Professor Changlin Zhao: Screening and early diagnosis and treatment of gastric polyps, precancerous lesions and early gastric cancer

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Gastric cancer is one of the common malignant tumors in China, with high morbidity and recurrence rate, poor prognosis, low survival rate and high mortality rate
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At present, the strategy of focusing on prevention and combining prevention and treatment is strongly advocated
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Carrying out gastric cancer screening and early diagnosis and treatment is the focus of China's current urban cancer screening and early diagnosis and treatment
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Digestive endoscopy is the gold standard for early gastrointestinal cancer screening and early diagnosis.
Most early gastrointestinal cancers can be treated with radical treatment under endoscopy
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Gastrointestinal polyps, precancerous lesions and early gastric cancer were found through digestive endoscopy
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For some early gastric cancer, endoscopic resection can be used to cure the early gastric cancer, thereby saving a life, saving a family, and happy three generations
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1 Is gastric polyps a high-risk group for gastric cancer? Can precancerous lesions and early gastric cancer be screened out? The doctor will tell you clearly that gastric polyps are a high-risk group of gastric cancer.
The carcinogenesis rate of villous adenoma is about 10%~60%, especially the carcinogenesis rate of adenomatous polyps can reach 30%~58.
3%.
60% to 80% of patients with high-grade gastric intraepithelial neoplasia may develop advanced gastric cancer, which must not be taken lightly and must be given high attention
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Therefore, people at high risk of gastric cancer should have gastroscopy on a regular basis according to the doctor's recommendation
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Gastroscopy is the main screening method for gastric polyps, gastric precancerous lesions and early gastric cancer
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The development of digestive endoscopy has benefited from the advancement of modern technology, which has made the evolution of digestive endoscopy more and more clear, but it is difficult to accurately distinguish superficial mucosal lesions under conventional gastroscopy
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In recent years, the emergence of magnifying and staining digestive endoscopy has played an important role in accurately distinguishing superficial mucosal lesions and detecting early gastric cancer
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Smart medicine represented by artificial intelligence is gradually applied to the diagnosis and treatment of early gastric cancer
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Artificial intelligence is based on big data through the computer-assisted diagnosis of digestive endoscopists.
It can intelligently identify and analyze gastric tumors under endoscopy, which greatly helps endoscopists accurately distinguish superficial mucosal lesions, and further improves The accuracy of identification and early diagnosis of early gastric cancer by endoscopists has effectively reduced the missed diagnosis rate of early gastric cancer
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There is no doubt that gastroscopy screening can detect gastric polyps and gastric precancerous lesions and early gastric cancer
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Opportunistic screening (opportunistic screening), or opportunistic screening, is a new model of tumor screening proposed in recent years.
It is a clinical-based screening aimed at individuals who visit outpatient clinics or undergo health checkups.
The main purpose is to find gastric polyps, precancerous lesions and early gastric cancer through screening and to give standardized early treatment, which can effectively reduce the incidence and mortality of gastric cancer, and improve the cure rate and survival rate of gastric cancer
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Practice has proved that the compliance of opportunistic screening for gastric tumors is good, the detection rate of gastric tumors such as gastric polyps is high, the effect of early diagnosis and treatment of gastric precancerous lesions and early gastric cancer is good, and patients benefit greatly
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2.
Which gastric polyps need treatment? Stomach polyps are generally benign
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Hyperplastic polyps are non-neoplastic polyps, because they will not become cancerous, and the effect will be better through symptomatic treatment of internal medicine
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The following cases of gastric polyps require endoscopic resection or surgical treatment: 1.
The diameter of gastric polyps is less than 0.
5cm, which can be removed during gastroscopy; the diameter of gastric polyps is 0.
5cm～＜2.
0cm, which can be removed under endoscopic surgery.

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(Figures 1 and 2 can be enlarged) Figures 1 and 2 Benign gastric polyps 2.
Gastric polyps with diameter ≥ 2.
0cm, wide base, or adenomatous gastric polyps confirmed by biopsy pathology should be removed as soon as possible, and follow the doctor's instructions for regular review
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(Figure 3.
Gastric polyps with diameter ≥ 2.
0cm and wide base; Figure 4.
Adenomatous gastric polyps after endoscopic treatment) Figure 3.
Gastric polyps with diameter ≥ 2.
0 cm and wide base Figure 4.
Inside adenomatous gastric polyps 3.
After endoscopic treatment, multiple gastric polyps can be removed by stages
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(Figure 5.
Multiple gastric polyps) Figure 5.
Multiple gastric polyps 4.
Familial gastric polyps become cancerous.
It should be combined with colonoscopy and other examinations, and choose an appropriate time for surgery.
In addition to routine pathological examinations, surgery is also required after surgery.
Immunohistochemistry (IHC) to detect mismatch repair (MMR) and PCR to detect microsatellite instability (MSI), or use Next generation sequencing (NGS) for simultaneous MSI and BRAF gene detection , To provide a basis for further screening of Lynch syndrome (Lynch syndrome, LS), or LS-related tumors, these recommendations can be used as a reference for clinicians in their clinical work
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5.
For pathological examinations to confirm that gastric polyps are suspicious of cancer, or accompanied by high-grade intraepithelial neoplasia, it is recommended to perform endoscopic resection or surgical treatment depending on the specific situation
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6.
After pathological examination, it is diagnosed as adenomatous gastric polyp cancer and requires surgical treatment
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Three methods for early treatment of gastric polyps, gastric precancerous lesions and early gastric cancer 1.
Endoscopic resection Endoscopic resection is the first choice for patients with gastric polyps, gastric precancerous lesions and early gastric cancer without risk of lymph node metastasis
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1.
1 Removal of gastric polyps and precancerous lesions under endoscopy.
Most of the gastric polyps and precancerous lesions are removed under endoscopy.
Most of them are single treatment, and a few require fractional resection, with less injury and less pain; fewer complications, and perforation rate of 0% , Postoperative bleeding rate <1%; quick recovery, low cost and good effect
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① Endoscopic high-frequency electrocoagulation snare resection: It is the most widely used method at present.
Its principle is to use the thermal effect of high-frequency current to make the tissue coagulate and necrosis to achieve the goal of snare removal of polyps
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(Figure 6.
1～6.
4.
Endoscopic high-frequency electrocoagulation snare removal of gastric polyps) Figure 6.
1 Gastric polyps Figure 6.
2 Submucosal injections at multiple points around the gastric polyps to separate the mucosal layer from the muscularis propria, and the polyps are fully lifted Figure 6.
3 Endoscopic high-frequency electrocoagulation snare resection of gastric polyps Figure 6.
4 Wound after endoscopic high-frequency electrocoagulation snare resection of gastric polyps ②Endoscopic microwave burning: suitable for small diameter sessile gastric polyps, can be typed once Sexual burning
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For large diameter sessile gastric polyps, multiple treatments are required
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③Laser resection under endoscopy: It is mostly used for the treatment of gastric polyps with or without a pedicle
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④For larger gastric polyps, endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) can also be used
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1.
2 Endoscopic resection of early gastric cancer 1.
2.
1 Definition of early gastric cancer, intramucosal cancer, and submucosal cancer Early gastric cancer: Cancer cells are limited to the gastric mucosal layer or infiltrate into the submucosal layer, and are pT1N0/1M0, IA/IB stage tumors
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Intramucosal carcinoma (M): In 2015, the WHO tumor classification team classified the morphologically cancerous features of the mucosal layer but lacks the characteristics of submucosal invasion in biological behavior.
It is recommended to use "high-grade intraepithelial neoplasia (high-grade intraepithelial neoplasia).
-grade intraepithelial neoplasia, HIN)" instead of "severe dysplasia, carcinoma in situ/intramucosal carcinoma" (Shames J, et al.
Isr Med Assoc J, 2015, 17(8): 486-491.
)
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HIN includes intramucosal carcinoma (M) that is confined to the mucosal layer and infiltrates the lamina propria.
The lesion is limited to the mucosal epithelial layer as M1; the lesion infiltrates the basement membrane and the lamina propria as M2; the lesion infiltrates the mucosal muscle layer as M3
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Submucosal carcinoma (SM): SM that infiltrates into the submucosa (SM), but does not invade the muscularis propria, and infiltrates to the upper 1/3 of the submucosa (the depth of infiltration of the submucosa ≤500μm) is SM1; infiltrates into the submucosa The middle 1/3 (the depth of infiltrating submucosa <1000μm) is SM2; the 1/3 of the infiltration to the submucosa (the depth of infiltrating submucosa ≤1500μm) is SM3
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Correctly judging the depth of invasion of the lesion is an important content of preoperative evaluation, and it is the key to determine whether early gastric cancer can undergo radical endoscopic resection
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1.
2.
2 Methods for evaluating the depth of infiltration The evaluation under endoscopy should be based on white light endoscopy, mainly with the aid of dyed endoscopy and electronic dyed endoscopy, fully integrated with image-enhanced endoscopy techniques, and ultrasound endoscopy should be feasible when necessary ( Endoscopic ultrasonography, EUS), has a greater guiding significance for the depth of infiltration of the lesion and the presence or absence of regional lymph node metastasis
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Before endoscopic resection of early gastric cancer, imaging examinations such as CT and MRI enhanced scan are recommended to determine whether there is regional lymph node metastasis and distant metastasis
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1.
2.
3 Indications for endoscopic resection of early gastric cancer Absolute indications for endoscopic resection of early gastric cancer: macroscopically visible nonulcerative intramucosal carcinoma (cT1aN0, IA) less than 2 cm in size, with well-differentiated tissue types (papillary adenocarcinoma) , Well-differentiated tubular adenocarcinoma, moderately differentiated tubular adenocarcinoma)
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Expansion indications for endoscopic resection: ① non-ulcer type above 2 cm, well differentiated tissue type cT1aN0,IA; ② ulcer type below 3 cm, well differentiated tissue type cT1aN0,IA; ③ non-ulcer type below 2 cm, no vascular invasion, risk of lymph node metastasis Lower, undifferentiated cT1aN0,IA; ④The tissue type below 3cm is well differentiated cT1b-SM1N0,IA
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It is necessary to strictly grasp the indications for endoscopic resection of early gastric cancer.
EMR is mainly suitable for cT1aN0,IA of non-ulcerated and well-differentiated tissue types below 2cm
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For early gastric cancer with expanded indications, EMR cannot guarantee a high risk of complete resection of the lesion.
It is recommended that ESD is more appropriate
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1.
2.
4 The standard of radical resection under endoscopy The standard of radical resection under endoscopy: any one of the absolute indications, complete resection of the lesion, negative margins, infiltration depth of pT1a, and no vascular invasion
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Radical resection criteria for expanded indications: any of the expanded indications, complete resection of the lesion, negative margins, and no vascular infiltration
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1.
2.
5 Principles of endoscopic resection of early gastric cancer (cT1 N0) In order to ensure that the goal of radical resection under endoscopy is achieved, the principles and procedures of endoscopic resection of early gastric cancer (cT1 N0) should be followed
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(Figure 7) Figure 7.
Early gastric cancer (cT1 N0, IA) endoscopic resection principles and procedures 1.
2.
6 The exploration of remedial surgical measures after endoscopic resection usually does not meet the standard of endoscopic radical resection or expand adaptation If any condition of the standard of radical resection of the syndrome is non-radical resection, additional surgery should be recommended
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Pathologically confirmed pT1 after ESD, with vascular and nerve infiltration, additional surgery is recommended according to the patient's condition
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There are reports in the literature that the lymph node metastasis rate of pT1-SM3 early gastric cancer is 15.
8%
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Therefore, when pT1-SM3 is pathologically confirmed after ESD, or pT1b is combined with vascular infiltration, additional radical surgery is actively recommended
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The Japanese gastric cancer treatment guidelines (5th edition) stipulate that patients with cT1a N0 undergo ESD after radical evaluation, and for patients with poor evaluation, additional gastrectomy, sentinel lymph node (SLN) biopsy, and D1/D1+ regional lymph node dissection are required Surgery
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Roh et al.
used Indo cyanine Green (ICG) near-infrared imaging technology to conduct a retrospective study on patients undergoing gastrectomy after ESD
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The results showed that the ICG near-infrared imaging (ICG) group had higher sensitivity and negative predictive value for the detection of regional lymph node metastasis than the conventional group
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Conclusion: ICG-guided gastrectomy + regional lymph node dissection can replace systemic lymph node dissection (Roh CK, et al.
BrJ Surg, 2020,107(6):712-719.
)
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However, it is worth noting that in regional lymph node dissection, ICG has the problem of false negatives, and further exploration is needed
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2.
Surgical treatment 2.
1 Indications for laparoscopic surgery or laparotomy: ①Patients with progressive enlargement of polyps, or sessile or broad-based gastric polyps with a diameter of more than 2cm, pathologically proven with high-grade adenomatous gastric polyps endoscopy There is no guarantee that the whole piece will be removed
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②cT1-SM2～3 N0,IA
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③cT1 bN0,IA
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④cT1 N1,IB
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⑤For poorly differentiated pT1aN0-SM1, which has a high rate of lymph node metastasis, surgery cannot be performed under endoscopic en bloc resection
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In recent years, the emergence of new laparoscopic surgery technologies such as ultra-high-definition resolution (4K Resolution) and three-dimensional imaging (3D imaging) has further improved the accuracy of surgical operations
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At the same time, the challenge of ICG fluorescent laparoscopy to traditional laparoscopy and the evaluation of clinical effects are gradually becoming a new trend in the development of intelligent minimally invasive surgery for gastric tumors.
It is used in the precise positioning of gastric tumors, SLN biopsy, and complete regional lymph node dissection.
An increasingly important role
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The NCCN (V1 version in 2021) gastric cancer guidelines recommend that for newly diagnosed gastric cancer patients, when the ECOG score is ≤2, PCR should be performed to detect MSI or IHC to detect MMR to assess the MSI/MMR status of patients with gastric cancer
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For patients with deficiency mismatch repair (dMMR) as the result of IHC testing, MSI and BRAF gene testing can be performed simultaneously through Next generation sequencing (NGS), and the decision is made according to the status of MSI and BRAF and the patient’s wishes.
Whether it has undergone methylation analysis or germline detection of related genes to provide a basis for further screening for LS or LS-related tumors
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Four summary gastroscopy is one of the most effective means to screen for gastric tumors, and is currently the gold standard for gastric tumor screening
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Through gastroscopy screening, gastric polyps, high-grade adenomatous gastric polyps, and precancerous lesions can be detected and diagnosed early, and early treatment under standardized endoscopic resection can be performed, which can effectively reduce the incidence of gastric cancer
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For gastric polyp carcinogenesis and early gastric cancer detected early in the screening, standardized endoscopic resection and early treatment with surgical operations can improve the cure rate and survival rate of gastric cancer, prolong the survival period of patients, and reduce the recurrence rate and death of gastric cancer.
Rate
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Prevention first, screening first, one step to the "stomach", combination of prevention and treatment, early diagnosis and treatment, and head to the "stomach"! Prof.
Changlin Zhao National Class III Professor, Chief Physician, Doctor of Medicine, Master Supervisor Director of the Department of Gastrointestinal Oncology, Xinhua Hospital Affiliated to Dalian University Head of Dalian Colon and Rectal Cancer Diagnosis and Treatment Base, Chinese Anti-Cancer Association, Standing Committee of Liaoning Colorectal Cancer Professional Committee, Chinese Anti-Cancer Association Member of the Standing Committee of the Liaoning Provincial Gastric Cancer Professional Committee Member of the Standing Committee of the Liaoning Base of the Abdominal Tumor Committee of the Chinese Medical Education Association Member of the Standing Committee of the Liaoning Provincial Tumor Marker Professional Committee Member of the Eighth and Ninth Committees of the Science Society Chinese General Surgery Literature (Electronic Edition) Editorial Board Member of the Chinese Electronic Journal of Colorectal Diseases Special Expert Reviewer, National Natural Science Foundation of China Project Reviewer, National Health Commission, Science and Technology Project Reviewer, National Ministry of Education Science and Technology Project review expert, Dalian Community Health Service Research Association, Chairman of the First Dalian Community Tumor Prevention and Treatment Professional Committee