Gastric cancer - also known as stomach cancer - it is one of the most common cancers worldwide, especially in Asia. Both men and women can be affected.
In Singapore, gastric cancer is the 4th and 6th most common cancer among men and women respectively.
The stomach lies between the oesophagus (gullet) and small intestine. It serves as a reservoir for the food we eat, and controls its passage to the small intestine where most of the food is digested.
The cause of this cancer is unknown, but there are several well-known risk factors, includng:
- A diet high in salt
- Lack of vitamin C
- Family history of stomach cancer
- Infection by Helicobactor pylori
What are the warning signs?
As the stomach is located in the upper central part of the abdomen (epigastrium), the most common symptom for gastric cancer is discomfort or pain in the upper abdomen (so-called dyspepsia). The pain experienced can be mild or severe, and may be linked to food intake.
However, not every instance of abdominal pain indicates gastric cancer. In fact, it is very difficult to differentiate discomfort caused by gastric cancer from that caused by other common diseases such as gastritis or peptic ulcers.
The other symptoms of gastric cancer include a loss of appetite, passing black stools, vomiting and weight loss. Passing black stools is a sign of bleeding from the cancer.
In the early stage of gastric cancer, there is no specific physical sign. Occasionally, there may be a lump that can be felt over the upper abdomen. The patient's face may look pale due to anemia caused by blood loss from the tumour.
In the advanced stage of gastric cancer, the patient may appear jaundiced. The abdomen may also be distended.
At this stage, the cancer can also spread to other organs, such as the liver and the rest of the abdomen.
How is gastric cancer detected?
The most common test employed to detect gastric cancer is Gastroscopy.
This is an outpatient test which takes about 10 minutes to perform.
It uses a Gastroscope - a thin, flexible tube with an attached camera - to allow the doctor to check the gastrointestinal tract.
A sedative is usually administered prior to gastroscopy, so that the patient feels comfortable during the test.
If there is any abnormal area, the doctor can perform a biopsy.
Gastric cancer can be cured if it is detected early.
If the tumour has not spread to other organs, it is usually treated with surgery. Part or the whole of the stomach will be removed, depending on the tumour size and location.
You may be surprised to know that the stomach is not a vital organ in the human body. Even if a person's stomach is removed, he only needs to adjust his dietary habits in order to enjoy a long life.
Many new methods of removing gastric cancer have recently available. However, these are effective only in cases where the tumour is small. One such method is laparoscopic surgery. It is a 'key-hole' type of surgery and requires much smaller skin incisions compared to traditional 'open' surgery. Hence, the patient experiences less pain and can recover from the procedure faster.
Another method to remove the tumour is endoscopic mucosal resection (EMR). This involves removing the tumour via gastroscopy (see graphic above). This effectively means that the patient does not require any surgery at all. EMR is only suitable for patients whose gastric cancer is still at a very early stage of gastric cancer.
Chemotherapy and, occasionally, radiotherapy are required if the tumour is in the advanced stage. It may also be used before or after surgery.
What to expect from surgery
I am going for surgery. What can I expect?
Surgery is the main treatment for gastric cancer and is done under general anesthesia.
Prior to surgery, X-rays or scans will be done to measure the stage of tumour. Other tests will also be performed to assess the patient's health condition.
During surgery, which normally lasts for 3-4 hours, the tumour and any surrounding lymphatics will be removed at the same time. The intestine will be reconnected with the remaining stomach or oesophagus.
Patients usually need to be hospitalised for about 7-10 days to recover from surgery. After about three days, they will be put on a liquid diet. They may progress to a full diet after about seven days.
After discharge, patients will be given dietary advice. They may also need to take small but frequent meals initially.
How can gastric cancer be prevented?
Developing a healthy lifestyle is the main way to prevent gastric cancer.
This should include consuming fresh fruits and vegetables, which are good for the stomach. Eating preserved food or adopting a diet with a high content of salt and nitrates (nitrosamines) is discouraged, as is smoking and drinking large amounts of alcohol.
Gastric cancer is a curable disease if it is detected early. If you have a recent onset of dyspepsia or 'gastric pain' and it does not go away after a week or two, you should see your doctor.
Gastroscopy is the most useful test to detect gastric cancer. It is a quick outpatient procedure with minimal discomfort.
If a tumour is diagnosed, it can be removed by open surgery, laparoscopic surgery or endoscopic surgery. Chemotherapy and/or radiotherapy is required if the tumour is at more advanced stage.
Associate Professor Jimmy So is a Senior Consultant and Director of Upper Gastrointestinal Surgery Service at National University Hospital.
This article was contributed by National University Hospital.