Stomach Cancer: Causes, Treatment and More

Q1. What are the causes of stomach cancer?
Stomach cancer occurs when the stomach tissue grows abnormally and becomes cancerous. While the actual cause remains unknown, medical research has identified several high risk factors. For example, stomach cancer is more common in males than in females. The risk increases with age, as the incidence rate is higher in people over 50.  A history of infection with Helicobacter pylori, smoking, drinking alcohol, high-salt diet and consumption of marinated food also increase the risk of developing stomach cancer. Patients are more prone to stomach cancer in the remaining parts after partial gastrectomy.  

Q2. What are the symptoms of stomach cancer?
Symptoms of stomach cancer are usually not obvious. Common symptoms include bloating after eating, poor appetite and indigestion. Sometimes patients may eat less and lose weight. The symptoms vary with tumour location: one may have difficulty swallowing if the tumour grows near the cardia where the esophagus enters the stomach. Patients may fail to eat smoothly. If the tumour occurs near the exit of the stomach, they may vomit after eating and feel bloated with further decrease in appetite.

Stomach pain is relatively rare in patients with stomach cancer. It is more common in patients with stomach ulcers as a symptom of benign conditions. Chronic bleeding may also occur due to a tumour in the stomach, leading to anaemia in some patients. Other symptoms include pale face, exhaustion after walking a few steps, significant decrease in physical strength, and light- headedness when standing from a squatting position. Other symptoms such as facial paleness, raised heartbeat and shortness of breath should also merit attention. Some patients may have black stool. Do they need to worry whenever their stool looks black? Beware of stool that is shapeless and as dark as sesame paste, for it suggests possible bleeding in the stomach and upper gastrointestinal tract.

Q3. If stomach cancer is suspected, what should I do? What tests are performed after diagnosis?
If one experiences the abovementioned discomfort, gastroscopy is the most direct way to detect stomach cancer. During this upper GI endoscopic procedure, a camera no bigger than the little finger is inserted to examine the throat, oesophagus, stomach and duodenum. A biopsy will be performed as soon as an ulcer or lesion is detected to confirm the presence of cancer cells. This is the first step of diagnosis. What should be done when diagnosed with stomach cancer? Your doctor will order imaging tests such as CT scan or PET scan imaging to confirm tumour size as well as any invasion into, among others, the pancreas or lymph nodes, even metastasis to distant organs such as the lungs, liver, bones, abdominal cavity, etc. This information can help determine the next step of treatment. In short, the rule of thumb is to confirm the diagnosis and determine the severity, or the staging of stomach cancer. 

Q4. What are the treatments of stomach cancer?
Treatment options are determined by two factors. The first has to do with the patient’sfactor, or in other words if the patient can tolerate the treatment.. The second has to do with the tumour or cancer staging, i.e. whether it is at early, intermediate or advanced stage. Treatment options differ from stage to stage.  Some people may wonder if early stage cancer should be left untreated in patients over 90. This is wrong. Stomach cancer is curable in old patients. They should receive treatment as long as they stay clear-minded and their major organs are functioning properly.

How about the tumour factor? Based on assessments, gastroscopy is recommended if the tumour is at early stage and abnormality is found only in the stomach mucosa. Gastric lesions can be removed endoscopically by way of endoscopic submucosal dissection. When the tumour is getting larger and the lymph nodes are affected at intermediate stage, minimally invasive surgery can be considered to remove the affected area. If the tumour is huge and in close proximity to the surrounding organs, preoperative chemotherapy is first performed to shrink the tumour, followed by surgery to remove the remaining cancer cells.

Q5. Is it hopeless if the stomach cancer is at advanced stage and has spread to other organs?
In Hong Kong, 70-80% patients are found to have stage III or IV stomach cancer upon diagnosis. While most cases are diagnosed at advanced stage, should patients simply give up treatment? Does it mean all hopes are lost? Definitely not. What are the treatment options for stage III or IV stomach cancer? In stage III, cancer has spread to the lymph nodes but not other distant organs. And long-term survival rate can be maximised by preoperative chemotherapy, followed by surgery and finally postoperative adjuvant chemotherapy.

How about stage IV? The cancer may have already spread in the abdominal cavity or to other distant organs, including bones, liver, lungs, etc. Depending on the patient’s condition, new treatment options are now available in case of minor peritoneal metastasis. Together with systemic chemotherapy, intraperitoneal chemotherapy can be performed to maximise treatment outcome. These treatments are effective in shrinking the tumour for surgical removal and postoperative chemotherapy, thereby increasing the long-term survival rate. What if the stomach cancer has spread to the lungs, bones or liver? In that case, the treatment objective is to enhance the quality of life. Most advanced patients have difficulty eating, which can be improved by stomach stent placement. Painkillers are also prescribed for bone pain when necessary to maintain the quality of life.

Check out YouTube videos from HKSH Medical Group for more health information.