A stomach ulcer and stomach cancer can cause the same symptoms, such as indigestion, stomach discomfort or pain, bloating after meals, nausea and heartburn [1]; so they cannot be told apart from symptoms, and the only reliable way is an endoscopy with a biopsy [3]. Most of the time these symptoms have a simpler cause [1]. But unexplained weight loss, difficulty swallowing, repeated vomiting, black stools, anaemia, or indigestion that starts at an older age are warning signs and should be checked soon [5, 6].
Key points
- Ulcer and stomach cancer symptoms are alike: stomach cancer usually causes no symptoms at first, and when it does, they mostly resemble indigestion [1].
- A shared cause: the bacterium Helicobacter pylori causes stomach ulcers and is also a major risk factor for stomach cancer; treating it lowers the risk of cancer [2].
- There is no home test for stomach cancer. Breath and stool tests only detect H. pylori, not cancer [3, 7].
- Burping is a normal behaviour, and excessive burping is often a behavioural problem [11]; burping is not one of the recognised symptoms of stomach cancer [1].
- Stomach cancer is common in some parts of the world; in Iran, for example, it is the leading cause of cancer death [12]; if you grew up in a country where stomach cancer is common or you have a family history, your doctor may suggest an endoscopy at a younger age [5].
Stomach ulcer or stomach cancer: how do the symptoms differ?
A stomach ulcer is a sore in the inner lining of the stomach. One of its main causes is the bacterium Helicobacter pylori [2]. Some medicines, such as anti-inflammatory painkillers (ibuprofen, diclofenac), can also cause indigestion [7]. Stomach cancer usually causes no symptoms at first. When it does, they are the same as the symptoms of indigestion: stomach discomfort, bloating after meals, mild nausea, loss of appetite and heartburn. These symptoms have many causes other than cancer [1]. This table shows when each symptom is more of a worry:
| Symptom | In stomach ulcers and indigestion | When it is a worry |
|---|---|---|
| Pain or burning in the upper tummy | A common symptom of indigestion [7] | If it does not improve with medicine and you are 55 or older, or if it comes with weight loss [6] |
| Bloating and fullness after meals, nausea | Common in indigestion [7] | With weight loss, loss of appetite or repeated vomiting [1, 6] |
| Anaemia | May be a sign of slow bleeding in the stomach [3] | Upper tummy pain with anaemia at 55 or older [6] |
| Black stools or vomiting blood | A sign of bleeding; may come from an ulcer or from cancer [1, 7] | Always; heavy bleeding needs attention the same day [7] |
| Difficulty swallowing | Not one of the usual symptoms of indigestion [7] | At any age, have it checked urgently [6] |
| Unexplained weight loss | Not one of the usual symptoms of indigestion [7] | With upper tummy pain, reflux or indigestion at 55 or older: urgent referral [6] |
| Burping a lot | Usually a normal or habitual behaviour [11] | On its own, not a recognised symptom of stomach cancer [1] |
| A bitter taste in the mouth | If it comes with heartburn or acid coming up, it is assessed like indigestion [7] | On its own, not a recognised symptom of stomach cancer [1] |
This table does not replace an examination by a doctor; in most people these symptoms have a benign cause.
Is burping a lot a sign of cancer? And a bitter taste?
Burping is a normal thing the body does. When it becomes excessive, in many people it is a behavioural problem, and doctors treat it with behavioural methods [11]. Burping is not among the symptoms that the US National Cancer Institute lists for stomach cancer [1].
A bitter taste in the mouth is not a recognised symptom of stomach cancer either [1]. If it comes with heartburn or acid coming back up into the mouth, your doctor will assess it in the same way as indigestion and reflux [7]. Burping or a bitter taste is a worry only when it comes with one of the warning signs, such as weight loss, difficulty swallowing, repeated vomiting or black stools [6].
What does stomach cancer feel like?
Stomach cancer pain has no particular character that would let you recognise it. In the early stages, if there are symptoms at all, they are more often stomach discomfort and indigestion than severe pain. Stomach pain tends to appear once the disease has advanced, and it may come with other symptoms such as unexplained weight loss, vomiting, blood in the stool or difficulty swallowing [1].
That is why how bad the pain is does not tell you much. What matters is indigestion that does not improve with medicine, especially from the age of 55, or that comes with warning signs [6]. Read the full list of symptoms in What are the symptoms of stomach cancer?, and about weight loss in Unexplained weight loss: when is it a sign of cancer?
Can a stomach ulcer turn into cancer?
Stomach ulcers and stomach cancer share a cause. In some people the bacterium Helicobacter pylori causes a stomach ulcer, and in others long-lasting inflammation and thinning of the stomach lining (atrophic gastritis), which sometimes slowly progresses to cancer [2]. In a large study in Sweden, people who had had a stomach ulcer developed stomach cancer nearly twice as often as others in the following years; but an ulcer in the duodenum (the first part of the small bowel) was linked to a lower risk [8].
Another important point is that stomach cancer sometimes looks like a simple ulcer at endoscopy. In a study in England, the most common appearance behind which cancer was missed at the first endoscopy was a stomach ulcer [9]. That is why samples are taken from ulcers and any suspicious area during endoscopy [3]. Treating H. pylori lowers the risk of this type of stomach cancer [2]; read: Should I be tested for H. pylori? (Preventing stomach cancer)
How do doctors tell a stomach ulcer from stomach cancer?
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History, examination and tests
Your doctor asks about your symptoms, family history and medicines and examines your tummy. They may ask for a blood test for anaemia and a faecal occult blood test; both can be signs of bleeding in the stomach [3]. Medicines that can cause indigestion or ulcers, such as anti-inflammatory painkillers, are also reviewed [7].
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Endoscopy and biopsy
A thin tube with a camera is passed through the mouth into the oesophagus, stomach and duodenum and shows any abnormal areas. The doctor takes a small piece from any suspicious area so that it can be examined under the microscope. A definite diagnosis of an ulcer or cancer is made from this sample [3].
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If cancer is confirmed
More tests are done to find the stage and choose treatment [3]. Read the details on the stomach cancer page.
Is there a home test for stomach cancer?
No. There is no test you can do at home that detects stomach cancer [3, 4]. In the United States there is no standard screening test for stomach cancer for people at average risk [4], and the diagnosis is made only by endoscopy with a biopsy [3]. Blood tumour marker tests do not work well for finding cancer early either [13]; read: What is a tumour marker and when is it useful?
What does exist is the H. pylori test: a breath test or a stool test [7]. These tests show the bacterium, not cancer. If you take a medicine that lowers stomach acid (such as omeprazole or pantoprazole), you need to stop it 2 weeks before the test for the result to be accurate; do this with your doctor's advice [7].
For people at higher risk, such as those with a family history of stomach cancer or people from countries where stomach cancer is more common, screening with endoscopy may be helpful [4].
Who needs an endoscopy?
Guidelines differ a little, but the main message is the same [5, 6]:
- 60 or older with indigestion: the US and Canadian guideline suggests an endoscopy [5].
- Under 60: usually an H. pylori test first, with treatment if it is positive; if that does not help, an acid-lowering medicine. Warning signs in younger people do not automatically mean an endoscopy, but the doctor decides for each person individually [5].
- Higher risk: if you spent your childhood in a country where stomach cancer is common, or you have a family history, an endoscopy may be suggested at a younger age [5]. In Iran, stomach cancer is the third most common cancer and the leading cause of cancer death [12].
- At any age: difficulty swallowing needs urgent referral [6].
- 55 or older: weight loss with upper tummy pain, reflux or indigestion needs urgent referral; indigestion that does not improve with treatment should also be checked with an endoscopy [6].
Endoscopy is usually safe, but like any procedure it has rare but serious complications, such as bleeding or a hole in the oesophagus or stomach [4].
Can stomach medicines hide the symptoms of cancer?
Acid-lowering medicines such as omeprazole help indigestion and stomach ulcers, and guidelines recommend them [7]. The question is whether these medicines might improve the symptoms of cancer for a while and delay the diagnosis:
- In an older study in England of 116 patients with stomach or oesophageal cancer, cancer was missed at the first endoscopy in a third of those who had taken these medicines beforehand; in a few people a cancerous ulcer had temporarily healed with the medicine [9].
- In a large recent study in five Nordic countries of more than 21,000 patients with stomach cancer, taking these medicines in the 2 years before diagnosis was not linked to more advanced disease or more deaths [10].
The practical point is this: if you have a warning sign, do not use medicine instead of seeing a doctor. If your symptoms improve with medicine but come back after you stop it, or do not improve with it, see your doctor again [6, 7].
What causes stomach cancer?
Stomach cancer has several causes, and many risk factors do not cause cancer themselves but make it more likely [2]. The most important ones are [2]:
- Long-term infection with Helicobacter pylori; a major risk factor, and treating it lowers the risk
- Atrophic gastritis (thinning of the stomach lining after long-term inflammation) and the replacement of stomach cells by cells like those of the bowel
- A family history of stomach cancer in a parent, brother, sister or child, and some inherited syndromes
- Salty, smoked or poorly preserved food and a diet low in fruit and vegetables
- Smoking; stopping lowers the risk over time
- Obesity and reflux, which are linked mainly with cancer of the upper part of the stomach
Having one or more risk factors does not mean you will get stomach cancer [2]. Read about opium: Does opium cause cancer?
When should I call my doctor?
Most indigestion and stomach pain has a simple cause. But in these situations see a doctor within the next few days:
- difficulty swallowing or food sticking, at any age [6]
- unexplained weight loss with upper tummy pain, reflux or indigestion, especially from the age of 55 [6]
- indigestion that does not improve with medicine, from the age of 55 [6]
- new indigestion from the age of 60 [5]
- anaemia on a blood test, or nausea and vomiting with weight loss [6]
- a lump in the upper tummy [6]
Vomiting blood or material that looks like coffee grounds, or black tar-like stools need attention the same day [7]. If they come with dizziness or fainting, or you have sudden severe tummy pain, call your local emergency number.
Frequently asked questions
I have had a stomach ulcer for years. Could it have turned into cancer?
Can gastritis (inflammation of the stomach) turn into cancer?
Many people who have a risk factor such as stomach inflammation never get stomach cancer [2]. But long-lasting inflammation caused by H. pylori leads in some people to thinning of the stomach lining (atrophic gastritis), and this sometimes slowly turns into cancer [2]. Treating H. pylori lowers this risk [2].
I tested positive for H. pylori. Does that mean I have stomach cancer?
No. Many people who carry this bacterium have no symptoms and never get cancer [2]. But because H. pylori is a major risk factor for stomach cancer and treating it lowers the risk, talk to your doctor about treatment [2]. Read: Should I be tested for H. pylori? (Preventing stomach cancer)
I am young and have indigestion. Do I need an endoscopy?
If you are under 60 and have no warning signs, the US and Canadian guideline usually suggests testing and treating H. pylori first, and then an acid-lowering medicine [5]. If you have a family history of stomach cancer or grew up in a country where stomach cancer is common, an endoscopy may be needed sooner [5]. Difficulty swallowing should be checked urgently at any age [6].
Can a blood test show stomach cancer?
I burp a lot. Should I worry about cancer?
Referral for endoscopy and diagnostic points (for doctors)
For physicians
ACG/CAG 2017 (Moayyedi et al.). Patients aged 60 and over with dyspepsia: upper GI endoscopy to exclude organic pathology (conditional recommendation); patients at higher risk (childhood spent in a country with a high incidence of gastric cancer, or a positive family history) may be offered endoscopy at a younger age. Alarm features should not automatically prompt endoscopy in younger patients but should be considered case by case. Under 60: non-invasive H. pylori testing and treatment if positive; if negative or unresponsive, a trial of PPI, then TCA or prokinetic therapy [5].
NICE NG12. Suspected cancer pathway referral for stomach cancer with dysphagia, or aged 55 and over with weight loss and any of upper abdominal pain, reflux or dyspepsia (1.2.7); an upper abdominal mass consistent with stomach cancer (1.2.6). Non-urgent direct-access endoscopy for haematemesis (1.2.8) and, in those aged 55 and over, for treatment-resistant dyspepsia, upper abdominal pain with low haemoglobin, raised platelet count with nausea, vomiting, weight loss, reflux, dyspepsia or upper abdominal pain, or nausea or vomiting with weight loss, reflux, dyspepsia or upper abdominal pain (1.2.9) [6]. NICE CG184: dyspepsia with significant acute GI bleeding, immediate same-day referral (1.3.1); review medicines that can cause dyspepsia (calcium antagonists, nitrates, theophyllines, bisphosphonates, corticosteroids, NSAIDs) and suspend NSAIDs in patients needing referral (1.3.2); a 2-week washout after PPI use before a breath test or stool antigen test (1.4.2) [7].
Gastric ulcer and cancer risk. In the Swedish Inpatient Register cohort (57,936 patients, mean follow-up 9.1 years), the standardised incidence ratio for gastric cancer among 29,287 patients with gastric ulcer, after peaking in the first 3 years, levelled off at 1.8 (95% CI 1.6 to 2.0); it was 1.2 (0.8 to 1.6) for prepyloric ulcer and 0.6 (0.4 to 0.7) for duodenal ulcer after the second year [8].
Acid suppression before endoscopy. In Bramble et al.'s review (116 deaths from oesophageal or gastric adenocarcinoma), 22 of 62 patients on acid suppression versus 1 of 54 on no treatment or antacids alone were diagnosed with benign disease at the index endoscopy; 20 of 45 PPI users versus 2 of 17 H2RA users had a delayed diagnosis; the commonest lesion in missed cases was gastric ulcer, and the ulcer healed on PPI in 6 patients [9]. In a Nordic population-based cohort (21,433 gastric non-cardia adenocarcinomas), heavy and light PPI use in the 2 years before diagnosis was associated with lower 5-year disease-specific mortality (adjusted HR 0.90; 95% CI 0.86 to 0.94, and 0.87; 0.84 to 0.91), and heavy use with a lower risk of metastatic disease (OR 0.70; 0.64 to 0.76) and advanced stage (OR 0.71; 0.56 to 0.89) [10]. In practice, patients with alarm features should have endoscopy without delay, and suspicious lesions, including gastric ulcers, should be biopsied [3, 6, 9].
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References
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- 13Tumor Markers
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