Stomach cancer.
A plain-language guide to stomach cancer: the types, the role of H. pylori and other risk factors, the symptoms worth acting on, and how it is diagnosed and treated in Australia.
What stomach cancer is.
The stomach is the muscular bag between the oesophagus and the small bowel, where food is churned and partly digested. Stomach cancer begins in its lining and can grow through the wall into nearby lymph nodes and organs.
About nine in ten stomach cancers are adenocarcinomas, starting in the gland cells of the inner lining. They are described by where they start (the cardia at the top, next to the oesophagus, or the rest of the stomach) and by how the cells look (intestinal or diffuse). Diffuse cancers tend to spread through the wall and are more often found late; a rare form thickens the whole wall, sometimes called linitis plastica.
Other cancers can start in the stomach, including gastrointestinal stromal tumours (GIST), lymphoma and neuroendocrine tumours. They behave and are treated differently from adenocarcinoma.
In 2025 an estimated 2,740 people were diagnosed in Australia. Across all stages, 40 out of 100 people diagnosed between 2017 and 2021 were alive five years later, up from 19 out of 100 in the late 1980s. New cases have fallen over the same period, from about 21 per 100,000 in 1982 to 11 per 100,000 in 2021.
What raises the risk.
Helicobacter pylori is the most important known risk factor for cancer in the lower and middle stomach. It is a bacterium that infects the stomach lining, causing long-term inflammation; it was classified as a human carcinogen in 1994. Most people who carry it never develop cancer, and it can be tested for and treated with antibiotics.
Other factors include smoking, a diet high in salt-preserved and smoked foods, low fruit and vegetable intake, excess body weight, age over 60, long-standing gastritis, pernicious anaemia, previous stomach surgery and a family history of stomach cancer.
A small minority of cases are inherited. Hereditary diffuse gastric cancer is caused by a fault in the CDH1 gene and carries a high lifetime risk of diffuse stomach cancer and lobular breast cancer. If your family has several cases of diffuse stomach cancer at young ages, ask for a genetics referral.
Australia has no national screening program for stomach cancer, so it is usually investigated when symptoms prompt a GP visit.
H. pylori is treatable. If you have persistent indigestion, a family history or a diagnosis of gastritis, ask your GP whether testing for H. pylori is appropriate.
Symptoms worth taking to a GP.
Early stomach cancer often causes no symptoms, and the symptoms it does cause are common to many harmless conditions. Persistence and combination are what matter.
Indigestion or reflux that will not settle
Ongoing burning or discomfort in the upper abdomen, especially if it is new or no longer responds to usual treatment.
Feeling full quickly
A sense that food sits in the stomach, or that you are full after only a small amount. This can reflect a tumour reducing stomach capacity.
Weight loss you did not plan
Often combined with reduced appetite or early fullness.
Pain or bloating in the upper abdomen
Persistent or recurrent discomfort, sometimes with nausea.
Difficulty swallowing
More common with cancers at the very top of the stomach, near the oesophagus.
Vomiting blood or black stools
Seek urgent care. Slow bleeding can also cause tiredness and anaemia without visible blood.
Tiredness or anaemia
A low blood count found on a routine test can be the first clue, particularly with longstanding stomach symptoms.
Indigestion is common; stomach cancer is not. The reason to see your GP is persistence, a change in pattern, or several symptoms together.
How it is diagnosed.
The diagnosis is made by looking inside the stomach and taking samples, then imaging to see how far the cancer has spread.
From referral to a treatment plan
Staging is described as stage 1 to 4 using the TNM system. Stage 1 is confined to the stomach; stages 2 and 3 involve deeper growth or nearby nodes; stage 4 means spread beyond the stomach.
What treatment looks like.
Surgery
Surgery is the only potentially curative treatment. A subtotal or total gastrectomy removes part or all of the stomach, and nearby lymph nodes are removed with it. The extent of lymph node removal (D1 or D2) is a technical decision made by your surgeon and should be discussed with you.
After a total gastrectomy, vitamin B12 injections are needed for life, and most people eat six to eight small meals or snacks a day rather than three large ones.
Chemotherapy around surgery
For cancers that have grown into the muscle or reached lymph nodes, chemotherapy is usually given before and after surgery. A standard approach in Australia for fit patients is the FLOT regimen (four cycles before surgery, four after), which improved survival compared with older regimens in a large trial.
If surgery happens first, chemotherapy or chemoradiotherapy afterwards may be recommended. The choice depends on the stage, the margins and your recovery.
Advanced cancer
When the cancer has spread, treatment aims to control it and maintain quality of life. Chemotherapy is the backbone. If the tumour is HER2 positive, a targeted drug is added; immunotherapy is used in selected cases based on MSI and PD-L1 status.
Surgery or stenting may still be used to relieve bleeding, obstruction or difficulty eating. Palliative care works alongside treatment on symptoms and support for family. Advance care planning, which records what matters to you and who can speak for you, can start at any stage.
Nutrition and recovery
Dietitian support is part of treatment, not an optional extra. Eating changes after gastrectomy, and some people need enzyme supplements or temporary feeding support. Ask for a dietitian before surgery.
Clinical trials
Trials in gastric cancer test new drug combinations and better ways to select treatment. Ask your oncologist whether any trial is suitable for you.
Ask about your stage and your options. Surgery, chemotherapy and supportive care are decided together. Our education guide explains the tests and terms.
The research we fund.
HOPE Fund projects look at recovery and decision-making around major foregut surgery, including stomach cancer.
Muscle, weight and treatment
A study measuring body composition before, during and after treatment for stomach and oesophageal cancer. Weight and muscle loss affect how people tolerate surgery and chemotherapy, and measuring them properly changes care.
HIIT Cancer
A randomised trial of high-intensity interval training started immediately after major foregut surgery, testing whether early structured exercise improves recovery.
Better decisions in surgery
Work using AI to support surgical decisions and make care more consistent for upper GI patients.
A family who lived it.
Joanne was diagnosed shortly before her sixtieth birthday and had a total gastrectomy two days before it. She speaks about the operation, the changes to eating, and the strength she found in research and community.
Her story is one person's experience, not a prediction. It is here because hearing how someone else moved through treatment makes the path less abstract.
Questions people actually ask.
Does H. pylori cause stomach cancer?
It is the most important known risk factor for cancer in the lower and middle stomach, and it is classified as a human carcinogen. Most people who carry it never develop cancer, and testing and treatment with antibiotics is straightforward when indicated.
Is stomach cancer hereditary?
Most cases are not. A small proportion are linked to inherited conditions, particularly hereditary diffuse gastric cancer caused by a CDH1 fault. Several cases at young ages in one family warrant a genetics referral.
Can stomach cancer be cured?
It can be cured when it is found before it has spread and can be completely removed. Treatment usually combines surgery with chemotherapy before and after. Advanced cancer is treated to control symptoms and extend good-quality time.
How much of my stomach will be removed?
That depends on where the tumour is and how far it extends. Some people have part of the stomach removed (subtotal gastrectomy) and some have all of it (total gastrectomy). Your surgeon should explain the plan and why.
Will I need vitamin injections after surgery?
After a total gastrectomy, vitamin B12 injections are needed for life because the body can no longer absorb B12 from food. After a partial gastrectomy, this is decided individually.
Is there a screening program?
No national screening program exists in Australia. Testing is prompted by symptoms, family history or a known high-risk inherited condition.
This page is general information, not medical advice. It is written for people in Australia and does not replace a conversation with your own treating team, who know your history and your scans. If you are worried about a symptom, see your GP. In an emergency, call 000.
Sources: Cancer Australia, Stomach cancer statistics (AIHW data to 2021, 2025 estimates), Cancer Council Australia, Stomach cancer, Cancer Council Australia, Optimal Care Pathway for people with oesophagogastric cancer, Cancer Research UK, Stomach cancer: types, risks and survival, National Cancer Institute, Gastric Cancer Treatment (PDQ), eviQ, Gastric and gastro-oesophageal neoadjuvant and adjuvant FLOT protocol, National Cancer Institute, Hereditary Diffuse Gastric Cancer (PDQ).
Related guides.
Oesophageal cancer
Begins in the lining of the food pipe. The two main types are adenocarcinoma (often linked to long-standing reflux) and squamous cell carcinoma. Early changes can be subtle, such as difficulty swallowing or persistent heartburn.
Read the oesophageal cancer guideGastro-oesophageal junction cancer
Begins where the oesophagus joins the stomach, an area often abbreviated as the GOJ or OG junction. It is treated by the same specialist teams as oesophageal and stomach cancers.
Read the junction cancer guideFund the work that finds it earlier.
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