Diagnostic tests for stomach cancer are typically done if the symptoms of stomach cancer are present or if a doctor suspects stomach cancer after discussing it with a patient and completing a physical examination . As of now, no widespread screening methods or established programs for primary prevention or early detection exist in Canada .
Medical and physical examinations
In a physical examination, the doctor feels the abdomen for fluid, swelling or other changes. They will also check for swollen lymph nodes. The doctor will then examine the medical history of a person and their family to help make a diagnosis.
In taking a medical history, the doctors will ask questions about :
A personal history of:
- Helicobacter pylori (H. pylori) infection
- Stomach surgery
- Pernicious anemia
- Gastritis: chronic inflammation of the stomach
- Working in the rubber industry
A family history of:
- Stomach cancer
- Hereditary diffuse gastric cancer
- Rare genetic conditions
- Other risk factors that may increase the risk of developing stomach cancer (i.e. obesity, diet, smoking, H. pylori infection)
- Presence of other cancers
An endoscopy is an examination of the upper gastrointestinal tract, including the esophagus, stomach and upper part of the small intestine. An endoscope, a thin lighted tube, is inserted through the throat and esophagus into the stomach to look into the patient’s stomach .
During the endoscopy, doctors can perform a procedure called a biopsy by removing small samples of tissue from any areas that look abnormal. The tissue is then examined under a microscope to find out if there are any cancer cells .
Other procedures used to diagnosis stomach cancer are ultrasounds, computed tomography (CT) scans, blood chemistry tests, laparoscopy, helicobacter pylori testing, or HER2 (human epidermal growth factor receptor 2) status testing .
To find out more about different types of stomach cancer testing please visit the Canadian Cancer Society.
If a definite diagnosis of stomach cancer has been made, the next step is to determine the stage and grade of the cancer. The cancer grade describes how abnormal the cancer cells look and behave and the cancer stage describes the tumour size and describes whether it has spread beyond the place of origin .
After stage 0 (cancer that has not grown beyond the inner layer of cells that line the stomach), stages are labeled using Roman numerals I through IV (1-4). The lower the number, the less the cancer has spread while a higher number means a more advanced cancer .
Pathologic and clinical staging
The stage of the stomach cancer can be based either on the results of physical examinations and tests or those results plus that of the surgery. Solely using the physical exams and tests is called clinical staging, while using both those and the surgery is called pathologic staging. Pathologic staging is more likely to be accurate because it allows the doctor to see the extent and reach of the cancer .
The pathologist will report on what was found in the tissue sample from your biopsy. It will include whether cancer cells were found, and what type. The pathology report will also include the following (via Roswell Park Cancer Institute):
- Tumour grade: How different the cancer cells appear from normal cells
- Tumour depth: How far the tumour has grown into the colon wall
- Tumour extension: How far the tumour has grown into nearby tissues
- Lymph node evaluation: How many lymph nodes were tested and how many have cancer cells (positive)?
- Distant metastases: Have cancer cells been found in distant body areas such as the liver or lungs?
- Margin status: Are the areas surrounding the tumour site free of cancer cells?
- Tumour deposits: Are there cancer cells where the lymph drains from the tumour?
- Lymphovascular invasion: Have cancer cells invaded the lymph or blood vessels?
- Perineural invasion: Have cancer cells invaded the nearby nerves?
- Histologic subtypes: What type of cancer cell is found?
- HER2 Neu Expression: The cancer cells are examined for this specific protein, which amplified or overexpressed, is associated with certain cancers such as stomach, breast, ovarian and uterine. If your cancer overexpresses
- HER2 Neu, targeted therapy will likely be part of your treatment plan.
Cancer treatments are becoming more and more targeted, so an accurate and comprehensive analysis by a pathologist is critical in determining the best approach.
Taken from: Roswell Park Cancer Institute