Lymph Node Staging System With a Novel Concept for Gastric Cancer: a Hybrid Type of Topographic and Numeric Ones

Study Overview
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Brief Summary
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For staging the status of lymph node metastasis in gastric cancer, typographic based staging system was applied until last decade, especially in Eastern countries. However the old typographic lymph node staging system in gastric cancer was too complicated and less accurate for predicting the prognosis. Now the numeric based lymph node staging system is used in both East and West, but it include problems: no information on the anatomical extent of the disease, preoperative lymph node staging is nearly impossible, failure to provide an appropriate treatment plan, cannot represent the extent of lymph node dissection. We designed simple and specifically representing the anatomic extent of the disease for staging the status of lymph node in gastric cancer. Thus we compared its prognostic performance of this new staging system with those of the current TNM 7th edition of AJCC/UICC.

Conditions
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Gastrectomy for Gastric Cancer

Intervention / Treatment
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* Procedure: gastrectomy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: patients were pathologically confirmed as primary gastric cancer patients underwent gastrectomy with curative intent. Exclusion Criteria: Patients underwent minimally invasive surgery patients with any distant metastases including peritoneal seeding and para-aortic LNs metastasis) when the location of lymph nodes were not divided patients underwent chemotherapy preoperatively patients had metastatic lymph nodes with unclear location

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

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| TNM 7th edition<br>staged by the current TNM 7th edition of AJCC/UICC | Procedure: gastrectomy<br>* gastrectomy with D1 + lymph node dissection for clinically early gastric cancer, and gastrectomy with D2 lymph node dissection for clinically advanced gastric cancer<br>|
| new TNM stage<br>staged by new TNM stage with new lymph node staging concept | Procedure: gastrectomy<br>* gastrectomy with D1 + lymph node dissection for clinically early gastric cancer, and gastrectomy with D2 lymph node dissection for clinically advanced gastric cancer<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Prognostic performance | The overall survival (OS) was used to evaluate the prognosis after gastrectomy. The Kaplan-Meier method and log-rank test were applied to analyze the OS. In addition, the Cox proportional hazards model was used to estimate hazard ratios (HRs). To compare the discrimination of each stage, the Kaplan-Meier curves from each stage in both staging systems was used. For comparing prognostic performance of each staging system, Harrell C-index (for measuring the predictive accuracy of survival outcome) were used. | participants will be followed for the duration of survival, an expected average of 36 months. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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gastric cancer, staging system, prognosis