Methylation Analysis of Circulating Tumor DNA in Gastric Cancer

Study Overview
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Brief Summary
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The primary purpose of this trial is to describe the profile of ctDNA methylation in gastric cancer. The second purpose is to demonstrate the correlation between the plasma ctDNA methylation status and the diagnosis and prognosis of patients with early and intermediate stage gastric cancer.

Detailed Description
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Gastric cancer represents one of the common malignant tumors in China, with high incidence and mortality rates. Surgery is the conventional treatment option for early and intermediate stage gastric cancer, but the diagnosis in the early stage of gastric cancer remains a challenge to clinical practitioners. Circulating tumor DNA (ctDNA) is tumor-derived fragmented DNA with an average size of 166 bp, mixed with cell-free DNA (cfDNA) of other sources in blood circulation. ctDNA is reflecting the most up-to-date status of the tumor genome. Hence, it is considered as a novel biomarker for tumors, which can be qualitative, quantitative, and used for disease monitoring. This study is designed to evaluate the potential clinical utility of circulating tumor DNA (ctDNA) as a clinical index in the diagnosis and prognosis of gastric cancer. The primary purpose of this trial is to describe the profile of ctDNA methylation in gastric cancer. The second purpose is to demonstrate the correlation between the plasma ctDNA methylation status and the diagnosis and prognosis of patients with early and intermediate stage gastric cancer.

Official Title
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Methylation Analysis of Circulating Tumor DNA in Early Diagnosis and Prognostic Stratification in Patients With Gastric Cancer

Conditions
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Stomach Neoplasms, Circulating Tumor DNA

Intervention / Treatment
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* Diagnostic Test: Circulating Tumor DNA Methylation Sequencing
* Diagnostic Test: tissue DNA Methylation Sequencing


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: The subject is scheduled to undergo an endoscopy because of medical indications. The subject must have personally signed and dated the patient informed consent form indicating that he/she has been informed of all pertinent aspects of the study. The subject must be willing and able to comply with all study procedures. Exclusion Criteria: The subject who is unable to undergo gastroscopy. The subject with previous total or partial gastrectomy. The subject has other severe acute or chronic medical or psychiatric condition or laboratory abnormality that may interfere with the interpretation of study results and in the judgment of the investigator would make the subject unsuitable for entry into the study. The subject is unwilling or unable to provide signed informed consent. The subject who is pregnant.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| chronic gastritis<br>This group will include 80 patients with chronic gastritis and the diagnoses will be based on the British Society of Gastroenterology guidelines. | Diagnostic Test: Circulating Tumor DNA Methylation Sequencing<br>* Whole blood collection through venipuncture. DNA methylation levels by deep sequencing.<br>Diagnostic Test: tissue DNA Methylation Sequencing<br>* Isolate DNA from tissue samples from subjects. DNA methylation levels by deep sequencing.<br>|
| Moderate to severe atrophy/intestinal metaplasia/<br>This group will include 80 patients with Moderate to severe atrophy/intestinal metaplasia/ and the diagnoses will be based on British Society of Gastroenterology guidelines. | Diagnostic Test: Circulating Tumor DNA Methylation Sequencing<br>* Whole blood collection through venipuncture. DNA methylation levels by deep sequencing.<br>Diagnostic Test: tissue DNA Methylation Sequencing<br>* Isolate DNA from tissue samples from subjects. DNA methylation levels by deep sequencing.<br>|
| gastric cancer<br>This group will include 380 patients with gastric cancer and the diagnoses will be based on British Society of Gastroenterology guidelines. | Diagnostic Test: Circulating Tumor DNA Methylation Sequencing<br>* Whole blood collection through venipuncture. DNA methylation levels by deep sequencing.<br>Diagnostic Test: tissue DNA Methylation Sequencing<br>* Isolate DNA from tissue samples from subjects. DNA methylation levels by deep sequencing.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Analysis ctDNA methylation status and its Correlation to early diagnosis and prognostic evaluation of gastric cancer. | We will develop the linear model and a threshold value differentiating gastric cancer from control based on the 100 patient training set. | 1-2 years |