Effect of Obesity on Surgical Outcomes and Survival for Gastric Cancer

Study Overview
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Brief Summary
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As the number of obesity continues to increase, surgical oncologist pay more attention to the effect of obesity on surgical outcomes and survival of digestive systemin cancers. Body mass index(BMI) is one of the most widely used measurements of obesity. Abdominal fat area (AFA) calculated by computed tomography is popular because of its validity of fat distribution. There is still no consensus which of BMI and AFA could be the more effective measurement and more accurate to evaluate effect of obesity on surgical outcomes and survival. Gastric cancer is one of the most common digestive system cancers, and gastrectomy is the primary therapeutic options.It is important to compare the different measurements(BMI or AFA) to assess obesity and effect on surgical outcome and survival for gastric cancer patients.

Detailed Description
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Standard operation procedure（SOP） Preoperative evaluation Patients satisfied with inclusion/exclusion criteria will be informed to join in the clinical study and signature the inform consent. Procedures: The surgical treatments is adopted total or subtotal gastrectomy according to the Japanese Gastric Cancer treatments guidelines, 2010, Version 3. Postoperative recovery: Postoperative recovery period need to collect those relevant parameters of all the patients. All the relevant parameters had definitely definition in the Case Report Form of this study which included the preoperative, intraoperative and postoperative clinicopathologic characteristics. Follow-up: Follow-up will last to 5-year of the postoperative period. The postoperative complications is graded by the clavian-dildo classification. The postoperative complications and quality of life (change of AFA,performance status, recurrence and overall survival)are the focus of this study.

Official Title
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Effect of Obesity on Surgical Outcomes and Survival for Gastric Cancer Patients: a Single Center Prospective Cohort Study

Conditions
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Obesity, Gastric Cancer

Intervention / Treatment
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* Device: AFA group (successive patients)
* Other: BMI group (successive patients)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Preoperative endoscopy and biopsy confirmed gastric adenocarcinoma, and predictively feasible of conventional open total gastrectomy or subtotal gastrectomy; Predictively resectable diseases, of preoperative staging Japanese Gastric Cancer Association 14th Edition clinical T1N0M0-T4aN+M0; Age：≤75 years, or ≥18 years; Without serious disease and malignance disease; Without histories of abdominal surgery; World Health Organization performance score ≤2, American Society of Anesthesiologists score ≤3; No limit to sexual and race; Informed consent required; Obesity is defined as BMI≧30kg/m2 or preoperative AFA≧100cm2/cm. Exclusion Criteria: Patients with other severe complications cannot tolerate surgery: such as severe heart and lung diseases, heart function below clinical stage 2, uncontrollable hypertension, pulmonary infection, moderate to severe chronic obstructive pulmonary disease, chronic bronchitis, severe diabetes and / or renal insufficiency, severe hepatitis and / or function below the rank of CHILD B grade, and severe malnutrition, etc; Patients treated with neoadjuvant chemotherapy or radiation therapy which might affect the efficacy observation; Severity mental diseases; Primary lesion cannot be resected in the pattern of transabdominal gastrectomy, but for Whipple's procedure, or with a transthoracic approach surgery; After signature the Clinical trial agreement, patients and their agent will quit the trial.

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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No

Study Plan
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How is the study designed?
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Design Details

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


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: BMI group (Successive patients)<br>All successive patients meeting the including criteria and signed the informed consent will be measured BMI and the data will be recorded in the prospective database. The formula for BMI is weight in kilograms divided by height in meters squared (kg/m2). the normal range is usually considered to be 18.5 to 24.9, with less than 18.5 considered underweight, more than 25.0 considered overweight and above 30.0 obese. Investigators declare that there exists no conflicts of interest. | Other: BMI group (successive patients)<br>* The formula for BMI is weight in kilograms divided by height in meters squared (kg/m2). the normal range is usually considered to be 18.5 to 24.9, with less than 18.5 considered underweight, more than 25.0 considered overweight and above 30.0 obese.<br>|
| Experimental: AFA group(Successive patients)<br>All successive patients meeting the including criteria and signed the informed consent will be measured BMI and the data will be recorded in the prospective database. The abdominal fat area at the umbilical level was measured using a CT scanner(sango Mount Monitor Wireless Panel; Siemens , Munich, Germany) while the examinee was in a supine position and estimated using a Volume software (fat Pointer; Siemens , Munich, Germany). The imaging conditions were 120 kilovolt and 50 milliampere, using a 5-mm-thick slice.The areas covered by visceral fat software calculated from pixels with densities ranging from-190 to -30 hounsfield unit. No contrast agent is needed. Patients in the AFA group will be also measured by BMI. Investigators declare that there exists no conflicts of interest. | Device: AFA group (successive patients)<br>* The abdominal fat area at the umbilical level was measured using a CT scanner(sango Mount Monitor Wireless Panel; Siemens , Munich, Germany) while the examinee was in a supine position and estimated using a Volume software (fat Pointer; Siemens , Munich, Germany). The imaging conditions were 120 kilovolt and 50 milliampere, using a 5-mm-thick slice.The areas covered by visceral fat software calculated from pixels with densities ranging from-190 to -30 hounsfield unit . No contrast agent is needed.<br>Other: BMI group (successive patients)<br>* The formula for BMI is weight in kilograms divided by height in meters squared (kg/m2). the normal range is usually considered to be 18.5 to 24.9, with less than 18.5 considered underweight, more than 25.0 considered overweight and above 30.0 obese.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| postoperative complications | The criteria of postoperative complications in the BMI group and AFA group both adopt the definition of The clavian-dildo classification of surgical complications: five-year experience. Ann Surg. 2009;250 (2):187-96.Postoperative complications in Grade 1 were classified as minor complications, while complications in Grade 2 to 5 were classified as major complications. | 30-day of postoperative duration | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change of the postoperative BMI | The body weight(kilograms) and height(meters) change of all enrollment after 5-year postoperative duration were measured to get the change of BMI.The formula for BMI is weight in kilograms divided by height in meters squared (kg/m2). The change of BMI was compared between preoperation and 5-year postoperative duration. | 5-year of postoperative duration. | 
| Change of the postoperative AFA | AFA of all enrollment after 5-year postoperative duration were measured by CT. The AFA at the umbilical level was measured using a CT scanner (sango Mount Monitor Wireless Panel; Siemens , Munich, Germany) while the examinee was in a supine position and estimated using a Volume software (fat Pointer; Siemens , Munich, Germany). The imaging conditions were 120 kilovolt and 50 milliampere, using a 5-mm-thick slice. The areas covered by visceral fat software calculated from pixels with densities ranging from-190 to -30 hounsfield unit. The change of AFA was compared between preoperation and 5-year postoperative duration. | 5-year of postoperative duration | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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gastric cancer, gastrectomy, laparotomy, surgical outcome, survival, abdominal fat area, Body Mass Index