Stomach cancer is rare and it usually doesn’t cause symptoms in its early stages. If symptoms do appear, they may be similar to those of other illnesses such as a stomach virus or an ulcer.
Stomach (gastric) cancer occurs when malignant (cancerous) cells develop in the lining of the stomach. Most cases of gastric cancer begin in the area of the stomach where it meets the esophagus (gastroesophageal junction). However, cancer can start anywhere in the wall of the stomach. It is also possible for cancer to spread from another part of the body to the stomach (metastasis).
In its earliest stages, gastric cancer often doesn’t cause any symptoms. This is because it grows very slowly and only causes symptoms when it reaches the larger parts of the stomach or enters into the digestive tract. This is why it can be hard to diagnose stomach cancer in its earliest stages.
If the cancer is found in its early stages, it can be more easily treated. This is why it is important to see your doctor if you have symptoms of stomach cancer, especially if they are frequent or last a long time.
Symptoms of stomach cancer include indigestion, pain or discomfort in the upper part of the stomach or feeling full earlier than usual (early satiety). The pain may be caused by bleeding from the tumour or the cancer spreading into the wall of the stomach. Sometimes the bowel may also be affected and you may be able to see or feel blood in your vomit or poo. The vomit may be bright red if there is recent blood or dark brown, like used coffee grounds, if the blood has been in the stomach for a while. The bowel may also become very soft and lose its normal shape. Occasionally, the cancer can spread to other parts of the body and cause different symptoms. If it spreads to the lungs, you might experience shortness of breath and coughing.
Some factors can increase your risk of getting stomach cancer, including age, diet and stomach disease. For example, having a stomach infection called Helicobacter pylori doubles your risk of developing the condition. You are also more likely to get the condition if you smoke or take aspirin or non-steroidal anti-inflammatory drugs (NSAIDs) regularly.
There is no screening test for stomach cancer and doctors only look for the condition when people present with symptoms. If you have a strong family history of the disease, your doctor might suggest tests to check whether you are at risk of developing it. The tests can include an endoscopy and barium swallow. These involve passing a thin tube with a camera into the mouth, down the throat and into the stomach and duodenum to view the stomach lining and oesophagus. Then, a liquid that contains barium is taken into the oesophagus and stomach to highlight any abnormal areas. The doctor can then take a small sample of tissue from the stomach lining to be examined in a laboratory to see if it is cancerous.
