Endoscopic mucosal resection for early gastric cancer

In foreign countries, especially in Japan, endoscopic mucosal resection has been used in clinical practice for more than ten years and has been widely accepted as a standard treatment for early gastric cancer. At present, the surgical radical resection rate of early gastric cancer in Japan is declining year by year, while EMR treatment is increasing. Some specialized hospitals have accounted for 40%-50% of the operation. In my country, this proportion is still relatively low, and hospitals carrying out this work are not yet popular. With the continuous improvement of clinical practice, endoscopic resection of early gastrointestinal cancer has attracted more and more doctors and patients' recognition and first choice due to its good effect, less trauma and low cost.

1. Indications for EMR: ① Type IIc with a tumor diameter of <1cm and type IIa, type I and well-differentiated adenocarcinoma with a tumor diameter of <2cm, and no macroscopic ulcer lesions; ② Patients of advanced age or with a tumor diameter of >2cm who cannot tolerate surgery or refuse surgery due to systemic conditions. Type III and scarring indicate that the submucosal layer has been invaded and are not suitable for EMR. Type IIa + IIc has a high rate of lymph node metastasis and must be combined with other comprehensive treatments after EMR.

2. Operation method Literature reports that there are four types of endoscopic resection for gastric cancer: snare resection, clamp resection, stripping biopsy and suction resection. The general operation method is: ① Endoscopic observation of the morphology and range of the lesion (pigment staining can be used); ② Use the electrocoagulation probe or the end of the snare to mark (demarcation line) 2-3mm away from the lesion; ③ Inject 10-20ml of 1:10000 adrenaline saline into the submucosal area at 4-5 points on the demarcation line to make the lesion bulge; ④ The snare electrocoagulation method is used to remove the raised lesion once or in several times; ⑤ Check the resection site, the marked points should be completely removed, and if there is any residue, a second resection should be performed. The cut specimen should be completely spread on a piece of paper and fixed in formalin solution. Pathology should be performed by continuous sectioning and the resection margin should be checked. If there is no residual lesion, it is cured. If there is residual lesion or submucosal infiltration, surgical treatment should be considered.

3. The efficacy of EMR is consistent with the above evidence. The 5-year survival rate of EMR for early gastric cancer is reported to be 80%-100%, which is related to the tumor range, preoperative estimation of the depth of invasion, the location of the tumor, and the EMR technology. Complications are rare, about 2.24%, of which bleeding accounts for 7.9%, perforation 11.3%, and mortality 0.07%. Therefore, EMR is a safe and reliable treatment method.

4. The prognosis of EMR is well known. The classic radical subtotal gastrectomy is effective in treating EGC, with 5-year and 10-year survival rates of more than 90% and 80%, respectively. EMR can obtain the same prognostic results. Ohashi et al. followed up 48 patients with intramucosal carcinoma treated with EMR for more than 5 years, and only 3 cases of tumor recurrence were found. The pathological sections of these 3 cases were reviewed again, and it was found that 2 of them were submucosal carcinomas and were transferred to surgical resection; 1 case was intramucosal carcinoma with scar formation, and EMR treatment was performed again. These 3 recurrences also survived for more than 5 years. Therefore, EMR is most suitable for intramucosal carcinoma. T8ujitani et al. conducted a retrospective study on 890 patients with EGC, comparing multiple methods and multiple indicators. The results showed that EMR has more advantages than other methods, such as less trauma, low cost and shorter hospitalization time. Moreover, the postoperative survival rate of the EMR group was the same as that of the radical subtotal gastrectomy group, and lymph node clearance did not improve the survival rate. It is suggested that patients with raised and flat cancers <2 cm, ulcerated cancers <1 cm, and well-differentiated cancer tissue are most suitable for EMR treatment, and radical subtotal gastrectomy is unnecessary. Endoscopic follow-up is required after EMR, and surgical treatment is required if there is residual cancer or recurrence.