Gerald Batist
- Department of Oncology, Lady Davis Institute, McGill University, Montreal, QC, Canada.,Segal Cancer Center, Jewish General Hospital, Montreal, QC, Canada
| | - Mark Basik
- Department of Oncology, Lady Davis Institute, McGill University, Montreal, QC, Canada.,Department of Surgery, Jewish General Hospital, Montreal, QC, Canada
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52
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Feng W, Zong W, Li Y, Shen X, Cui X, Ju S. Abnormally expressed long noncoding RNA B3GALT5-AS1 may serve as a biomarker for the diagnostic and prognostic of gastric cancer. J Cell Biochem 2019; 121:557-565. [PMID: 31338903 DOI: 10.1002/jcb.29296] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Accepted: 06/27/2019] [Indexed: 12/12/2022]
Abstract
Early diagnosis of gastric cancer (GC) is an effective method to improve prognosis. Increasing number of long noncoding RNAs (lncRNAs) have been reported as biomarkers for several cancers. We aim to detect the level of lncRNA B3GALT5-AS1 and its association with clinical parameters and to further explore its application value in GC. We measured serum B3GALT5-AS1 expression in 107 patients with GC, 40 polyp patients, and 87 normal controls to explore the significance of serum B3GALT5-AS1 in GC using the quantitative real-time polymerase chain reaction method. The result demonstrated that B3GALT5-AS1 level was markedly richer in GC patients than that in normal people (P < .001). B3GALT5-AS1 may be served as a diagnostic marker for distinguishing GC patients from healthy people, and the proportion under the receiver operating characteristics curve is 0.816 (95% confidence interval, 0.758-0.874; P = .03). Further exploration validated that high serum B3GALT5-AS1 level was related to TNM stage (P = .024), and lymph node metastasis (P = .023). Our study suggested that serum B3GALT5-AS1 may be employed as an ideal biomarker for early screening of GC.
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Affiliation(s)
- Wei Feng
- Department of Laboratory Medicine, Affiliated Hospital of Nantong University, Nantong, China
| | - Wei Zong
- Department of Laboratory Medicine, Affiliated Hospital of Nantong University, Nantong, China
| | - Yi Li
- Department of Laboratory Medicine, Affiliated Hospital of Nantong University, Nantong, China
| | - Xianjuan Shen
- Clinical Medical Research Center, Affiliated Hospital of Nantong University, Nantong, China
| | - Xiaopeng Cui
- General Surgery Department, Affiliated Hospital of Nantong University, Nantong, China
| | - Shaoqing Ju
- Department of Laboratory Medicine, Affiliated Hospital of Nantong University, Nantong, China
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53
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Hechtman JF, Ross DS. The past, present, and future of HER2 (ERBB2) in cancer: Approaches to molecular testing and an evolving role in targeted therapy. Cancer Cytopathol 2019; 127:428-431. [PMID: 30938930 DOI: 10.1002/cncy.22124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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54
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Zeng C, Stroup EK, Zhang Z, Chiu BCH, Zhang W. Towards precision medicine: advances in 5-hydroxymethylcytosine cancer biomarker discovery in liquid biopsy. Cancer Commun (Lond) 2019; 39:12. [PMID: 30922396 PMCID: PMC6440138 DOI: 10.1186/s40880-019-0356-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 03/19/2019] [Indexed: 12/13/2022] Open
Abstract
Robust and clinically convenient biomarkers for cancer diagnosis, early detection, and prognosis have great potential to improve patient survival and are the key to precision medicine. The advent of next-generation sequencing technologies enables a more sensitive and comprehensive profiling of genetic and epigenetic information in tumor-derived materials. Researchers are now able to monitor the dynamics of tumorigenesis in new dimensions, such as using circulating cell-free DNA (cfDNA) and tumor DNA (ctDNA). Mutation-based assays in liquid biopsy cannot always provide consistent results across studies due partly to intra- and inter-tumoral heterogeneity as well as technical limitations. In contrast, epigenetic analysis of patient-derived cfDNA is a promising alternative, especially for early detection and disease surveillance, because epigenetic modifications are tissue-specific and reflect the dynamic process of cancer progression. Therefore, cfDNA-based epigenetic assays are emerging to be a highly sensitive, minimally invasive tool for cancer diagnosis and prognosis with great potential in future precise care of cancer patients. The major obstacle for applying epigenetic analysis of cfDNA, however, has been the lack of enabling techniques with high sensitivity and technical robustness. In this review, we summarized the advances in epigenome-wide profiling of 5-hydroxymethylcytosine (5hmC) in cfDNA, focusing on the detection approaches and potential role as biomarkers in different cancer types.
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Affiliation(s)
- Chang Zeng
- Driskill Graduate Program in Life Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Emily Kunce Stroup
- Driskill Graduate Program in Life Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Zhou Zhang
- Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, 680 N. Lake Shore Dr., Suite 1400, Chicago, IL, 60611, USA
| | - Brian C-H Chiu
- Department of Public Health Sciences, University of Chicago, Chicago, IL, 60637, USA
| | - Wei Zhang
- Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, 680 N. Lake Shore Dr., Suite 1400, Chicago, IL, 60611, USA. .,The Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA. .,Institute of Precision Medicine, Jining Medical University, Jining, 272067, Shandong, P. R. China.
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55
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Koessler T, Addeo A, Nouspikel T. Implementing circulating tumor DNA analysis in a clinical laboratory: A user manual. Adv Clin Chem 2019; 89:131-188. [PMID: 30797468 DOI: 10.1016/bs.acc.2018.12.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Liquid biopsy, the analysis of cell-free circulating tumor DNA (ctDNA), is becoming one of the most promising tools in oncology. It has already shown its usefulness in selecting and modulating therapy via remote analysis of the tumor genome and holds important promises in cancer therapy and management, such as assessing the success of key therapeutic steps, monitoring residual disease, early detection of relapses, and establishing prognosis. Yet, ctDNA analysis is technically challenging and its implementation in the laboratory raises multiple strategic and practical issues. As for oncology clinics, integration of this novel test in well-established therapeutic protocols can also pose numerous questions. The current review is intended as a field guide for (1) diagnostic laboratories wishing to implement, validate and possibly accredit ctDNA testing and (2) clinical oncologists interested in integrating the various applications of liquid biopsies in their daily practice. We provide advice and practical recommendations based on our own experience with the technical validations of these methods and on a review of the current literature, with a focus toward gastro-intestinal, lung and breast cancers.
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Affiliation(s)
- Thibaud Koessler
- Department of Oncology, Geneva University Hospital, Geneva, Switzerland
| | - Alfredo Addeo
- Department of Oncology, Geneva University Hospital, Geneva, Switzerland
| | - Thierry Nouspikel
- Service of Medical Genetics, Diagnostics Department, Geneva University Hospital, Geneva, Switzerland.
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56
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Pan G, Li D, Li X, Peng Y, Wang T, Zuo C. SPECT/CT imaging of HER2 expression in colon cancer-bearing nude mice using 125I-Herceptin. Biochem Biophys Res Commun 2018; 504:765-770. [PMID: 30217443 DOI: 10.1016/j.bbrc.2018.08.201] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 08/31/2018] [Indexed: 02/07/2023]
Abstract
An accurate assessment of HER2 status in patients with colorectal cancer is very important, because only the patients overexpressing HER2 can benefit most from the anti-HER2 targeted therapy. In this study, we investigated the feasibility of detecting HER2 expression in colon cancer by SPECT imaging using 125I-Herceptin, which showed high labeling rate, good in vitro stability and high binding specificity for HER2. HER2-positive mouse colon adenocarcinoma cell line (MC 38) was chosen as the colon caner cell model, and used for the establishment of colon cancer-bearing nude mice model. SPECT/CT imaging suggested that the tumors can be visualized at 12 h after the injection of 125I-Herceptin, and the uptake of tracer in tumors reached the peak at 24 h after injection, and can be attenuated significantly by pretreatment with an excess of nonlabeled Herceptin. These results indicates that 125I-Herceptin can be considered as an effective SPECT probe for the non-invasive detection of HER2 expression in colon cancer.
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Affiliation(s)
- Guixia Pan
- Department of Nuclear Medicine, Changhai Hospital, The Second Military Medical University, Shanghai, 200433, China
| | - Danni Li
- Department of Nuclear Medicine, Changhai Hospital, The Second Military Medical University, Shanghai, 200433, China
| | - Xiao Li
- Department of Nuclear Medicine, Changhai Hospital, The Second Military Medical University, Shanghai, 200433, China
| | - Ye Peng
- Department of Nuclear Medicine, Changhai Hospital, The Second Military Medical University, Shanghai, 200433, China
| | - Tao Wang
- Department of Nuclear Medicine, Changhai Hospital, The Second Military Medical University, Shanghai, 200433, China.
| | - Changjing Zuo
- Department of Nuclear Medicine, Changhai Hospital, The Second Military Medical University, Shanghai, 200433, China.
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57
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Raimondi A, Nichetti F, Peverelli G, Di Bartolomeo M, De Braud F, Pietrantonio F. Genomic markers of resistance to targeted treatments in gastric cancer: potential new treatment strategies. Pharmacogenomics 2018; 19:1047-1068. [PMID: 30041572 DOI: 10.2217/pgs-2018-0077] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Gastric cancer is a highly heterogeneous disease, displaying a complex genomic landscape and an unfavorable outcome with standard therapies. Based on distinctive genomic alterations, novel targeted agents have been developed with the aim of personalizing treatments and improving patient outcome. However, a subgroup of patients is primarily treatment-resistant, and even in the initially sensitive population, secondary resistance emerges, thus limiting therapeutic benefit. In this review, we summarize the clinical data about standard targeted agents in gastric cancer, specifically anti-HER2 treatments and antivascular therapies. We also illustrate the available evidence regarding molecular mechanisms of resistance to these agents and we discuss potential strategies for new targeted treatments that could overcome such resistance.
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Affiliation(s)
- Alessandra Raimondi
- Medical Oncology Department, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | - Federico Nichetti
- Medical Oncology Department, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | - Giorgia Peverelli
- Medical Oncology Department, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | - Maria Di Bartolomeo
- Medical Oncology Department, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | - Filippo De Braud
- Medical Oncology Department, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.,Department of Oncology & Hemato-oncology, University of Milan, Italy
| | - Filippo Pietrantonio
- Medical Oncology Department, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.,Department of Oncology & Hemato-oncology, University of Milan, Italy
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58
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Saluja H, Karapetis CS, Pedersen SK, Young GP, Symonds EL. The Use of Circulating Tumor DNA for Prognosis of Gastrointestinal Cancers. Front Oncol 2018; 8:275. [PMID: 30087854 PMCID: PMC6066577 DOI: 10.3389/fonc.2018.00275] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Accepted: 07/02/2018] [Indexed: 01/10/2023] Open
Abstract
Gastrointestinal cancers, including oesophageal, gastric and colorectal cancers (CRC) have high rates of disease recurrence despite curative resection. There are a number of recent studies that have investigated the use of circulating tumor DNA (ctDNA) for prognostic value in these cancers. We reviewed studies that had been published prior to March 2018 that assessed the prognostic values of ctDNA in patients with oesophageal and gastric cancers, gastrointestinal stromal tumors (GIST) and CRC. We identified 63 eligible clinical studies that focussed on recurrence and survival. Studies assessed investigated various ctDNA biomarkers in patients with different stages of cancer undergoing surgical resection, chemotherapy and no treatment. For oesophageal squamous cell carcinoma and oesophageal adenocarcinoma, methylation of certain genes such as APC and DAPK have been highlighted as promising biomarkers for prognostication, but these studies are limited and more comprehensive research is needed. Studies focusing on gastric cancer patients showed that methylation of ctDNA in SOX17 and APC were independently associated with poor survival. Two studies demonstrated an association between ctDNA and recurrence and survival in GIST patients, but more studies are needed for this type of gastrointestinal cancer. A large proportion of the literature was on CRC which identified both somatic mutations and DNA methylation biomarkers to determine prognosis. ctDNA biomarkers that identified somatic mutations were more effective if they were personalized based on mutations found in the primary tumor tissue, but ctDNA methylation studies identified various biomarkers that predicted increased risk of recurrence, poor disease free survival and overall survival. While the use of non-invasive ctDNA biomarkers for prognosis is promising, larger studies are needed to validate the clinical utility for optimizing treatment and surveillance strategies to reduce mortality from gastrointestinal cancers.
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Affiliation(s)
- Hariti Saluja
- Flinders Centre for Innovation in Cancer, College of Medicine and Public Health, Flinders University, Bedford Park, SA, Australia.,Department of Medicine, College of Medicine and Public Health, Flinders University, Bedford Park, SA, Australia
| | - Christos S Karapetis
- Flinders Centre for Innovation in Cancer, College of Medicine and Public Health, Flinders University, Bedford Park, SA, Australia.,Department of Oncology, Flinders Medical Centre, Bedford Park, SA, Australia
| | | | - Graeme P Young
- Flinders Centre for Innovation in Cancer, College of Medicine and Public Health, Flinders University, Bedford Park, SA, Australia
| | - Erin L Symonds
- Flinders Centre for Innovation in Cancer, College of Medicine and Public Health, Flinders University, Bedford Park, SA, Australia.,Bowel Health Service, Flinders Medical Centre, Bedford Park, SA, Australia
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59
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Battaglin F, Naseem M, Puccini A, Lenz HJ. Molecular biomarkers in gastro-esophageal cancer: recent developments, current trends and future directions. Cancer Cell Int 2018; 18:99. [PMID: 30008616 PMCID: PMC6042434 DOI: 10.1186/s12935-018-0594-z] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 06/28/2018] [Indexed: 12/12/2022] Open
Abstract
Gastro-esophageal adenocarcinomas (GEA) represent a severe global health burden and despite improvements in the multimodality treatment of these malignancies the prognosis of patients remains poor. HER2 overexpression/amplification has been the first predictive biomarker approved in clinical practice to guide patient selection for targeted treatment with trastuzumab in advanced gastric and gastro-esophageal junction cancers. More recently, immunotherapy has been approved for the treatment of GEA and PD-L1 expression is now a biomarker required for the administration of pembrolizumab in these diseases. Significant progress has been made in recent years in dissecting the genomic makeup of GEA in order to identify distinct molecular subtypes linked to distinct patterns of molecular alterations. GEA have been found to be highly heterogeneous malignances, representing a challenge for biomarkers discovery and targeted treatment development. The current review focuses on an overview of established and novel promising biomarkers in GEA, covering recent molecular classifications from TCGA and ACRG. Main elements of molecular heterogeneity are discussed, as well as emerging mechanisms of primary and secondary resistance to HER2 targeted treatment and recent biomarker-driven trials. Future perspectives on the role of epigenetics, miRNA/lncRNA and liquid biopsy, and patient-derived xenograft models as a new platform for molecular-targeted drug discovery in GEA are presented. Our knowledge on the genomic landscape of GEA continues to evolve, uncovering the high heterogeneity and deep complexity of these tumors. The availability of new technologies and the identification of promising novel biomarker will be critical to optimize targeted treatment development in a setting where therapeutic options are currently lacking. Nevertheless, clinical validation of novel biomarkers and treatment strategies still represents an issue.
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Affiliation(s)
- Francesca Battaglin
- Division of Medical Oncology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, 1441 Eastlake Avenue, Suite 5410, Los Angeles, CA 90033 USA
- Medical Oncology Unit 1, Clinical and Experimental Oncology Department, Veneto Institute of Oncology IOV-IRCCS, 35128 Padua, Italy
| | - Madiha Naseem
- Division of Medical Oncology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, 1441 Eastlake Avenue, Suite 5410, Los Angeles, CA 90033 USA
| | - Alberto Puccini
- Division of Medical Oncology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, 1441 Eastlake Avenue, Suite 5410, Los Angeles, CA 90033 USA
- Oncologia Medica 1, Ospedale Policlinico San Martino, 16132 Genoa, Italy
| | - Heinz-Josef Lenz
- Division of Medical Oncology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, 1441 Eastlake Avenue, Suite 5410, Los Angeles, CA 90033 USA
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60
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Wu X, Zhu L, Ma PC. Next-Generation Novel Noninvasive Cancer Molecular Diagnostics Platforms Beyond Tissues. Am Soc Clin Oncol Educ Book 2018; 38:964-977. [PMID: 30231325 PMCID: PMC6381937 DOI: 10.1200/edbk_199767] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
In recent years, there has been a revolutionary expansion in technologic advances and therapeutic innovations in cancer medicine. Cancer diagnostics has begun to move away from a sole dependence on direct tumor tissue biopsy for cancer detection, diagnosis, and treatment monitoring. The need for improvement in molecular cancer diagnostics has never been more important, with not only the advent of cancer genomics and genomics-guided precision medicine but also the recent arrival of cancer immunotherapies. Owing to the practical limitations and risks associated with tissue-based biopsy diagnostics, novel noninvasive cancer diagnostics platforms have continued to evolve and expand in recent years. Examples of these platforms include the liquid biopsy, which is used to interrogate ctDNA or circulating tumor cells, proteomics, metabolomics, and exosomes; the urine biopsy, which is used to assay ctDNAs; saliva and stool biopsies, which are used for molecular genomics assays; and the breath biopsy, which measures volatile organic compounds. These next-generation noninvasive molecular diagnostics assays beyond tissues fundamentally transform the potential utilities of cancer diagnostics to enable repeat, prospective, and serial longitudinal "biopsies" to monitor disease response resistance and progression on therapies. Moreover, they allow continual interrogation and molecular in-depth analysis of the evolving tumor's pan-canceromics under therapeutic stress. These technological and diagnostic advances have already brought about paradigm-changing next-generation cancer therapeutic strategies to enhance overall treatment efficacies. This article reviews the key noninvasive next-generation molecular diagnostics platforms beyond tissues, with emphasis on clinical utilities and applications.
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Affiliation(s)
- Xiaoliang Wu
- From the West Virginia University Cancer Institute, West Virginia University Medicine, West Virginia University, Morgantown, WA; West Virginia Clinical and Translational Institute, Morgantown, WV
| | - Lin Zhu
- From the West Virginia University Cancer Institute, West Virginia University Medicine, West Virginia University, Morgantown, WA; West Virginia Clinical and Translational Institute, Morgantown, WV
| | - Patrick C Ma
- From the West Virginia University Cancer Institute, West Virginia University Medicine, West Virginia University, Morgantown, WA; West Virginia Clinical and Translational Institute, Morgantown, WV
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61
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Detection of HER2 amplification in formalin-fixed paraffin-embedded breast carcinoma tissue with digital PCR using two TFF3 sequences as internal reference. Exp Mol Pathol 2018; 104:235-238. [PMID: 29715436 DOI: 10.1016/j.yexmp.2018.04.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Revised: 03/30/2018] [Accepted: 04/27/2018] [Indexed: 02/06/2023]
Abstract
PURPOSE Droplet digital PCR (ddPCR) is a highly accurate method to determine DNA concentration and detect copy number variations. We developed an approach to assess HER2 gene amplification status using ddPCR with two sequences of TFF3 as reference probes. EXPERIMENTAL DESIGN 76 templates of carcinoma DNA were prepared from formalin-fixed paraffin-embedded (FFPE) tissues. Digital PCR assay of the copy number of HER2 and TFF3 DNA was performed on the samples. The results were compared to prior fluorescent in-situ hybridation (FISH) assays performed on the same samples. RESULTS The ddPCR assay had high concordance with the conventionally used immunohistochemistry (IHC) and FISH methods. The ddPCR method returned fewer indeterminate results than IHC. Concordance between a ddPCR plus FISH method and IHC plus FISH can rise to 98.7% (75/76) after validation is carried out. CONCLUSION It's potentially possible to improve the sensitivity and specifity of HER2 ddPCR assays using reference sequences not co-localized with HER2 on chromosome 17, and combining results from multiple sequences. Adopting an approach based on ddPCR HER2 assays plus FISH could lead to reduced costs, labour, and time consumption compared to current IHC plus FISH standard, while not losing precision.
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