II BRAZILIAN CONSENSUS ON GASTRIC CANCER BY THE BRAZILIAN GASTRIC CANCER ASSOCIATION

ABSTRACT Background: Since the publication of the first Brazilian Consensus on Gastric Cancer (GC) in 2012 carried out by the Brazilian Gastric Cancer Association, new concepts on diagnosis, staging, treatment and follow-up have been incorporated. Aim: This new consensus is to promote an update to professionals working in the fight against GC and to provide guidelines for the management of patients with this condition. Methods: Fifty-nine experts answered 67 statements regarding the diagnosis, staging, treatment and prognosis of GC with five possible alternatives: 1) fully agree; 2) partially agree; 3) undecided; 4) disagree and 5) strongly disagree A consensus was adopted when at least 80% of the sum of the answers “fully agree” and “partially agree” was reached. This article presents only the responses of the participating experts. Comments on each statement, as well as a literature review, will be presented in future publications. Results: Of the 67 statements, there was consensus in 50 (74%). In 10 declarations, there was 100% agreement. Conclusion: The gastric cancer treatment has evolved considerably in recent years. This consensus gathers consolidated principles in the last decades, new knowledge acquired recently, as well as promising perspectives on the management of this disease.

was achieved when the sum of "fully agree" and "partially agree" reached at least 80%.This article presents only the responses of the participating experts.Comments on each statement, as well as a literature review, will be presented in future publications.

RESULTS
Of the 67 statements presented, a consensus was reached in 50 (74%).In 10 statements, there was 100% agreement.

Statement 1
The main method of gastric cancer diagnosis is through an upper gastrointestinal endoscopy with biopsy.The endoscopic examination report must contain precise information regarding location (s) of the lesion (s), approximate size, extent, infiltration, distance from the esophageal-gastric transition and the pylorus, detailing the places where the biopsies were performed.

Statement 3
Ultrasound upper endoscopy is not indicated when there are clear endoscopic signs that the cancer is invasive.It should be used when there is any doubt about the early aspect of GC.It allows to evaluate the degree of tumor invasion in the gastric wall and the presence of suspicious lymph nodes for metastases.

Statement 4
The main staging method is computed tomography of the chest, abdomen and pelvis.

INTRODUCTION
The incidence of gastric cancer (GC) has decreased around the world.Once the second most common type of cancer, currently CG is the fifth, after lung, breast, prostate and colorectal 6,10,15 .Its incidence has dropped in the last 50 years due to the improvement in basic sanitation conditions, the use of refrigerators and consumption improvement of fresh fruits and vegetables and less salt intake, which was then widely used to preserve food.Other factors that contributed to this decline were the eradication of Helicobacter pylori and the screening intensification in several countries 14 .
Despite that, the mortality rate remains high.In 2018, CG recovered the second place in cancer deaths around the world, surpassing liver cancer again and placing only after lung cancer 6 .In Brazil, it is the third most common type among men and the fifth among women 1 .According to the Instituto Nacional do Câncer (INCA) data, it is estimated that in the 2018/2019 biennium 21,290 new cases were diagnosed (13,540 in men and 7,750 in women) and about 15,000 deaths in 2017 related to it 11 .
Adenocarcinoma is the most common histological type, accountable for about 90-95% of cases.Other less common malignant neoplasms of the stomach such as lymphoma (4%), neuroendocrine tumor (3%) and gastrointestinal stromal tumor (GIST) will not be addressed in this consensus 5,9 .
Due to the continental dimension of Brazil, the incidence, management and prognosis varies widely according to the different regions of the country.In 2013, the first Brazilian Consensus on Gastric Cancer was published by the Brazilian Gastric Cancer Association (BGCA).This consensus aimed to unify and standardize the diagnosis and management of this condition 21 .Undoubtedly, the publication of this guideline made it possible to spread knowledge among medical professionals and, consequently, improve care and increase survival of these patients.
However, since the publication of the first Consensus, many aspects related to CG have changed 16,17 .It lists: new TNM staging classification was implemented by the American Joint Committee on Cancer and Union for International Cancer Control (AJCC/UICC) 18 ; the agreement between the West and the East on the pivotal role of D2 lymphadenectomy as a standard surgical treatment; the increasing role of multimodal therapy (neoadjuvant, perioperative and adjuvant chemotherapy/radiotherapy); the replacement of the systematic removal of the lymph node stations by the minimum number of 15 lymph nodes in the D2 lymphadenectomy; the indication for multivisceral resection (splenectomy); the endoscopic treatment in early GC and the role of minimally invasive surgery (laparoscopic or robotic) as an alternative surgical approach.
Thus, in view of the evidence gathered in recent years, it is opportune to update the Brazilian guidelines on CG through a new consensus.It is important to note that the guidelines hereby presented are not arbitrary and, therefore, it is up to each medical assistant/multidisciplinary team to adopt the best conduct according to local reality and the resource availability, as long as they are indeed beneficial to the patient.

METHODS
The Brazilian Gastric Cancer Association celebrated 20 years of its foundation in 1999.To solemnize this date, a commemorative day was held in Porto Alegre (RS) on August 16, when there was the opportunity to debate and present the results of this new Consensus.Three months before this event, a group of ABCG experts created 67 GC statements on diagnosis, staging, treatment and prognosis with five possible alternatives: 1) fully agree; 2) partially agree; 3) undecided; 4) disagree and 5) strongly disagree.These statements were sent to 59 specialists in GC treatment from all regions of Brazil (surgeons, oncologists, endoscopists, pathologists, etc.), embracing more than 20 universities institutions.The participants were able to mark only one answer.A consensus

Declaration 10
Currently, the staging that must be adopted is the UICC/ AJCC TNM 8 th edition.

Statement 12
Patients who had weight lost greater than 10% of their usual weight in the past six months should receive some form of nutritional therapy before starting any treatment.

Statement 13
Endoscopic resection is indicated in well-differentiated adenocarcinoma tumors, restricted to the mucosa (T1a), less than 2 cm in its longest axis and not ulcerated.

Statement 14
Early lesions with invasion of the submucosal layer, ulcerated, diffuse type and larger than 2 cm are exception criteria for endoscopic resection and should be adopted only in patients at high surgical risk.

Statement 16
For tumors that do not meet endoscopic resection indication (T1b), surgery is indicated.In these cases, the recommended lymph node dissection is the removal of the perigastric lymph nodes (D1) in well-differentiated tumors smaller than 1.5 cm and associated with the removal of some lymph nodes in the N2 chain (D1 +) for undifferentiated tumors smaller than 1.5 cm.

Statament 20
It is recommended at the end of each operation that a member of the surgical team send the surgical specimen for the pathological analysis with all the separate and identified lymph node chains.

Statement 22
Subtotal gastrectomy should be performed on distal tumors or in cases where the proximal margin is at least 5 cm between the tumor and the esophagogastric transition.

Statement 24
In tumors invading the distal esophagus, the resection margin must be confirmed by frozen biopsy.

Statement 26
Splenectomy should be performed only in advanced tumors from the greater curvature of the proximal stomach, when there is invasion of the spleen or if there is evident lymph node involvement of the splenic hilum.

Statement 27
Patients with unresectable or marginally resectable lesions may be candidates for conversion therapy, which consists of chemotherapy followed by surgery to achieve R0 resection.

Statement 31
The combined resection of adjacent or multivisceral organs can be performed, as long as the patient is in good clinical condition and, preferably, R0 resection is achieved.

Statement 48
The duodenal stump should preferably be closed using mechanical suture.

Statement 49
There is no clear scientific evidence that reinforcement of the duodenal stump stapling line reduces the incidence of fistulas.Statement 52 After gastric resection, oral feeding should be started as soon as the patient has conditions and the intestinal transit is restored.

Statement 63
Patients undergoing radical surgery or after adjuvant therapy should not be followed due to the high cost and because there is no evidence that the follow-up improves survival.

Statement 64
Patients submitted to radical surgery can be followed through abdominal ultrasound, due to its accessibility and low cost.

Statement 65
In the postoperative period of patients submitted to radical surgery, the upper endoscopy is indicated when there is clinical suspicion of recurrence and digestive symptoms.

Statement 66
The long-term follow-up should be offered to patients undergoing radical surgery or after the end of adjuvant therapy for nutritional and psychological control and support, early detection of recurrence, treatment of complications and data collection.

DISCUSSION
The word consensus originates from the Latin (consensus) and, by definition, means the agreement or uniformity of opinions, thoughts, feelings and beliefs of the majority or all of the members of a collective.Consensus are quite common in medicine.They are usually performed by experts in certain areas and consist of creating diagnostic and treatments guidelines for certain diseases 7 .
Several international societies have published their respective consensus and guidelines 2,3,4,8,12,13,19,20,22 .In fact, it is paramount that each country has its own consensus.Although GC has similar characteristics between different races, there are peculiarities between different countries that must be addressed according to local conditions.These include the incidence of the disease, sanitary conditions, eating habits, cultural aspects, accessibility to diagnostic methods and treatment, among others.These differences can be seen in our country.Due to its enormous size, there is a huge difference between the aspects mentioned between the regions of Brazil.Therefore, it is essential that each location seeks to adapt the information contained in this consensus with its own reality, always seeking early diagnosis and the most effective treatment possible.
Unlike the I Consensus published in 2013 21 , in which the participants had the option to answer only yes or no to the questions, the authors of this consensus chose to provide more options for answers.This is because GC is a complex disease, with multiple factors that may influence its management.In short, often more than one path considered to be correct can be followed.In addition, this will allow, in future publications, each statement to be commented on based on evidence from the latest medical literature worldwide.
In case of high suspicion of gastric cancer and repeatedly negative biopsies collected by upper gastrointestinal endoscopy (including macrobiopsies), the diagnosis can be made through endoscopic resection or surgery.
Positron emission tomography (PET-CT) and nuclear magnetic resonance (MRI) should be used only in selected cases.
Staging laparoscopy should be performed in cases where there is uncertainty in computed tomography regarding the presence of peritoneal carcinomatosis or when multidisciplinary treatment is planned.Peritoneal washing with oncotic cytology should be performed in all cases during staging laparoscopy and/or surgery.It may be omitted if there is frank peritoneal carcinomatosis.Analysis of serum tumor markers (CA19.9, CEA, CA 72.4) should be performed in all cases of gastric cancer.
ABCD Arq Bras Cir Dig 2020;33(2):e1514 Endoscopic submucosal dissection (ESD) is recommended as the treatment of choice for most superficial gastric tumors.
Statement 23In diffuse tumors, a proximal margin of at least 8 cm is recommended.
ABCD Arq Bras Cir Dig 2020;33(2):e1514 The use of the robotic platform has the same indications and results as laparoscopy.
ABCD Arq Bras Cir Dig 2020;33(2):e1514 Perioperative chemotherapy (before and after surgery) is indicated for stage ≥IB resectable tumors of the distal third.Adjuvant radiotherapy is recommended in cases with an indication for adjuvant chemotherapy and who did not have an adequate lymph node dissection during surgery.
The attempt of surgical resection in patients with single local recurrence and low surgical risk can be considered in selected cases.