cancer.org | 1.800.227.
2345
Stomach Cancer Causes, Risk Factors,
and Prevention
Learn about the risk factors for stomach cancer and what you might be able to do to
help lower your risk.
Risk Factors
A risk factor is anything that increases your chances of getting a disease such as
cancer. Learn more about the risk factors for stomach cancer.
● Stomach Cancer Risk Factors
● What Causes Stomach Cancer?
Prevention
There is no sure way to prevent stomach cancer. But there are things you can do that
might lower your risk. Learn more.
● Can Stomach Cancer Be Prevented?
Stomach Cancer Risk Factors
● Sex
● Age
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● Ethnicity
● Geography
● Helicobacter pylori infection
● Being overweight or obese
● Diet
● Alcohol use
● Tobacco use
● Previous stomach surgery
● Some types of stomach polyps
● Pernicious anemia
● Menetrier disease (hypertrophic gastropathy)
● Inherited cancer syndromes
● A family history of stomach cancer
● Common variable immune deficiency (CVID)
● Epstein-Barr virus (EBV) infection
● Certain occupations
● Having type A blood
A risk factor is anything that raises your chances of getting a disease such as cancer.
Different cancers have different risk factors. Some risk factors, like smoking, can be
changed. Others, like a person’s age or family history, can’t be changed.
But having a risk factor, or even several risk factors, does not mean that you will get the
disease. Many people with one or more risk factors never get cancer, while others who
get cancer may have had few or no known risk factors.
Scientists have found several risk factors that make a person more likely to get stomach
cancer. Some of these can be controlled, but others cannot.
Sex
Stomach cancer is more common in men than in women.
Age
Stomach cancer can occur in younger people, but the risk goes up as a person gets
older. Most people diagnosed with stomach cancer are in their 60s, 70s, or 80s.
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Ethnicity
In the United States, stomach cancer is more common in Hispanic Americans, African
Americans, Native Americans, Asian Americans, and Pacific Islanders than it is in non-
Hispanic White people.
Geography
Worldwide, stomach cancer is more common in East Asia, Eastern Europe, and South
and Central America. This disease is less common in Africa and North America.
Helicobacter pylori infection
Infection with Helicobacter pylori (H pylori) bacteria seems to be a major cause of
stomach cancer, especially cancers in the lower (distal) part of the stomach. Long-term
infection of the stomach with this germ may lead to atrophic gastritis and other pre-
cancerous changes of the inner lining of the stomach.
People with stomach cancer have a higher rate of H pylori infection than people without
this cancer. H pylori infection is also linked to some types of lymphoma of the stomach.
Even so, most people who carry this germ in their stomach never develop cancer.
Being overweight or obese
Being overweight or obese is linked with an increased risk of cancers of the cardia (the
upper part of the stomach near the esophagus).
Diet
Stomach cancer risk is increased in people whose diets include large amounts of foods
preserved by salting, such as salted fish and meat and pickled vegetables.
Eating processed, grilled, or charcoaled meats regularly appears to increase risk of non-
cardia stomach cancers.
Eating few or no fruits likely increases the risk of stomach cancer. On the other hand,
eating lots of fresh fruits (especially citrus fruits) and raw vegetables appears to lower
the risk of stomach cancer.
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Alcohol use
Alcohol use probably increases the risk of stomach cancer. The evidence for this link is
strongest for people who have 3 or more drinks per day.
Tobacco use
Smoking increases stomach cancer risk, particularly for cancers of the upper part of the
stomach near the esophagus. The rate of stomach cancer is about doubled in people
who smoke.
Previous stomach surgery
Stomach cancers are more likely to develop in people who have had part of their
stomach removed to treat non-cancerous diseases such as ulcers. This might be
because the stomach makes less acid, which allows more harmful bacteria to be
present. Reflux (backup) of bile from the small intestine into the stomach after surgery
might also add to the increased risk. These cancers typically develop many years after
the surgery.
Some types of stomach polyps
Polyps are non-cancerous growths on the lining of the stomach. Most types of polyps
(such as hyperplastic polyps or inflammatory polyps) do not seem to increase a
person’s risk of stomach cancer much, if at all. But adenomatous polyps – also called
adenomas – can sometimes develop into cancer.
Pernicious anemia
Certain cells in the stomach lining normally make a substance called intrinsic
factor(IF)that the body needs to absorb vitamin B12 from foods. People without enough
IF may end up with a vitamin B12 deficiency, which affects the body’s ability to make
new red blood cells and can cause other problems as well. This condition, called
pernicious anemia, can be caused by certain autoimmune conditions, as well as by
some types of stomach surgery. Along with anemia (having too few red blood cells),
people with this disease have an increased risk of stomach cancer.
Menetrier disease (hypertrophic gastropathy)
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In this condition, excess growth of the stomach's inner lining causes large folds in the
lining and leads to low levels of stomach acid. Because this disease is very rare, it is not
known exactly how much this increases the risk of stomach cancer.
Inherited cancer syndromes
Some people inherit gene mutations (changes) from their parents that lead to conditions
that can raise their risk of stomach cancer. These inherited syndromes account for only
a small percentage of stomach cancers worldwide.
Hereditary diffuse gastric cancer (HDGC)
This inherited syndrome greatly increases the risk of developing stomach cancer. This
condition is rare, but the lifetime stomach cancer risk among affected people is up to
70%. Women with this syndrome also have an increased risk of invasive lobular breast
cancer. This syndrome is most often caused by mutations in the CDH1 gene.
Lynch syndrome (hereditary non-polyposis colorectal cancer, or HNPCC)
Lynch syndrome (formerly known as HNPCC) is an inherited genetic disorder that
increases the risk ofcolorectal cancer, stomach cancer, and some other cancers. This
syndrome is caused by mutations in one of the mismatch repair (MMR) genes, such as
MLH1 or MSH2. These genes normally help repair DNA that has been damaged.
Familial adenomatous polyposis (FAP)
People with FAP get many polyps in the colon, and sometimes in the stomach and
intestines, starting at an early age. People with this syndrome have a very high risk of
getting colorectal cancer and a slightly increased risk of getting stomach cancer. FAP is
caused by mutations in the APC gene.
Gastric adenoma and proximal polyposis of the stomach (GAPPS)
This rare condition is caused by a mutation in a specific part of the APC gene. People
with GAPPS develop many polyps in the stomach and have an increased risk of
stomach cancer.
Li-Fraumeni syndrome
People with this syndrome have an increased risk of several types of cancer, including
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developing stomach cancer at a relatively young age. Li-Fraumeni syndrome is caused
by a mutation in the TP53 gene.
Peutz-Jeghers syndrome (PJS)
People with this condition develop polyps in the stomach and intestines, as well as in
other areas including the nose, the airways of the lungs, and the bladder. The polyps in
the stomach and intestines are called hamartomas. They can cause problems like
bleeding or blockage of the intestines. PJS can also cause dark freckle-like spots on the
lips, inner cheeks and other areas. People with PJS have an increased risk of several
types of cancer, including cancers of the colon, pancreas, stomach, and breast. This
syndrome is caused by mutations in the STK11 gene.
A family history of stomach cancer
People with first-degree relatives (parents, siblings, or children) who have had stomach
cancer are more likely to develop this disease, even without one of the inherited cancer
syndromes described above. Still, most people who get stomach cancer do not have a
family history of it.
Common variable immune deficiency (CVID)
In people with CVID, the immune system can’t make enough antibodies to help protect
against germs. This can lead to frequent infections as well as other problems, including
atrophic gastritis and pernicious anemia. People with CVID are more likely to get gastric
lymphoma and stomach cancer.
Epstein-Barr virus (EBV) infection
Epstein-Barr virus causes infectious mononucleosis (also called mono). Most people
are infected with this virus at some time in their lives, usually as children or teens.
EBV has been linked to nasopharyngeal cancer and to some forms of lymphoma. It is
also found in the cancer cells of about 5% to 10% of people with stomach cancer,
although it isn’t yet clear if the virus actually causes stomach cancer. Stomach cancers
linked to EBV tend to be slower growing and have less of a tendency to spread.
Certain occupations
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Workers in the coal, metal, and rubber industries seem to have a higher risk of getting
stomach cancer.
Having type A blood
Blood type groups refer to certain substances that are normally present on the surface
of red blood cells and some other types of cells. These groups are important in
matching blood for transfusions. For unknown reasons, people with type A blood have a
higher risk of getting stomach cancer.
Hyperlinks
1. www.cancer.org/cancer/types/stomach-cancer/causes-risks-prevention/what-
causes.html
2. www.cancer.org/cancer/risk-prevention/diet-physical-activity/alcohol-use-and-
cancer.html
3. www.cancer.org/cancer/risk-prevention/tobacco/health-risks-of-
tobacco/smokeless-tobacco.html
4. www.cancer.org/cancer/types/breast-cancer.html
5. www.cancer.org/cancer/types/colon-rectal-cancer.html
6. www.cancer.org/cancer/types/colon-rectal-cancer.html
7. www.cancer.org/cancer/types/pancreatic-cancer.html
8. www.cancer.org/cancer/types/stomach-cancer/causes-risks-prevention/what-
causes.html
9. www.cancer.org/cancer/types/nasopharyngeal-cancer.html
10. www.cancer.org/cancer/types/lymphoma.html
References
Chan AO, Wong B. Epidemiology of gastric cancer. UpToDate. 2020. Accessed at
https://www.uptodate.com/contents/epidemiology-of-gastric-cancer on June 19, 2020.
Chan AO, Wong B. Risk factors for gastric cancer. UpToDate. 2020. Accessed at
https://www.uptodate.com/contents/risk-factors-for-gastric-cancer on June 19, 2020.
Dhalla F, da Silva SP, Lucas M, Travis S, Chapel H. Review of gastric cancer risk
factors in patients with common variable immunodeficiency disorders, resulting in a
proposal for a surveillance programme. Clin Exp Immunol. 2011;165:17.
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Jasperson KW, Patel SG, Ahnen DJ. APC-associated polyposis conditions. In: Adam
MP, Ardinger HH, Pagon RA, et al., eds. GeneReviews® [Internet]. Last updated 2017.
Accessed at https://www.ncbi.nlm.nih.gov/books/NBK1345/ on June 22, 2020.
Kaurah P, Huntsman DG. Hereditary diffuse gastric cancer. In: Adam MP, Ardinger HH,
Pagon RA, et al., eds. GeneReviews® [Internet]. Last updated 2018. Accessed at
https://www.ncbi.nlm.nih.gov/books/NBK1139/ on June 22, 2020.
Mahachai V, Graham DY, Odze RD. Gastric polyps. UpToDate. 2020. Accessed at
https://www.uptodate.com/contents/risk-factors-for-gastric-cancer on June 19, 2020.
Masciari S, Dewanwala A, Stoffel EM, et al. Gastric cancer in individuals with Li-
Fraumeni syndrome. Genet Med. 2011;13:651–657.
National Cancer Institute. SEER Cancer Stat Facts: Stomach Cancer. 2020. Accessed
at https://seer.cancer.gov/statfacts/html/stomach.html on June 19, 2020.
Online Mendelian Inheritance in Man® (OMIM). Lynch syndrome. 2019. Accessed at
https://omim.org/entry/120435 on June 22, 2020.
Online Mendelian Inheritance in Man® (OMIM). Peutz-Jeghers syndrome. 2019.
Accessed at https://omim.org/entry/175200 on June 22, 2020.
Rock CL, Thomson C, Gansler T, et al. American Cancer Society guideline for diet and
physical activity for cancer prevention. CA Cancer J Clin. 2020;70(4).
doi:10.3322/caac.21591. Accessed at
https://onlinelibrary.wiley.com/doi/full/10.3322/caac.21591 on June 19, 2020.
Sousa H, Pinto-Correia AL, Medeiros R, Dinis-Ribeiro M. Epstein-Barr virus is
associated with gastric carcinoma: The question is what is the significance? World J
Gastroenterol. 2008;14:4347–4351.
World Cancer Research Fund/American Institute for Cancer Research. Continuous
Update Project Expert Report 2018. Diet, Nutrition, Physical Activity and Stomach
Cancer. Accessed at https://www.wcrf.org/sites/default/files/Stomach-cancer-report.pdf
on June 19, 2020.
Last Revised: January 22, 2021
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What Causes Stomach Cancer?
● Pre-cancerous changes in the stomach
● Changes in genes (DNA) in stomach cancer cells
There are many known risk factors for stomach cancer (also called gastric cancer), but
often it's not clear exactly how these factors might affect how cells in the stomach
become cancer cells. This is the subject of ongoing research.
Pre-cancerous changes in the stomach
Several changes thought to be pre-cancerous can occur in the inner lining of the
stomach.
In atrophic gastritis, the normal gland cells of the stomach are either fewer or absent.
There is also some degree of inflammation (in which the stomach cells are damaged by
cells of the immune system). Atrophic gastritis is often caused by infection with H pylori
bacteria (see below). It can also be caused by an autoimmune reaction, in which a
person’s immune system attacks the cells lining the stomach. Some people with this
condition go on to develop pernicious anemia or other stomach problems, including
cancer.
Another possible pre-cancerous change is intestinal metaplasia. In this condition, the
cells that normally line the stomach are replaced by cells that look like the cells that
usually line the intestine. People with this condition often have chronic atrophic gastritis
as well. This might also be related to H pylori infection.
Both atrophic gastritis and intestinal metaplasia can lead to having too few gland cells,
which would normally secrete substances that help protect the cells in the stomach’s
inner lining. Damage to the DNA inside these cells can sometimes lead to dysplasia, in
which the cells become larger and very abnormal looking (more like cancer cells). In
some cases, dysplasia can then progress to stomach cancer.
Changes in genes (DNA) in stomach cancer cells
Recent research has provided clues on how some stomach cancers form. For instance,
H pylori bacteria, particularly certain subtypes, can convert substances in some foods
into chemicals that cause mutations (changes) in the DNA of the cells in the stomach
lining. This may help explain why certain foods such as preserved meats increase a
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person’s risk for stomach cancer. On the other hand, some of the foods that might lower
stomach cancer risk, such as fruits and vegetables, contain antioxidants (like vitamins A
and C) that can block substances that damage a cell’s DNA.
Stomach cancers, like other cancers, are caused by changes in the DNA inside cells.
DNA is the chemical that carries our genes, which control how our cells function. We
look like our parents because they are the source of our DNA. But DNA affects more
than how we look.
Some genes control when cells grow, divide into new cells, and die:
● Genes that normally help cells grow, divide, and stay alive can sometimes change
to become oncogenes.
● Genes that help keep cell division under control, repair mistakes in DNA, or cause
cells to die at the right time are called tumor suppressor genes.
Cancers can be caused by DNA changes that keep oncogenes turned on, or that turn
off tumor suppressor genes.
Inherited versus acquired gene mutations
Inherited mutations in some genes (as explained in Stomach Cancer Risk Factors)
can increase a person’s stomach cancer risk. But these are thought to cause only a
small percentage of stomach cancers.
Most of the gene changes that lead to stomach cancer occur after birth. Some of these
acquired mutations might be caused by risk factors such as H pylori infection or
tobacco use. But other gene changes may just be random events that sometimes
happen inside cells, without having an outside cause.
Hyperlinks
1. www.cancer.org/cancer/types/stomach-cancer/causes-risks-prevention/risk-
factors.html
2. www.cancer.org/cancer/types/stomach-cancer/causes-risks-prevention/risk-
factors.html
References
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Ku GY, Ilson DH. Chapter 72: Cancer of the Stomach. In: Niederhuber JE, Armitage JO,
Doroshow JH, Kastan MB, Tepper JE, eds. Abeloff’s Clinical Oncology. 6th ed.
Philadelphia, Pa: Elsevier; 2020.
Goldberg RM. Pathology and molecular pathogenesis of gastric cancer. UpToDate.
2020. Accessed at https://www.uptodate.com/contents/pathology-and-molecular-
pathogenesis-of-gastric-cancer on June 20, 2020.
Last Revised: January 22, 2021
Can Stomach Cancer Be Prevented?
● Diet, nutrition, body weight, physical activity, and alcohol use
● Not smoking
● Treating H pylori infection
● Aspirin use
● For people at greatly increased risk
There is no sure way to prevent stomach cancer (also known as gastric cancer), but
there are things you can do that could lower your risk.
Diet, nutrition, body weight, physical activity, and alcohol use
Being overweight or obese increases the risk of some types of stomach cancer, so
getting to and staying at a healthy weight might lower your risk.
Getting regular physical activity might also help lower your risk of stomach cancer.
Aside from possible effects on stomach cancer risk, staying at a healthy weight and
being active may also lower your risk of several other cancers and health problems.
A diet that includes plenty of fresh fruits and vegetables probably also lowers stomach
cancer risk. Citrus fruits (such as oranges, lemons, and grapefruit) may be especially
helpful, but be aware that grapefruit and grapefruit juice can change the blood levels of
certain drugs you take. Talk to your health care team about this before adding grapefruit
to your diet.
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The American Cancer Society recommends that people follow a healthy eating
pattern, which includes a variety of colorful fruits and vegetables and whole grains, and
avoids or limits red and processed meats, sugar-sweetened beverages, and highly
processed foods.
Alcohol use probably increases the risk of stomach cancer, so avoiding or limiting
alcohol might lower your risk.
For more on diet, body weight, physical activity, and alcohol use, see the American
Cancer Society Guideline for Diet and Physical Activity for Cancer Prevention.
Studies that have looked at other dietary factors, such as taking dietary supplements
or drinking tea (particularly green tea) have not led to firm conclusions when it comes
to lowering stomach cancer risk. Further research is needed in these areas.
Not smoking
Smoking can increase the risk of cancers of the upper stomach (the portion closest to
the esophagus). Tobacco use increases the risk for many other types of cancer as well.
If you don’t use tobacco, don’t start. If you already do and want help quitting, call the
American Cancer Society at 1-800-227-2345.
Treating H pylori infection
It's not yet clear if people whose stomach linings are chronically infected with the H
pylori bacteria but who do not have any symptoms should be treated with antibiotics.
This is a topic of current research. Some studies have suggested that giving antibiotics
to people with H pylori infection might lower the number of pre-cancerous lesions in the
stomach and reduce the risk of developing stomach cancer. But not all studies have
found this.
While it’s not yet clear if all people with H pylori infection should be treated, some
research has shown that it might be helpful to treat people with H pylori who are also at
higher risk for stomach cancer for other reasons, such as having a close relative with
stomach cancer.
More research is needed to be sure that treating other groups of people with H
pylori infection can lower stomach cancer risk.
If your doctor thinks you might have H pylori infection, there are several ways to test for
this, including a breath test, a blood test, a stool test, and an endoscopy procedure, in
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which a biopsy is done. (See Tests for Stomach Cancer.)
Aspirin use
Using aspirin or other non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen
or naproxen seems to lower the risk of stomach cancer. These medicines can also
lower the risk of developing colon polyps and colon cancer. But they can also cause
serious (and even life-threatening) internal bleeding and other potential health risks in
some people.
Most doctors consider any reduced cancer risk an added benefit for people who take
these drugs for other reasons, such as to treat arthritis. But doctors do not routinely
recommend taking NSAIDs specifically to prevent stomach cancer. Studies have not yet
determined for which people the benefits of lowering cancer risk would outweigh the
risks of bleeding complications.
For people at greatly increased risk
Hereditary diffuse gastric cancer (HDGC) is a rare inherited condition in which people
have a greatly increased risk of stomach cancer, which often develops at a fairly early
age. This rare syndrome is most often caused by an inherited mutation in the CDH1
gene.
It's very important to recognize people and families with this inherited syndrome,
because most people who have it will develop stomach cancer. Families with HDGC
typically have two or more close relatives who develop stomach cancer (usually the
diffuse type), and/or at least one person who is diagnosed before age 50. Some family
members might also develop invasive lobular breast cancer.
Doctors often refer people who might have HDGC to a genetics professional, so they
can discuss possibly getting genetic testing. If testing is done and shows a person has a
mutation (abnormal change) in the CDH1 gene, doctors often recommend they consider
having their stomach removed (typically between the ages of 20 and 30) before cancer
develops. However, this operation (called a total gastrectomy) can lead to long-term
changes in the way a person eats.
Some other hereditary cancer syndromes are also linked with an increased risk for
stomach cancer, including Lynch syndrome, familial adenomatous polyposis (FAP),
Li-Fraumeni syndrome, and Peutz-Jeghers syndrome. The risk of stomach cancer
with these syndromes is not nearly as high as it is with HDGC, so removal of the
stomach is not typically recommended for people who have these syndromes. However,
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doctors might recommend getting regular tests to try to find stomach cancer early in
some of these people.
Hyperlinks
1. www.cancer.org/cancer/risk-prevention/diet-physical-activity/acs-guidelines-
nutrition-physical-activity-cancer-prevention.html
2. www.cancer.org/cancer/risk-prevention/tobacco/guide-quitting-smoking.html
3. www.cancer.org/cancer/types/stomach-cancer/detection-diagnosis-staging/how-
diagnosed.html
4. www.cancer.org/cancer/types/colon-rectal-cancer.html
5. www.cancer.org/cancer/types/stomach-cancer/about/what-is-stomach-cancer.html
6. www.cancer.org/cancer/risk-prevention/genetics/genetic-testing-for-cancer-
risk/understanding-genetic-testing-for-cancer.html
7. www.cancer.org/cancer/types/stomach-cancer/causes-risks-prevention/risk-
factors.html
8. www.cancer.org/cancer/types/stomach-cancer/detection-diagnosis-
staging/detection.html
References
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systematic review. Gastric Cancer. 2008;11:23–32.
Benusiglio PR, Malka D, Rouleau E, et al. CDH1 germline mutations and the hereditary
diffuse gastric and lobular breast cancer syndrome: A multicentre study. J Med Genet.
2013;50(7):486-489.
Bosetti C, Santucci C, Gallus S, Martinetti M, LaVecchia C. Aspirin and the risk of
colorectal and other digestive tract cancers: An updated meta-analysis through 2019.
Ann Oncol. 2020;31(5):558-568.
Choi IJ, Kim CG, Lee JY, et al. Family history of gastric cancer and Helicobacter pylori
treatment. N Engl J Med. 2020;382(5):427-436.
Hebbard P, Schrader KA. Hereditary diffuse gastric cancer. UpToDate. 2020. Accessed
at https://www.uptodate.com/contents/hereditary-diffuse-gastric-cancer on June 24,
2020.
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National Cancer Institute. Stomach (Gastric) Cancer Prevention (PDQ®). 2020.
Accessed at https://www.cancer.gov/types/stomach/hp/stomach-prevention-pdq on
June 24, 2020.
Rock CL, Thomson C, Gansler T, et al. American Cancer Society guideline for diet and
physical activity for cancer prevention. CA Cancer J Clin. 2020;70(4).
doi:10.3322/caac.21591. Accessed at
https://onlinelibrary.wiley.com/doi/full/10.3322/caac.21591 on June 9, 2020.
Last Revised: January 22, 2021
Written by
The American Cancer Society medical and editorial content team
(https://www.cancer.org/cancer/acs-medical-content-and-news-staff.html)
Our team is made up of doctors and oncology certified nurses with deep knowledge of
cancer care as well as journalists, editors, and translators with extensive experience in
medical writing.
American Cancer Society medical information is copyrighted material. For reprint
requests, please see our Content Usage Policy (www.cancer.org/about-
us/policies/content-usage.html).
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