Specialization in Gastric Cancer Surgery

Study Overview
=================
Brief Summary
-----------------
Specialization is having competent and effective knowledge on a subject, and the tendency towards specialization is increasing due to the fact that it increases the success in the follow-up and treatment process of diseases. It has been observed that specialization in cancer surgery provides significant improvement in clinical outcomes in recent years. In this study, the effect of specialization in gastric cancer surgery on clinical outcomes is being investigated.

Detailed Description
-----------------
Specialization is having sufficient and effective knowledge on a subject. Today, in the medical world, specialization is defined as having competent knowledge on a disease, and in recent years, the benefit of specialization has begun to be emphasized. Initially, it was defined as a branching and over the years, internal and surgical departments were divided into sub-areas. In surgical sciences, these fields are determined as traumatology, breast-endocrine surgery and gastrointestinal system surgery. This branching has brought a different perspective and approach to diseases and has made it possible to be more effective in the management of diseases. In recent years, a specialization approach on diseases and organ systems has developed within these branches. In surgery, surgeons specialized on many organs such as pancreatic surgery, colorectal surgery, gastric surgery, breast surgery, ovarian surgery have increased the efficiency in the management of diseases and the survival and disease-free survival rates of the patients have increased, and the postoperative morbidity and mortality rates have decreased. Gastric cancer is one of the most common malignant cancers. It is the fifth most common cause of cancer-related death worldwide. Despite advances in diagnosis and treatment methods, patients may still be diagnosed late, and patients still have a poor prognosis due to the biology of gastric cancer. Even in properly treated patients, five-year survival rates are around 20-30%. With the development of surgical techniques and disease management, clinical outcomes of the disease have improved and mortality has been reduced. In the studies, the definition of gastric surgeon was created and it was determined that the mortality decreased proportionally with the increase in the patient volume of the surgeon. In gastric cancer surgery, there are mostly studies on the number of surgeon patients and the number of hospital patients. Post-hoc analysis of hospital volume on patients included in the CRITICS study showed a 13.1% increase in survival in high-volume hospitals compared to low-volume hospitals. The number of annual resections ≥21 was determined as the definition of high-volume hospital. In addition, it was determined that there was a decrease in mortality as the number of annual cases increased in high-volume hospitals. In another study, it was seen that there was an improvement in the mortality of medium and high volume hospitals compared to low volume hospitals. The majority of studies in gastric cancer surgery have focused on hospital volume and surgeon volume. There are no data on the specialization of the surgeon other than a study based in Japan. In this study, it was aimed to evaluate the effect of specialization in gastric cancer surgery on short- and long-term clinical outcomes.

Official Title
-----------------
The Impact of Specialization on Clinical Outcomes in Gastric Cancer Surgery

Conditions
-----------------
Stomach Neoplasms, Gastric Cancer

Intervention / Treatment
-----------------
* Other: Specialization


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: cStage I/II/III gastric cancer Histologically proven gastric adenocarcinoma Underwent surgery with curative intent Exclusion Criteria: Under 18 years old Patients with non-adenocarcinoma diagnosis Emergency surgeries The need for a thoracic approach Patients with a history of non-gastric cancer

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| The non-specialized group<br>Patients who were operated by a non-specialized surgeon. Non-specialized surgeons were defined as general surgeon who does not have the characteristics of a specialized gastric cancer surgeon. The non-specialized group will be divided into two subgroups (high-volume vs low-volume) for further analysis. | |
| The specialized group<br>Patients who were operated by a specialized gastric cancer surgeon. Specialized gastric cancer surgeons were defined as surgeons who meet all of the criteria for a specialized gastric cancer surgeon. Who had undergone professional training in gastric cancer surgery in specialized gastric cancer centers (in Japan or Korea), Who identified themselves as primarily gastric surgeons during the study period Whose annual gastric cancer surgery volume is more than 21 | Other: Specialization<br>* Who had undergone professional training in gastric cancer surgery in specialized gastric cancer centers (in Japan or Korea), Who identified themselves as primarily gastric surgeons during the study period Whose annual gastric cancer surgery volume is more than 21<br>* Other names: Gastric cancer surgery;|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 30-day mortality | Death from any cause within 30 days after surgery or at any time if not discharged from hospital | 30 days after the operation (postoperative hospital stay ≤ 30 days) or operation to first discharge from hospital (postoperative hospital stay > 30 days) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 90-day mortality | Death from any cause within 90 days after surgery or at any time if not discharged from hospital | 90 days after the operation (postoperative hospital stay ≤ 90 days) or operation to first discharge from hospital (postoperative hospital stay > 90 days) | 
| Postoperative complication rate | Any complications (graded by the Clavien-Dindo classification) occurred in the postoperative period | Within 30 days after the operation | 
| Postoperative major complication rate | ≥grade-III Clavien-Dindo complications occurred in the postoperative period | Within 30 days after the operation | 
| Readmission | Readmission requiring re-hospitalization for any complications after discharge | Within 30 days after the operation | 
| 3-year overall survival | Death from any cause is defined as an event. | 3 years after surgery | 
| 3-year recurrence-free survival | Death from any cause or the recurrence of gastric cancer are an event. | 3 years after surgery | 
| Hospital stay | Duration of postoperative hospital stays | From the date of surgery until the date of hospital discharge, assessed up to 90 days after the operation | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Specialization, Postoperative Complications, Morbidity, Gastrectomy, Gastric Cancer