Cancer is something that everyone wants to avoid but often avoids. In modern society, the incidence of cancer is increasing year by year due to air and water pollution, food safety difficulties, lifestyle changes, stressful life rhythm and other reasons. Most of the cancers we find are in the middle and late stages, and patients have to suffer from both the disease and treatment (surgery and radiotherapy), which also bring heavy economic burden to families and the country. At present, the best way to deal with cancer is to completely eliminate it in the bud. Gastrointestinal endoscopy is an excellent weapon and the best friend, which helps us achieve early detection, early diagnosis and early treatment of digestive tract tumors. Endoscopic technology has flourished, and the popularity of pigmented endoscopy, narrowband endoscopy, blue laser endoscopy, magnifying endoscopy, ultrasonic endoscopy, etc. on top of high-definition endoscopy has helped us to detect more early cancers and precancerous lesions. After early detection, we envisioned whether a technique could be used to locally excise the cancer at a specific stage of growth, causing only a very small amount of trauma, to achieve the same effect as doing major surgery. Now, we have found this specific stage and the technique of local excision. Early cancer is defined as cancer confined to the intramucosa and submucosa, with or without lymph node metastasis. We can cure endoscopically only a part of them – intramucosal carcinoma without lymph node metastasis. In 1996, the National Cancer Center Hospital in Tokyo studied 1,000 patients who underwent surgical resection for early intramucosal gastric cancer and suggested that the risk of lymph node metastasis in this type of early gastric cancer was so low that radical surgery with lymph node dissection was not necessary. 2000, Gotoda et al. examined 5265 patients with early gastric cancer who had undergone gastrectomy plus lymph node dissection and found that only 2.3% of patients had local lymph node metastasis. Among these lesions, lymph node metastasis was more likely to be present in those with hypofractionation, indolent sign, lymphovascular infiltration, lesions larger than 3 cm, and superficial ulcers. Lymph node metastasis was seen in 18% of patients with cancer invading the submucosa. However, lesions less than 3 cm with submucosal infiltration less than 500 microns, histology suggestive of hyper- or intermediate differentiation, and no lymphovascular infiltration showed no lymph node metastasis. These studies provide a theoretical basis for endoscopic resection of early cancer. Endoscopic mucosal resection (EMR) and submucosal dissection (ESD) can resect early cancers of the GI tract. EMR has been performed since the 1970s and is a simple and mature technique, but for larger lesions it cannot be resected at once and needs to be performed in pieces. ESD has been performed first in Japan since the end of the last century and has become a standard procedure for early cancers in Japan and has been performed in China for more than 10 years. For early-stage cancer, can we really cut it cleanly under endoscopy without open surgery? The fear of cancer naturally makes us doubtful. In the era of EMR, as endoscopic surgeons, we also had the same doubts, because EMR is prone to residual and high risk of recurrence, while ESD eliminates such risks and is a reliable, safe and effective method. When we first started ESD, the surgeons and some patients still had doubts, but it takes a process for anything new to be accepted. Prof. Guiqi Wang from Cancer Hospital of Chinese Academy of Medical Sciences proposed that the absolute indications for ESD are lesions in the epithelial layer (m1) and lamina propria (m2). The wall of digestive tube is divided into mucosal layer, submucosal layer, intrinsic muscle layer and plasma layer in order from inside to outside, and the mucosal layer is divided into three layers: epithelial layer (m1), intrinsic layer (m2) and mucosal muscle layer (m3). All cancers start from epithelial layer glandular duct epithelial cells. Intraepithelial cancer is also called carcinoma in situ, and there is no lymph node metastasis for carcinoma in situ, while the risk of lymph node metastasis for carcinoma in the lamina propria is about 2%~4%. If the patient does not have hypofractionation, indolent sign, lymphatic duct infiltration, lesion larger than 3
cm, superficial ulcers, etc., lymph node metastasis is almost zero. In contrast, mucosal muscle layer (m3) and submucosal superficial layer (sm1) are relative indications, and the degree of differentiation, lymph node metastasis and lymphovascular infiltration need to be considered. Preoperative CT or ultrasound endoscopy must be performed before ESD to exclude lymph node metastasis. Intraoperative determination of lesion border is the first step of ESD. For gastric lesions, especially when combined with intestinal metastasis, it is difficult to determine the border.
We mark about 5 mm outside the border and make a circumferential incision outside the marker point, requiring the marker point to be on the cut specimen. Very critical is the work of the pathology department. The pathology department makes consecutive sections of the entire specimen at 2
Each section is carefully observed to find the heaviest lesion and the most deeply infiltrated area, and to determine the horizontal and vertical margins to provide us with the most accurate pathological assessment. If a lesion is resected whole, predominantly differentiated tumor, confined to the mucosa, without ulceration, without vascular infiltration, and with negative margins, it is considered a curative resection. Additional surgery or radiotherapy, as appropriate, is required for residual lesions. Gastroscopy is usually reviewed at 3 months, 6 months, and 1 year postoperatively. At the time of review, we use magnified endoscopy to look carefully for irregular openings in the glandular ducts and take biopsies at suspicious sites. The fear of cancer makes us work conscientiously, with strict screening of cases, careful marking of lesion boundaries, strict pathological evaluation, and close postoperative follow-up, doing every detail and not daring to slacken at every step. Endoscopic detection of early cancer and endoscopic resection of early cancer, endoscopy gives us an excellent choice and valuable opportunity. Prof. Li Zhaoshen once said that discovering an early cancer saves a life and a family. When we talk with each family member of early cancer, we always say one thing: congratulations, you found it in time.