• Journal of Gastric Cancer
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• v.24 no.1
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• pp.4-28
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• 2024

Liquid biopsy, a minimally invasive procedure that causes minimal pain and complication risks to patients, has been extensively studied for cancer diagnosis and treatment. Moreover, it facilitates comprehensive quantification and serial assessment of the whole-body tumor burden. Several biosources obtained through liquid biopsy have been studied as important biomarkers for establishing early diagnosis, monitoring minimal residual disease, and predicting the prognosis and response to treatment in patients with cancer. Although the clinical application of liquid biopsy in gastric cancer is not as robust as that in other cancers, biomarker studies using liquid biopsy are being actively conducted in patients with gastric cancer. Herein, we aimed to review the role of various biosources that can be obtained from patients with gastric cancer through liquid biopsies, such as blood, saliva, gastric juice, urine, stool, peritoneal lavage fluid, and ascites, by dividing them into cellular and acellular components. In addition, we reviewed previous studies on the diagnostic, prognostic, and predictive biomarkers for gastric cancer using liquid biopsy and discussed the limitations of liquid biopsy and the challenges to overcome these limitations in patients with gastric cancer.

• Journal of Digestive Cancer Reports
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• v.8 no.1
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• pp.56-60
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• 2020

In recent years, liquid biopsy has received immense attention. Liquid biopsy is a minimally invasive method used for obtaining biological fluids including urine, pleural fluid and, mostly, peripheral blood. Liquid biopsy involves various targets including circulating tumors cells (CTCs), circulating cell-free tumor DNA (ctDNA), and microRNA (miRNA). Colorectal cancer (CRC), like other solid tumors, shed tumor cells into the bloodstream. Analysis of these CTCs, as well as ctDNA is the primary objective of the liquid biopsy. Evaluation of CTC or ctDNA offers information about early tumor release, development of tumor metastasis and also about mechanisms involved in tumor resistance to treatment.

• Genomics & Informatics
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• v.15 no.1
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• pp.48-50
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• 2017

Tumor tissues from biopsies or surgery are major sources for the next generation sequencing (NGS) study, but these procedures are invasive and have limitation to overcome intratumor heterogeneity. Recent studies have shown that driver alterations in tumor tissues can be detected by liquid biopsy which is a less invasive technique capable of both capturing the tumor heterogeneity and overcoming the difficulty in tissue sampling. However, it is still unclear whether the driver alterations in liquid biopsy can be detected by targeted NGS and how those related to the tissue biopsy. In this study, we performed whole-exome sequencing for a breast cancer tissue and identified PTEN p.H259fs*7 frameshift mutation. In the plasma DNA (liquid biopsy) analysis by targeted NGS, the same variant initially identified in the tumor tissue was also detected with low variant allele frequency. This mutation was subsequently validated by digital polymerase chain reaction in liquid biopsy. Our result confirm that driver alterations identified in the tumor tissue were detected in liquid biopsy by targeted NGS as well, and suggest that a higher depth of sequencing coverage is needed for detection of genomic alterations in a liquid biopsy.

• Proceedings of the Korea Contents Association Conference
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• 2019.05a
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• pp.469-470
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• 2019

차세대염기서열분석법(NGS, Next Generation Sequencing) 기술은 하나의 유전체를 무수히 많은 조각으로 분해하여 각 조각을 동시에 읽어낸 뒤, 전산기술을 이용하여 조합함으로써 방대한 유전체 정보를 빠르게 해독하는 방법이다. 한편, 액체 생검(LB, liquid biopsy)이란 암세포가 깨지면서 생기는 미량의 DNA 조각을 말초혈액 속에서 찾아내 암을 진단하는 기술로 조직 생검(tissue biopsy)에 비해 비침습적이다. 본 논문은 NGS와 LB 기술을 접목했을 때 확진이 가능하고 예후 및 치료경과의 예측이 가능함을 제언하였다.

• Design & Manufacturing
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• v.17 no.1
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• pp.20-26
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• 2023

Lab-on-a-disc is a circular disc shape of cartridge that can be used for blood-based liquid biopsy to diagnose an early stage of cancer. Currently, liquid biopsies are regarded as a time-consuming process, and require sophisticated skills to precisely separate cell-free DNA (cfDNA) and circulating tumor cells (CTCs) floating in the bloodstream for accurate diagnosis. However, by applying the lab-on-a-disc to liquid biopsy, the entire process can be operated automatically. To do so, the lab-on-a-disc should be designed to prevent blood leakage during the centrifugation, transport, and dilution of blood inside the lab-on-a-disc in the process of liquid biopsy. In this study, the main components of lab-on-a-disc for liquid biopsy are fabricated by injection molding for mass production, and ultrasonic welding is employed to ensure the bonding strength between the components. To guarantee accurate ultrasonic welding, the flatness of the components is optimized numerically by using the response surface methodology with four main injection molding processing parameters, including the mold & resin temperatures, the injection speed, and the packing pressure. The 27 times finite element analyses using Moldflow® reveal that the injection time and the packing pressure are the critical factors affecting the flatness of the components with an optimal set of values for all four processing parameters. To further improve the flatness of the lab-on-a-disc components for stable mass production, a quarter-disc shape of lab-on-a-disc with a radius of 75 mm is used instead of a full circular shape of the disc, and this significantly decreases the standard deviation of flatness to 30% due to the reduced overall length of the injection molded components by one-half. Moreover, it is also beneficial to use a quarter disc shape to manage the deviation of flatness under 3 sigma limits.

• The Korean journal of helicobacter and upper gastrointestinal research
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• v.18 no.3
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• pp.150-156
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• 2018

Precision medicine stands for 4Ps - precise, preventive, participatory, and personal; in which "precision" is important because the current modern medicine starts from "trial and error," and "one does not fit all". Current targeted therapies for cancer have changed treatment approaches and led the precision medicine; however, clinical use of liquid biopsy, using blood or other liquid specimens to characterize circulating tumor cells (CTC) or tumor genes instead of biopsies of tumor tissues, still awaits availability of more information regarding non-invasive cancer detection and characterization, prediction of treatment response, monitoring the disease course and relapse possibilities, identification of mechanisms of drug resistance, and newer pathogenesis. In this review, we will introduce the basic concept of CTC, circulating cell free DNA, and exosomes and their possible application for gastric cancer relevant with Helicobacter pylori infection.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.16
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• pp.7271-7275
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• 2015

The objective of this study was to determine the prevalence of significant lesions defined as high grade squamous intraepithelial lesions (HSIL), adenocarcinoma in situ (AIS) and invasive carcinoma in women who had HPV-positive and cytology negative co-testing screening results. This retrospective study was conducted in Chiang Mai University Hospital between May, 2013 and August, 2014. Hybrid capture 2 (HC2) was used for HPV testing and conventional Pap smears for cytologic screening. A repeat liquid-based cytology (LBC) was performed in women with such co-testing results followed by colposcopy. Random biopsy was performed in cases of normal colposcopic findings. Further investigations were carried out according to the biopsy or the repeat LBC results. During the study period, 273 women met the criteria and participated in the study. The mean age of these women was 46.4 years with 30% of them reporting more than one partner. The median interval time to colposcopy was 165 days. About 40% showed an abnormality in the repeat cytology. Significant cervical lesions were found in 20 (7.3%) women, including 2 invasive cancers. Of interest was that only 2 of 20 significant lesions were diagnosed by colposcopic examination while the remainder were initially detected by cervical biopsy and abnormal repeat cytology. In conclusion, the prevalence of significant cervical lesions in HPV positive and cytology negative women in Northern Thailand was 7.3%. Further diagnostic work up with repeat cytology follow by colposcopy is recommended. Random biopsy should be performed even when the colposcopic findings are normal.

• Tuberculosis and Respiratory Diseases
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• v.83 no.1
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• pp.61-70
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• 2020

Background: Circulating tumor cells (CTCs) are frequently detected in patients with advanced-stage malignant tumors and could act as a predictor of poor prognosis. However, there is a paucity of data on the relationship between CTC number and primary tumor volume in patients with lung cancer. Therefore, our study aimed to evaluate the relationship between CTC number and primary tumor volume in patients with lung adenocarcinoma. Methods: We collected blood samples from 21 patients with treatment-naive lung adenocarcinoma and 73 healthy individuals. To count CTCs, we used a CTC enrichment method based on fluid-assisted separation technology. We compared CTC numbers between lung adenocarcinoma patients and healthy individuals using propensity score matching, and performed linear regression analysis to analyze the relationship between CTC number and primary tumor volume in lung adenocarcinoma patients. Results: CTC positivity was significantly more common in lung adenocarcinoma patients than in healthy individuals (p<0.001). The median primary tumor volume in CTC-negative and CTC-positive patients was 10.0 ㎤ and 64.8 ㎤, respectively. Multiple linear regression analysis showed that the number of CTCs correlated with primary tumor volume in lung adenocarcinoma patients (β=0.903, p=0.002). Further subgroup analysis showed a correlation between CTC number and primary tumor volume in patients with distant (p=0.024) and extra-thoracic (p=0.033) metastasis (not in patients with distant metastasis). Conclusion: Our study showed that CTC numbers may be associated with primary tumor volume in lung adenocarcinomas patients, especially in those with distant metastasis.

• Tuberculosis and Respiratory Diseases
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• v.74 no.3
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• pp.124-128
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• 2013

Pleural effusion is a rare complication in non-tuberculous mycobacterial infection. We report a case of Mycobacterium intracellulare pleuritis with idiopathic pulmonary fibrosis in a 69-year-old man presenting with dyspnea. Pleural effusion revealed lymphocyte dominant exudate. M. intracellulare was identified using a polymerase chain reaction-restriction fragment length polymorphism method and liquid cultures of pleural effusion and pleural biopsy. After combination therapy for M. intracellulare pulmonary disease, the patient was clinically well at a 1-month follow-up.

• The Korean journal of helicobacter and upper gastrointestinal research
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• v.18 no.3
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• pp.157-161
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• 2018

Liquid biopsy, the analysis of circulating biomarkers from peripheral blood, such as circulating tumor cells (CTCs) and circulating tumor DNA, and exosomes, offers a less invasive, new source of cancer-derived materials that may reflect the status of the disease better and thereby contribute to personalized treatment. Recent advances in microfluidics and molecular analysis technologies have resulted in greatly improved CTC enumeration and detection. In this article, we review commercially available technologies used to isolate CTCs from peripheral blood, including immunoaffinity and label-free, physical property-based isolation methods. Although enormous technological progress has been made, especially within the last decade, only a few CTC detection methods have been approved for routine clinical use. Here, we provide an overview of the current CTC isolation methods and examples of their potential application for early diagnosis, prognosis, treatment monitoring, and prediction of resistance to cancer therapy. Furthermore, the challenges that remain to be addressed before such tools are implemented for routine use in clinical settings are discussed.