CT scan can not reliably detect all stomach cancer. CT is more commonly used for staging of known gastric cancer. Staging means to see how advanced the cancer is. CT is also used for assessing how the cancer responds to treatment.
What is the best test to diagnose stomach cancer?
Endoscopy is the best test to identify gastric cancer. Endoscopy uses a long flexible tube with camera at the tip to look inside your upper digestive tract. Endoscopy allows direct visualization of the tumor, it’s extent and allows a biopsy for diagnosis.
Risk factors for stomach cancer
Stomach cancer has a low 5 year survival rate, so early detection is essential. The cancer has been associated with helicobacter pylori infection. There are many risk factors such as reflux disease, smoking, obesity, chronic inflammation of stomach, and smoked food consumption.
Stomach tumors can sometimes be identified on a CT scan as an unexpected finding. They are however often large and obvious. Sometimes patients present with cancer which has already spread.The early curable tumors are often not seen. Even larger tumors may not be seen for a variety of reasons.
Why isn’t CT great for detecting stomach cancer?
The reason that stomach masses are not seen at times may be because the stomach is empty or collapsed on itself and therefore hides the tumor. In other cases, the stomach may be full of food and hide the mass. Food can even mimic a mass.
A partially filled stomach may cause the wall to look thick and cancerous when it is normal. The stomach also contracts and can cause a thickening which can erroneously be interpreted as a mass. CT of the stomach is not reliable for stomach masses in routine cases.
CT is best for staging stomach cancer. This means we see how far the cancer has spread in the body. This can mean spread through the stomach wall into adjacent structures, lymph nodes and distant parts of the body. We can also monitor patients who are receiving treatment for metastatic stomach cancer with chemotherapy.
What is the prognosis of stomach cancer?
Stomach cancer which is confined to the wall has the best prognosis. Stomach cancer which has spread through the stomach wall and invades adjacent structures has worse prognosis. Lymph node involvement and distant metastasis makes the prognosis the worst.
CT can identify stomach cancer but is not a reliable test. Endoscopy should be done if there is concern for cancer or to further evaluate any symptoms such as pain, reflux, weight loss, indigestion, etc. CT is best for staging cancer and for assessing response to treatment.