The processes of diagnosing an esophageal cancer is undertaken if a patient complains of difficulties swallowing. The following tests are usually performed to evaluate the esophagus:
- A barium swallow involves the use of a contrast dye – a thick paste – that is swallowed, coating the inner lining of the esophagus. X-ray images of the esophagus are then obtained while the barium is swallowed. The test is painless and only takes a few minutes.
- Endoscopy involves the insertion of a camera attached to a long, flexible tube into the esophagus. The procedure is done under some intravenous sedation and is relatively painless. Biopsies of any masses can also be taken during the procedure. The tissue samples obtained during endoscopy are analyzed under a microscope to determine the type of malignancy.
Staging Processes of Esophageal Cancer
Once an esophageal cancer has been diagnosed, tests are done to stage the cancer. Staging determines the size and spread of tumor. It is very important to stage the malignancy because different stages require different treatments. The four classic tests used t stage an esophageal cancer include:
- Bronchoscopy: This test is similar to endoscopy, except that a long flexible tube with a camera is used to check the breathing tube. The esophagus lies just in front of the trachea and often spreads posteriorly very early on.
- Computed Tomography (CT scan): This imaging test requires the use of x-rays to determine the spread of the esophageal cancer within the chest and to other organs like the liver or stomach.
- Endoscopic Ultrasound: This is an excellent method used to detect the local spread of the cancer. When the esophageal cancer grows, it has a propensity to grow outside the layers of the esophagus and invade adjacent lymph nodes or organs. Endoscopic ultrasound can determine accurately the depth and site of penetration. Further, this technique also allows the physician to obtain biopsy samples from any suspected masses.
- Positron Emission Tomography (PET scan): PET scan is a relatively new radiological test used to stage cancers. It involves injecting a radioactive tracer molecule into the body, after which images of the tracer are obtained. This tracer, usually glucose, will go to areas of the body where there is a lot of metabolic activity (E.g. cancer). Cancer usually absorbs a lot of tracer activity and images are obtained.
Stages of Esophageal Cancer
Esophageal cancers are staged as follows:
- Stage 0: This stage indicates a cancer that is in its infancy (referred to as carcinoma in situ), when there are only a few abnormal cells present. The tumor is almost always cured at this stage if it can be completely removed.
- Stage I: When cancer cells are found only in the top layer of the esophagus, the cancer is termed Stage I. Patients have an excellent prognosis at this stage if the tumor is removed.
- Stage II: This stage involves the invasion of cancer into the deeper layers of the esophagus.
- Stage III: This stage indicates a cancer that has penetrated the entire esophagus and begun invading adjacent lymph nodes.
- Stage IV: When a cancer has spread to other organs like liver, lung, or bones, it is termed Stage IV.