Only patients with early stage, no lymph node metastasis or minimal risk of metastasis should undergo endoscopic resection or nonresection. Therefore, pre-treatment staging is very important.
Your doctor will put you through a number of tests and, based on the gastroscopy and pathology, will assess whether you have early-stage cancer or precancerous lesions and whether you can receive endoscopic treatment.
What tests do I have to do?
The main tools that can help your doctor with clinical staging are imaging (including upper gastrointestinal imaging, CT, ultrasound, PET-CT, etc.) and endoscopy (gastroscopy, ultrasound gastroscopy, etc.), which can confirm your diagnosis and rule out the presence of lymph node metastases. If there are lymph node metastases, endoscopic treatment cannot be done.
Endoscopy (mainly electronic gastroscopy) is the most important in the diagnosis of early esophageal cancer.
Gastroscopy
The purpose is to confirm the diagnosis of the disease by direct observation of the mucosal surface of the esophagus and by taking mucosal tissue for pathological examination.
One of the most used endoscopic adjunct techniques in esophageal cancer screening is iodine staining, or staining endoscopy. During endoscopy, the esophageal mucosa is stained by spraying iodine solution. The doctor will determine the possibility of tumor presence based on the depth of esophageal mucosa staining, the extent of staining and the edges. Staining endoscopy is of great clinical importance in the diagnosis and treatment of early esophageal cancer.
Magnification gastroscopy and ultrasound gastroscopy
You may need additional magnification gastroscopy and ultrasound gastroscopy in order to more accurately determine the clinical stage of the tumor. Both of these tests require an experienced endoscopist.
Magnifying endoscopy (ME) optically magnifies the mucosal surface 80 to 100 times and helps determine the nature of the lesion and the potential for endoscopic treatment by looking at changes in the microstructure of the mucosal surface.
Ultrasound gastroscopy (endoscopic ultrasonography, EUS) is equipped with an ultrasound probe at the front end, allowing scanning of the esophageal wall at all levels to help determine the depth of the lesion.
Both of these tests take slightly longer to perform than regular gastroscopy. Before treatment, physicians often choose ultrasound endoscopy to determine the extent, size, and depth of infiltration of the lesion, as well as the presence of lymphatic tract or vascular metastases. This is the primary requirement for early GI tumor resection using endoscopic submucosal dissection (ESD) and endoscopic mucosal resection (EMR).
What do I need to do before a gastroscopy?
The day before the exam, you will need to abstain from smoking and alcohol.
To allow your physician to better visualize the mucosa of the digestive tract, you will need to fast for 6 hours before the exam.
For a clearer view, your doctor will also remove foam and mucus from your esophagus. The nurse will give you a small “sweet and sour” drink 30 minutes before the test, which is a medicine to get rid of the foam and mucus in your stomach.
After you drink this, you will have another glass of “gooey” liquid, which is an anesthetic for the throat.
For the exam, you will remove your dentures and glasses and lie on your left side. The nurse will ask you to open your mouth and put on a mouth pad to prevent your teeth from accidentally biting into the scope (gastroscopes are expensive).
The body and head should not be turned during the examination, as this may interfere with the examiner’s work and may cause unnecessary injury.
Co-written by:
Dr. Wang Police, Endoscopy Center, Peking University Cancer Hospital