Patient guide
The stomach lies in the upper abdomen, just below the ribs, and plays an important role in digestion. Stomach cancer, also known as gastric cancer, develops when the cells lining the stomach wall become abnormal and grow uncontrollably. It can grow in any part of the stomach and, if not removed, can spread to surrounding lymph nodes or other organs such as the liver, lungs, bones and ovaries.
It is less common in Singapore than colorectal cancer, ranking 8th among cancers in men.1 It occurs more often in men, and most often between the ages of 50 and 70.1
The exact cause is not known, but certain risk factors increase the chance of developing it:
Early or small cancers often cause no symptoms at all, or only mild ones.1 Persistent symptoms should be assessed. Warning symptoms that need evaluation include:
If stomach cancer is suspected, your doctor will arrange a gastroscopy, where a thin flexible telescope is passed into the stomach to look for any suspicious growth. Tissue samples may be taken and examined under a microscope. Gastroscopy with biopsy is the main test, alongside CT and PET scanning.1 If cancer is confirmed, staging, usually with a CT scan, determines whether it has spread and helps decide the best treatment.
Gastroscopy shows the stomach lining directly, and a sample can be taken for biopsy from anything suspicious during the same procedure.
Treatment options include surgery, chemotherapy and sometimes radiotherapy, depending on the stage of the cancer and your general health.
Surgery involves removing the affected part of the stomach, or occasionally the whole stomach. These are called a partial or subtotal gastrectomy and a total gastrectomy, and surgery is the main treatment for stomach cancer.1 Stomach cancer is usually most treatable when it is found early, before it has spread to other parts of the body.1 Surgery is then performed with the aim of cure. Even in advanced stages, surgery may help relieve symptoms such as a blockage caused by the cancer.
Removing part or all of the stomach changes how you eat, generally meaning smaller and more frequent meals, and dietitian input is a normal part of recovery.
Depending on the stage of the cancer, one or a combination of these may be needed. Chemotherapy uses anti-cancer drugs to kill cancer cells; radiotherapy uses high-energy radiation. These may be given after surgery (adjuvant therapy) to kill any remaining cancer cells. Targeted therapy and immunotherapy are also used.1
Stomach cancer is usually most treatable when it is found early, before it has spread.1 Without treatment the cancer grows or spreads, and treatment then aims to slow it and to relieve symptoms.
H. pylori is a bacterium that colonises the stomach lining, and it is the risk factor most people have never heard of. It is a major risk factor for both peptic ulcer disease and stomach cancer.2
It is also common here. Prevalence rises with age, from 3% in children below 5 to 71% in adults over 65, with up to 31% of Singaporeans infected.2 Most people carrying it never develop cancer, so this is a risk factor rather than a diagnosis.
It can be detected by a urea breath test, during an endoscopy, or by a blood test for antibodies.2 Where it is found, treatment is a course of several medications over seven to 14 days, typically a proton pump inhibitor and antibiotics. Eradication then needs to be confirmed by a further test.2
See a doctor if indigestion or upper abdominal discomfort has persisted despite treatment, if you are becoming full after small meals, or if you have lost weight or appetite without trying.
Seek attention immediately if you vomit blood or pass black, tarry stools. Both can indicate bleeding in the upper digestive tract.
Stomach cancer ranks 8th among cancers in men in Singapore, and occurs most often between the ages of 50 and 70.1
Often not. Early-stage stomach cancer frequently causes no symptoms at all, or only mild ones.1 If indigestion, early fullness or unexplained weight loss persists, see a doctor.
Gastroscopy, with biopsy of anything suspicious taken during the same procedure. CT and PET scanning are then used for staging.1
Not necessarily. A partial or subtotal gastrectomy removes only part of the stomach, and surgery is the main treatment either way.1 Which operation applies depends on where the cancer sits and how far it has spread.
BUILD NOTE: Dr Chen’s original text is preserved throughout; the added sections and all cited figures have NOT yet been read by him. Both sources were fetched and checked on 22 September 2026, and neither page shows a review date, so the NUH prevalence figures should be read as dating from the 2016 study they cite. This page publishes no survival percentages. Dr Chen is a colorectal surgeon, so confirm with him how much gastric cancer content belongs on this site and where referrals should go.
Message Dr Chen's clinic on WhatsApp or request an appointment.
