Sensitivity and Specificity of NGS in Detecting bMSI in Patients With Gastric, Duodenal and Small Intestinal Cancer

Study Overview
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Brief Summary
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To study the sensitivity and specificity of NGS in detecting Microsatellite State in blood and to evaluate its potential application in gastrointestinal cancer.

Detailed Description
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NGS can not only detect tissue samples, but also blood samples. For some inoperable cancer patients, the acquisition of tissue samples is difficult and traumatic. It is of great significance for the diagnosis and treatment of these patients to determine MSI status by blood testing. In addition, the heterogeneity of malignant tumors is usually strong, blood testing can overcome the heterogeneity of tissue, and can dynamically monitor the patient's condition. 50 patients with gastric cancer, duodenal cancer and small intestinal cancer will be enrolled in the study. Among them, 30 patients with MSI-H and 20 patients with MSS confirmed by IHC/PCR.The investigators will use 520 gene panel for NGS sequencing of tissue and blood samples from selected patients to study the sensitivity and specificity of NGS in detecting Microsatellite State in blood.

Official Title
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Sensitivity and Specificity of NGS in Detecting bMSI in Patients With Gastric, Duodenal and Small Intestinal Cancer

Conditions
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Gastrointestinal Cancer

Intervention / Treatment
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* Diagnostic Test: Next generation sequencing


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age (>18 years old). Histologically diagnosed as gastric cancer, duodenal cancer or small intestinal cancer (stage III, stage IV). The status of dMMR/pMMR was confirmed by IHC/PCR. with tissue and blood samples (including ctDNA and white blood cells) that meet the requirements. Agree to provide demographic, medical history, pathological diagnosis, imaging diagnosis, TNM staging, ECOG score and other information. Exclusion Criteria: Suffering from other malignant tumors at the same time. Others that the investigator consider that is inappropriate for this study.

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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Design Details

Primary Purpose: Diagnostic
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: MSI-H<br>IHC/PCR tested as dMMR/ MSI-H | Diagnostic Test: Next generation sequencing<br>* NGS can provide genetic and MSI test for patients<br>|
| Experimental: MSS<br>IHC/PCR tested as pMMR/ MSS | Diagnostic Test: Next generation sequencing<br>* NGS can provide genetic and MSI test for patients<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Sensitivity and specificity of blood MSI detected by NGS | To study the sensitivity and specificity of blood MSI detected by NGS. | 1 year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Ideal sequencing depth of MSI in blood test | To study the ideal sequencing depth of MSI in blood test. | 1 year | 
| Correlation between MSI status and TMB | To study the correlation between MSI status and TMB. | 1 year | 
| Correlation between MMR gene and other gene mutations | To study thecorrelation between MMR gene and other gene mutations. | 1 year | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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NGS bMSI Gastrointestinal