Diagnosis and Treatment of Early Gastric Cancer Cure for gastric cancer can be achieved when detected early. However, identification of early gastric cancer can be very difficult. We have created this video to provide a resource on the technique on how to diagnose early gastric cancer. In addition, we have included video on the endoscopic treatment of early gastric cancer. Worldwide, gastric cancer has the highest mortality among gastrointestinal cancers and second only to lung cancer among all cancer-related deaths. Gastric cancer has a global distribution. Asian and European countries have the highest incidence of gastric cancer. They are followed by Australia, South America, and North America. It is important to identify gastric cancer early as 5-year survival rate is greater than 90% for stage 1 disease. Japan has one of the highest incidence of gastric cancer in the world. Over the last 30 years, with increased recognition of early gastric cancer, overall survival has improved. With increased immigration and ethnic diversity in the United States, it is important for physicians in the United States to be familiar with early gastric cancer. This disease can occur in Americans of all racial background. Dysmucosal cancer was found at our unit at the Palo Alto Veterans Hospital. This lesion turned out to be adenocarcinoma. In 2003, a consensus PARIS macroscopic classification for neoplastic lesions of the digestive mucosa was published. Macroscopic type 1 to 5 are considered advanced gastric cancer. In this video, we will focus on early gastric cancer. Early gastric cancer is defined as tumor that is confined to the mucosa or submucosa, irrespective of the presence of regional lymph node metastasis. Based on the PARIS classification, type 0 describes early gastric cancer that is superficial, protruding, or non-protruding. Superficial gastric cancer is then further subdivided based on its macroscopic appearance, because the risk of invasion into the submucosa varies with different subtypes. The different subtypes of superficial gastric cancer are protruded type, superficial elevated type, flat type, depressed type, and excavated type. We will now show you examples of different subtypes of superficial gastric cancer. Here is an example of a protruded type lesion, also known as type 0, 1 lesion. On pathology, there was submucosal invasion. This superficial elevated lesion, also known as type 0, 2A lesion, showed only mucosal involvement. This flat type 2B lesion involves only the mucosa on pathologic examination. Here is an example of a depressed type 2C lesion involving the submucosa. This excavated type 3 lesion invaded into the submucosa. Lesions can have multiple morphologies. This is an example of a superficial depressed lesion, shown in white, surrounding an excavated lesion, shown in yellow. Here is an example of a polypoid lesion next to a superficial depressed lesion. As the above examples illustrate, gastric lesions can be very difficult to identify. In this section, we will describe the strategies for detecting early gastric cancer, starting with preparation of the stomach. Early gastric cancers can be missed when the stomach is obscured by mucus and debris. The stomach should be irrigated with water containing simethicone to remove inherent mucus and bubble prior to gastric cancer screening. In addition to thoroughly cleaning the stomach prior to the examination, it is also important to completely insufflate the stomach during the examination. Subtle lesions can be hidden under gastric rugal folds. In this example, this red lesion, which turned out to be adenocarcinoma, would have been missed without proper insufflation. During the examination, it is often necessary to use antiperistaltic agents such as glucagon. Gastric lesions can often be missed, especially near the prepyloric and antral region. This case from the Palo Alto VA Hospital required glucagon to properly evaluate this flat and depressed antral lesion. A properly maintained endoscope is necessary for the retroflex examination of the gastric cardia and fundus. The retroflex examination is especially important given the reported increase in the incidence of gastric cancer located in the cardia. Here's an example of a well-maintained gastroendoscope examining the gastric cardia. This red patch next to the endoscope could have been missed without a properly maintained endoscope. This lesion is a superficial adenocarcinoma, type 2c. In order to ensure lesions are not missed, the stomach should be systematically examined from the prepylorus to the antrum, the lower gastric body, the middle gastric body, the upper gastric body, and finally the fundus. Each of the six sections should be examined circumferentially from the lesser curvature to the anterior wall to the greater curvature, and finally the posterior wall. At the National Cancer Center Hospital in Japan, photographs are taken of each region for documentation. Here is a video demonstrating a typical gastric cancer screening examination. As we enter the stomach, care is taken to examine the greater curvature. This step is important as endoscope trauma artifact can obscure subtle lesions. The pylorus and the duodenum should then be examined. This part of the examination is not shown. After completing the duodenal examination, the prepyloric area is examined in a circular motion, starting from the lesser curvature, followed by the anterior wall, greater curvature, and posterior wall. The circular motion of examining the stomach is repeated for the antrum, lower gastric body, middle gastric body, and upper gastric body. On retroflexion, the posterior wall of the fundus is examined first. The cardia is examined circumferentially to ensure lesions are not hidden behind the endoscope. We then re-examine the entire lesser curvature. The posterior wall of the body is examined again because it is not well visualized in the antroflexive view. A complete examination of the stomach should take less than 10 minutes if no pathology is found. Once a lesion is identified, indigo carmine is used to better characterize the lesion. Indigo carmine pools in the mucosal crevices and depressions highlighting the border and surface characteristics of the lesion. Some of the benefits of indigo carmine are that it is easy to prepare and use, it is inexpensive, and water-soluble. After opening the vial of indigo carmine, draw the dye into the syringe with a blunt-tip needle. Add 20 cc's of water and also pull in 10 cc's of air to help push the dye through the working channel of the endoscope. The dye can be injected directly through the channel or by using a spray catheter. Make sure to lavage the mucosa well prior to applying indigo carmine to allow the dye to sink into the mucosal grooves. Indigo carmine works by filling the grooves and crevices in the mucosa. This provides contrast to enhance visual evaluation of the border and topography. This video demonstrates the usefulness of indigo carmine. This is a depressed lesion in the posterior wall of the upper gastric body. The lesion has erythematous and erosive changes. The border is difficult to delineate before the application of indigo carmine. After the application of indigo carmine, the border of the lesion can clearly be identified. Familiarity with the appearance of early gastric cancers is important. We have prepared cases highlighting subtle features that will help in the identification of early gastric cancer. Characteristics such as subtle color differential, slight hemorrhage and friability, and absence of vascular network should raise suspicion of early gastric cancer. This red lesion is located on the lesser curvature of the middle gastric body. This location is usually not well visualized on entroflex view. This lesion is better appreciated on retroflex examination. This depressed adenocarcinoma located at the cardia, This depressed adenocarcinoma located at the cardia was identified by its increased redness. Indigo carmine was used to better define its border. This case illustrates the importance of using a properly maintained endoscope for the retroflex examination. This is an example showing a hyperplastic polyp on the greater curvature of the antrum. However, along the posterior wall and lesser curvature of the antrum, there is flat and irregular mucosa. The lesion appears more pale compared to the surrounding mucosa. After the application of indigo carmine, we can better identify the border of this lesion. Gastric cancer is usually friable and can bleed after minor manipulation. Initially, this lesion appears red. After indigo carmine, oozing of blood can be seen from this lesion. We usually associate oozing of blood with endoscope trauma. However, this friable and oozing lesion located on the lesser curvature side of the prepylorigum However, this friable and oozing lesion located on the lesser curvature side of the prepyloric region is a well-differentiated adenocarcinoma. This raised lesion located on the lesser curvature of the mid-gastric body lacks vascular pattern. This is a well-differentiated adenocarcinoma limited to the mucosa. This is another example of an adenocarcinoma that lacks vascular pattern. Even after the application of indigo carmine, the lateral borders are difficult to identify. A linear red lesion can be seen in the posterior wall of the lower gastric body. The posterior wall is usually difficult to examine on entroflex view using a forward-viewing endoscope. All suspicious lesions should be examined on a retroflex view. In this case, the border of this lesion actually extends more proximal to the linear red area. This case illustrates the importance of examining the greater curvature on initial entry into the stomach. This small depressed lesion could have been mistaken for a scope trauma. Closer examination is needed to fully evaluate this lesion. In this section, we will provide an overview of the endoscope. In this section, we will provide an overview of the endoscopic treatment of early gastric cancer. Endoscopic resection of early gastric cancer is currently a standard treatment in Japan. Outside of Japan, it is increasingly gaining acceptance. The major advantage of endoscopic resection is its ability to provide pathological staging without precluding future surgical therapy. In highly selected patients who have very low risk of lymph node metastasis, it offers similar efficacy to surgery and is less invasive. The most commonly used EMR techniques include the inject-and-cut, inject-lift-and-cut, EMR using CAP, EMR using ligator. This program is not intended to be a tutorial on the EMR technique, This program is not intended to be a tutorial on the EMR technique, but we feel that it is important to show a few cases to demonstrate the concept. We will demonstrate the inject-and-cut technique on this lesion at the pylorus. Due to its location, we use a side-viewing endoscope for this procedure. Indigo carmine is used to define the border of this lesion. The submucosa is injected with normal saline to separate the lesion from the muscle layer. This will minimize the risk of perforation. This lesion lifted well, suggesting that it is limited to the muscle layer. The lesion is then removed with a snare. The strip biopsy technique requires a double-channel endoscope. After the lateral margins of the cancer is marked and the submucosa injected, a forceps and snare is inserted through the two channels. The forceps is then passed through the open snare, and the lesion is grasped at the center by the forceps. The lesion is pulled until the markings are completely through the snare. The snare is then closed and the lesions resected. EMR cap method requires a specialized small plastic cap that is fitted to the tip of the standard endoscope. Different size caps are available according to the diameter of the endoscope and the size of the target lesions. Initially, the crescent-shaped snare is pre-looped into the groove of the rim of the cap. The lesion is then sucked into the cap, the snare is pushed down onto the base of the aspirated lesion, and the snare is then closed. The suction is then released and the lesion resected. In the EMR ligation technique, a band ligator is fitted at the end of a standard endoscope. The lesion is sucked into the cap and ligated. A snare is used to resect a lesion either above or below the rubber band. Conventional EMR cannot be used to resect lesions larger than 15mm in one piece. Larger lesions often require multiple piecemeal resections. Unfortunately, pathologists often have difficulty staging specimens from piecemeal resections. In addition, piecemeal resections often have high risk of tumor recurrence. Because of these limitations with conventional EMR, Japanese endoscopists have developed an endoscopic submucosal dissection technique that can resect large lesions on block. The National Cancer Center Hospital in Japan has developed the insulation-tipped dithermic knife for this special procedure. The IT knife is a needle knife fitted with a ceramic ball. The ceramic ball minimizes the risk of perforating the muscle layer. This video will demonstrate the use of endoscopic submucosal dissection technique on this red lesion. After indigo carmine is used to identify the border of this lesion, the initial step in the ESD procedure requires that the periphery of the lesion be marked using a standard needle knife. The periphery of the lesion is then injected with diluted epinephrine to raise the submucosal layer. Small incisions are then made with a standard needle knife. The IT knife is inserted into the pre-made incisions and the peripheral margin of the lesion is cut. After the lateral border of the lesion has been cut, the submucosa is then dissected with the IT knife. During the submucosal dissection, additional injection of epinephrine will be needed to identify the submucosal layer. As long as the submucosal layer is cushioned with epinephrine and the cutting plane is parallel to the gastric wall, the risk of perforation is minimized. After the lesion has been resected, it is evaluated histopathologically in 2mm slices to assess the depth of cancer invasion, degree of differentiation of the cancer, and involvement of the lymphatics or vessel. This information is used to predict the risk of lymph node metastasis and the need for further surgery. Japanese endoscopists have established a guideline for endoscopic treatment of early gastric cancer based on their data identifying lesions with minimal risk of lymph node metastasis. Long-term outcomes of patients who underwent EMR for treatment of early gastric cancer are still being studied. In conclusion, gastric cancer has the highest mortality among GI cancers and it has a worldwide distribution. Early detection and treatment offer high rate of cure. We hope this DVD has been helpful in illustrating the important features of early gastric cancer. This concludes the tutorial portion of this DVD. Please proceed to the photo library section of this DVD for additional examples of early gastric cancer. Thank you.

early gastric cancer

diagnosis

treatment

endoscopic resection

macroscopic appearance

survival rate