Monitoring Minimal Residual Disease in Gastric Cancer by Liquid Biopsy Study Description

Study Overview
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Brief Summary
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This study aims to evaluate the use of Next Generation Sequencing (NGS) to detect circulating tumor DNA in gastric cancer patients after gastrectomy

Detailed Description
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Gastric cancer is the fourth most common cancer in Vietnam with high mortality rate. Patients at early stages undergo radical gastrectomy with curative intent, but the remaining tumor cells, termed as minimal residual disease (MRD), can later cause relapse. Conventional methods to monitor MRD such as imaging and blood tests for biomarkers such as CEA are not sensitive and specific enough. ctDNA has recently emerged as a promising noninvasive marker with high accuracy to monitor MRD and detect relapse in many cancers such as breast and colorectal cancers. However, its application in gastric cancer has not been extensively evaluated. Therefore, this study aims to use advanced NGS technologies to detect ctDNA in liquid biopsy as a biomarker to monitor MRD after radical gastrectomy.

Official Title
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Monitoring Minimal Residual Disease in Gastric Cancer by Liquid Biopsy

Conditions
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Gastric Cancer, ctDNA

Intervention / Treatment
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* Diagnostic Test: ctDNA


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male or Female patients aged 18 years and older Histologically proven primary gastric adenocarcinoma before surgery Clinical stage is locally advanced cT2-4a any N and M0 In initial evaluation, patient can undergo radical gastrectomy and lymphadenectomy No preoperative therapy, including chemotherapy and radiotherapy No known cancer diagnosis within last five years Signed informed consent Exclusion Criteria: Gastrectomy cannot be achieved during operation due to metastasis Patient fails to follow-up and provide postoperative samples

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Intervention/Treatment |
| --- |
|Diagnostic Test: ctDNA|The blood samples for ctDNA and other tumor markers will be first collected within 14 days before surgery, and then be tested after gastrectomy in scheduled interval|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The sensitivity of MRD detection using ctDNA as the biomarker | The percentage of positive ctDNA detection among participants who experience disease recurrence or metastasis | 2 years after surgery | 
| The specificity of MRD detection using ctDNA as the biomarker | The percentage of positive ctDNA detection among participants who do not experience disease recurrence or metastasis | 2 years after surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Leading time between ctDNA detection and cancer recurrence detected by conventional methods | Time is measured between first positive ctDNA detection and first cancer recurrence detected by conventional methods | 2 years after surgery | 
| Mean ctDNA level (MTM/ml) of gastric cancer before operation | The mean ctDNA level in gastric cancer patients before operation | Within 14 days before operation | 
| Mutation profile of gastric cancer | Profiling of the most frequent gene mutations | Within 14 days before operation |