Stomach Cancer

What is Stomach Cancer?

Stomach cancer, or gastric cancer, is cancer of the stomach. Stomach cancer is particularly common in East Asia.

While the exact causes of stomach cancer are not clear, factors that may increase the risk of stomach cancer include:

  • A diet high in salty and smoked foods
  • A diet low in fruits and vegetables
  • Family history of stomach cancer
  • Infection with Helicobacter pylori, a bacterium that lives in the mucous lining of the stomach
  • Chronic gastritis, a long-term inflammation of the stomach
  • Pernicious anaemia, a decrease in red blood cells when the intestines cannot properly absorb vitamin B12
  • Smoking

Stomach cancer has few or no symptoms in the early stages, making early detection difficult. Symptoms, when they are present, include a loss of appetite, unexplained weight loss, chronic abdominal or gastric pain, and dyspepsia (any pain or discomfort in the upper abdomen). However, these are also symptoms of common ailments such as acid reflux or gastritis.

As such, many people, even doctors, may not immediately suspect stomach cancer. This is the main reason why stomach cancer is often discovered late. Less common symptoms of stomach cancer, which tend to present in the more advanced stages, include black stools, which is a sign of stomach bleeding.

Tests for the diagnosis of stomach cancer include:

  • Gastroscopy – This is the test most often done for stomach cancer. During this test, the doctor puts an endoscope (a long flexible tube with a camera and light) into the mouth and down into the stomach. This allows the doctor look at the interior of the stomach.
  • Biopsy – This test is performed during a gastroscopy. In a biopsy, a small sample of tissue from an abnormal-looking area of the stomach is taken, then examined under a microscope.
  • Imaging tests of the stomach – Imaging tests such as computed tomography (CT) and ultrasound scans create pictures of the inside of the body to see if the cancer has spread.

Doctors will also check for Helicobacter pylori infection. This can be done in different ways, including breath tests, blood tests, and other laboratory tests.

Stomach cancer is usually treated with one or more of the following approaches:


This can be an effective method to treat early stage stomach cancer. During surgery, the doctor may remove part or all of the stomach. In the advanced stages of stomach cancer, surgery may still be recommended to reduce complications such as blockage of the stomach or bleeding from the cancer.

Radiation Therapy

After surgery, radiation therapy, also known as radiotherapy, may be administered together with chemotherapy to destroy remnants of the cancer not removed during surgery. In patients with advanced stomach cancer, radiotherapy may be useful for relieving stomach obstruction. Radiotherapy may also be used to stop bleeding from cancers that cannot be operated on.


Chemotherapy is the use of drugs to help kill cancer cells and shrink the size of the tumour. It can be given by itself or combined with radiotherapy after surgery. Chemotherapy may also be used to reduce symptoms or prolong life in patients with advanced stomach cancer that cannot be operated upon.

Targeted Therapy

Some stomach cancers have too much of a growth-promoting protein called HER2 on the surface of the cancer cells. Tumours with increased levels of HER2 are called HER2-positive. Trastuzumab (Herceptin®) is a man-made antibody which targets the HER2 protein. Using this drug with chemotherapy can help patients suffering from advanced, HER2-positive stomach cancer live longer than just chemotherapy alone.

How to Prevent Stomach Cancer?

In many developed countries, where refrigeration has allowed a greater intake of fresh rather than salt-preserved foods, rates of stomach cancer have fallen over the years. Here are steps we can take to reduce the risk of developing stomach cancer:

  • Consume more fruits and vegetables
  • Reduce intake of salt and smoked foods
  • Stop smoking
  • Know your medical history and undergo regular gastroscopy screening if you have a history of Helicobacter pylori infection.