Esophageal cancer occurs when the cells in the esophagus divide out of control.
What are the diagnostic procedures for esophageal cancer ?
Upper gastrointestinal (GI) endoscopy and biopsy
In Upper gastrointestinal endoscopy, the doctor inserts an endoscope (a thin long tube with a camera and light fitted at one end ) in the esophagus and stomach.
Endoscopy is performed after the administration of anesthesia. It is important in diagnosis, staging and devising a treatment plan, and surveillance in case of Esophageal cancer.
Bronchoscopy, if the tumor is at or above the carina. It is performed to detect cancer in areas such as trachea (windpipe) and bronchi
Chest/abdominal CT with oral and IV contrast
A CT scan uses X-rays to view images of organs inside the body. It can tell whether the cancer has metastasized or not.
PET refers to Positron emission tomography that detects cancerous cells by adding radiative glucose into your body. The cancerous cells take up more glucose as compared to normal healthy cells. The PET thus tells us where the cancerous cells are present and to what extent they have spread.
PET with CT can help detect the cancerous area in the body to obtain its images.
Complete blood count (CBC)
It is a blood test to check the cells.CBC: can tell whether you have anemia( presence of very few Red blood cells ) due to bleeding
Endoscopic ultrasound (EUS)
Endoscopic ultrasound (EUS) utilizes image-guided techniques to enhance our ability to see and understand the lesion (abnormal area). It helps create visualizations of the affected area during the examination.
Endoscopic ultrasound (EUS) in Staging of esophageal cancer: EUS is used to stage esophageal cancer by providing important information about the extent of the disease:
- T Stage: EUS helps determine how deeply the tumor has invaded the layers of the esophageal wall.
- N Stage: It assesses if the cancer has spread to nearby lymph nodes.
- M Stage: It indicates whether the cancer has metastasized to neighboring organs.
- Staging in case of endoscopy: EUS assists in identifying the location and stage of the tumor within the esophagus. The tumor stage is categorized as T1, T2, T3, T4a, or T4b based on how deep the cancer has penetrated the layers of the esophageal wall.
- T1: Tumor has penetrated the mucosa and submucosa layers.
- T2: Cancerous cells have moved past these layers and penetrated the muscularis propria.
- T3: Tumor extends beyond the muscularis propria and invades surrounding tissue.
- T4a: Invasion to nearby structures like pleura, diaphragm, and pericardium.
- T4b: Invasion of cancerous cells to structures like the aorta, heart, lungs, trachea, liver, and pancreas.
Endoscopic ultrasound (EUS) is used to view lymph nodes in the Mediastinal ( central area of the chest) and perigastric ( near the stomach ) region.
If the lymph node is suspicious of malignancy, Fine Needle Aspiration (FNA).
FNA is a process where we use a fine needle to excise a part of the lymph node followed by an examination to check for cancerous cells.
CT and FDG-PET (fluorodeoxyglucose ) can be performed before EUS to determine the location of lymph nodes. This help while performing Fine Needle Aspiration (FNA).
FNA should only be performed if it's s not disrupting any blood vessels or primary tumor.
• Endoscopic resection (ER)
ER is beneficial when performed during the early stages of cancer. It provides valuable information about the extent of the disease, such as
a. Differentiation of cancer cells (how advanced they are).
b. Presence of vascular or lymphatic invasion.
c. Depth of invasion through the esophageal wall.
ER can be considered a treatment option if:
- The cancer cells have not gone beyond the submucosa (second layer of the esophageal wall).
- Negative margins are achieved after tissue removal (no cancerous cells at the edges).
For nodules equal to or less than 2 cm, ER is preferable over EUS as it can tell us the extent of tumor growth through the esophageal wall.
• Microsatellite instability (MSI) and Mismatch Repair (MMR) Testing.
MSI stands for microsatellite instability, which is a marker on DNA. It Helps to determine the change in microsatellite ( the mutation that takes place ), thus helping in devising a treatment plan.
Mismatch repair (MMR)
It is a mechanism for DNA repair. The test is used to check if there is a mistake in the MMR mechanism in tumor cells.
•HER 2 testing
HER 2 test is done to assess whether the tumor has overexpression of HER 2 protein. It is done for metastatic esophageal cancer so that targeted therapy can be used.