The Relationship Between Microsatellite Instability and Efficacy of Fluorouracil Based Adjuvant Chemotherapy in Gastric Cancer After Operation

Study Overview
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Brief Summary
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The relationship between Microsatellite instability and efficacy of fluorouracil based adjuvant chemotherapy in gastric cancer after operation.

Detailed Description
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To explore the relationship between Microsatellite instability and efficacy of fluorouracil based adjuvant chemotherapy in gastric cancer after operation.

Official Title
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The Relationship Between Microsatellite Instability and Efficacy of Fluorouracil Based Adjuvant Chemotherapy in Gastric Cancer After Operation

Conditions
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Gastric Cancer

Intervention / Treatment
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* Other: Microsatellite instability


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Histopathology or cytopathology proven gastric cancer; Operable advanced gastric cancer patients: primary lesions can be completely excision, no distant metastasis; Postoperative patients who can tolerate 5-FU based (5-FU，S-1 or Capecitabine) adjuvant chemotherapy; Life expectancy of at least 6 months; ECOG（Eastern Cooperative Oncology Group ） score 0-1; Age: 18 80 years old; Normal hemodynamic indices before the recruitment (including blood cell count and liver/kidney function). For example: WBC（White blood cell count ）>4.0×109/L; NEU（Neutrophils）>1.5×109/L; PLT（Platelet）>100×109/L; Roughly normal cardiopulmonary function: No coronary heart disease, myocardial infarction, pulmonary heart disease, refractory hypertension; Not concomitant with other uncontrollable benign diseases before the recruitment; 9. Voluntarily signed the informed consent. Exclusion Criteria: Advanced gastric cancer patients with distant metastasis and inoperable ; Patients who cannot tolerate 5-FU based adjuvant chemotherapy; Pregnant or lactating women; Patients who have no desire to participate in the study.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 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

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| MSI-H group<br>We use the immunohistochemical expression of mismatch repair proteins (MutS protein homolog 2( MSH2),MutS protein homolog 6( MSH6) and PMS2（postmeiotic segregation increased 2 ）) to Determine the MSI status . When one antibodies or more show negative nuclear staining of the tumor cells, the MSI state can be defined as Microsatellite instability high (MSI-H). | Other: Microsatellite instability<br>* The microsatellite instability status are definite to three type:MSI-H, MSI-L,and MSS. The gastric cancer patients who received D2 resection were included in 3 groups：MSI-H group， MSI-L group，and MSS group. All patient must be accept fluorouracil(5-FU) based adjuvant chemotherapy. We will analyze the relationship between MSI status and efficacy of 5-FU based adjuvant chemotherapy by observing the survival period of patients with different MSI status.<br>|
| MSI-L group<br>We use the immunohistochemical expression of mismatch repair proteins (MLH1, MSH2, MSH6 and PMS2) to Determine the MSI status . when all the four antibodies show positive nuclear staining of the tumor cells, the MSI state can be defined as Microsatellite stable (MSI-L). | Other: Microsatellite instability<br>* The microsatellite instability status are definite to three type:MSI-H, MSI-L,and MSS. The gastric cancer patients who received D2 resection were included in 3 groups：MSI-H group， MSI-L group，and MSS group. All patient must be accept fluorouracil(5-FU) based adjuvant chemotherapy. We will analyze the relationship between MSI status and efficacy of 5-FU based adjuvant chemotherapy by observing the survival period of patients with different MSI status.<br>|
| MSS group<br>We use the immunohistochemical expression of mismatch repair proteins (MLH1, MSH2, MSH6 and PMS2) to Determine the MSI status . when all the four antibodies show positive nuclear staining of the tumor cells, the MSI state can be defined as Microsatellite stable (MSS). | Other: Microsatellite instability<br>* The microsatellite instability status are definite to three type:MSI-H, MSI-L,and MSS. The gastric cancer patients who received D2 resection were included in 3 groups：MSI-H group， MSI-L group，and MSS group. All patient must be accept fluorouracil(5-FU) based adjuvant chemotherapy. We will analyze the relationship between MSI status and efficacy of 5-FU based adjuvant chemotherapy by observing the survival period of patients with different MSI status.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Disease Free Survival | The time from the primary operation to disease recurrence or death. | 5 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Overall survival(OS) | The The time from operation to death or the last follow-up. The time from operation to death or the last follow-up. | 5 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Microsatellite Instability, Fluorouracil, Adjuvant chemotherapy, Efficacy, Operation