Gastric cancer, or stomach cancer, is complex. It has many risk factors. These factors can make it more likely for someone to get the disease. Knowing these factors is key. It helps with early detection and finding the best ways to treat and prevent it. Let’s look at the reasons gastric cancer shows up. We will talk about what you can control and what you can’t in terms of these risks.

So, what is a risk factor? It’s something that can raise your chances of getting an illness. This is true for many diseases, including cancer. Stomach cancer has unique risk factors. Some you can change, and some you can’t. Scientists have identified key risk factors for stomach cancer. Understanding them can help you lower your risk. This way, you can do things to avoid getting gastric cancer.

Helicobacter Pylori Infection

Becoming infected with Helicobacter pylori (H. pylori) is a big cause of gastric cancer, especially in the lower part of the stomach. This bacteria infection is common and can cause long-term inflammation and other stomach lining changes. Over time, these may become pre-cancerous.

The Role of Chronic Inflammation

H. pylori infection can start a long-lasting problem in the stomach. This leads to the stomach lining becoming thin and loss, a condition called atrophic gastritis. This process, along with the long-term inflammation, is critical for the start of gastric cancer.

Atrophic Gastritis and Precancerous Changes

This issue of the stomach lining becoming thin and other changes, like cells transforming into intestine-like cells, are bad signs. They raise the risk of getting stomach cancer. People with stomach cancer often have an H. pylori infection, even though not everyone with this bacteria will develop cancer.

Dietary Factors

The food you eat can change your chances of getting stomach cancer. Some foods make the risk higher, while others can lower it.

Salt-Preserved Foods and Processed Meats

Eating too much salted, pickled, or charcoaled food may raise your risk. These foods often have lots of salt and harmful compounds. This can make stomach cancer more likely.

Lack of Fruits and Vegetables

On the other hand, eating lots of fruits and vegetables can lower your risk. Foods high in citrus fruit, like oranges and lemons, protect against cancer. Vitamin C-rich foods, such as citrus, cabbage, and strawberries, are good for you too.

Many healthy compounds in these foods fight off cancer. These include flavonoids, hesperetin, and naringenin. They help keep your stomach healthy.

Vegetables, especially cruciferous vegetables, are great for fighting cancer too. Eating plenty of vitamin A and carotenoids also makes stomach cancer less likely.


Lifestyle Choices

Your lifestyle plays a big part in your risk for gastric cancer. This includes if you smoke, how much you drink, and if you use tobacco. Knowing these risks can help you make changes to lower your risk.

Tobacco Use and Smoking

Smoking makes the risk of gastric cancer higher. Especially for cancers in the upper stomach near the throat. The chance of stomach cancer is twice as likely for people who smoke. Quitting reduces this risk, which is key to stop gastric cancer.

Alcohol Consumption

Drinking alcohol also hikes up the risk for stomach cancer. This is true for those who have 3 or more drinks daily. Cutting back on alcohol or stopping completely can lower this risk.

what causes gastric cancer

Gastric cancer, or stomach cancer, may affect anyone. However, the chance of getting it goes up as you get older. People usually get this cancer when they are 68 years old or older. Sixty percent of these cases are in those over 65. Men are more likely to get stomach cancer than women.

Age and Gender Differences

Younger people can also get stomach cancer, but it’s rarer. The risk increases as you get older. It’s most often found in people in their 60s, 70s, and 80s. Men are more at risk than women. This could be because men tend to smoke and drink more.

Ethnicity and Geographic Variations

Stomach cancer varies by where you live and your ethnicity. It’s more common in some parts of Asia, Eastern Europe, and South America. There, the rates are higher than in the United States and the West. Within the U.S., non-White people, like Black, Hispanic, and Asian, have a greater risk of getting it than White people. Many things, like genes, lifestyle, and what’s in your environment, can affect these rates.

Obesity and Overweight

Too much body weight, like being overweight or obese, is a big risk for stomach cancer. In the United States, over 31% of adults were obese in 2020. This number has gone up a lot from 2011.

In kids and teens, this problem is getting worse too. The percentage of young people with obesity grew from 16.9% to 19.3% from 2011-2012 to 2017-2018.

The link between obesity, being overweight, and stomach cancer is complicated. It varies by where people live. Being obese can raise the risk of cancer in the upper part of the stomach. But, just being overweight might not do that.

Some research says the link between obesity and stomach cancer is stronger for men and people who are not Asian. Studies show that obesity increases the chance of getting stomach cancer. This risk might be 10% to 29% higher if you’re obese.

Research points to a higher chance of getting stomach cancer near the top of the stomach if you are overweight or obese. You need a healthy weight to lessen this risk.

Previous Stomach Surgery

Having stomach surgery before can raise your chances of getting gastric cancer.

Partial Gastrectomy and Reflux

After having part of their stomach removed, people might make less stomach acid. This can let bad bacteria grow, leading to changes that could turn into cancer. Also, stomach bile leaking back in after the surgery might help cancer grow.

This has been seen with surgeries done for peptic ulcer disease.

Partial Gastrectomy and Reflux


Percentage of gastric cancer cases associated with tobacco smoking17%
Percentage of gastric cancer cases linked to H. pylori infection6%
Percentage of gastric cancer cases with a family history3%
Estimated percentage of gastric cancer cases with bile reflux as a cancer-promoting factor18%

Precancerous Conditions

Some conditions can make you more likely to get stomach cancer. These include certain types of stomach polyps and pernicious anemia.

Stomach Polyps and Pernicious Anemia

Adenomatous polyps are a type of stomach polyp. If you don’t treat them, they might become stomach cancer. Other polyps, like hyperplastic or inflammatory, usually don’t raise the cancer risk much. Additionally, pernicious anemia, which stops your body from absorbing vitamin B12 well, can make your risk of stomach cancer higher.

Menetrier Disease (Hypertrophic Gastropathy)

Menetrier disease makes your stomach folds big and produces too much mucus. It’s pretty rare and doesn’t directly lead to cancer. Still, people with this condition have a higher risk of stomach cancer than others.

Inherited Cancer Syndromes

Many gastric cancer cases happen for unknown reasons. But, around 5% to 10% might be linked to genes. It’s important to know this for spotting those at high risk early.

Hereditary Diffuse Gastric Cancer (HDGC)

HDGC comes from changes in the CDH1 gene. This gene makes E-cadherin, a key protein in cell adhesion. People with HDGC may get stomach cancer younger than others.

Lynch Syndrome (HNPCC)

Lynch syndrome, or HNPCC, raises stomach cancer risk too. It’s due to DNA mismatch repair gene changes like MLH1 and MSH2. This syndrome links to both colorectal and gastric cancers.

Other Inherited Conditions

More conditions can also raise your chance of stomach cancer. These include FAP, GAPPS, LFS, PJS, and JPS. Even genes like BRCA1 and BRCA2 might play a part.

Learning about these conditions helps us understand who’s at risk. And, we can then do better at keeping them healthy through checks and early actions.

Occupational Exposures

Research shows some jobs are linked to a higher chance of getting gastric cancer. This includes jobs in coal, metal, and rubber production. Also, jobs with a lot of dust, like wood processing, and those in very hot places are risky. But the evidence for these is not as clear.

More study is needed to find out why these jobs might raise the risk of gastric cancer. Some suggest checking for early signs of cancer in these workplaces might help. This could be a way to tackle the problem of cancer at work.

Recent studies show a few worrying things. For example, stomach cancer rates are higher in Ontario miners. This hints that mining jobs might carry certain risks.

In the UK, steel factory workers are also in a risky spot. They have a higher chance of dying from stomach and lung cancers. This points to dangers in the steel industry.

In Finland, workers in metal plants face similar risks, like those in copper/nickel smelters. People working with lead, like in battery plants, also might face health dangers.

Gastric cancer risk seems high for a long list of jobs, including construction, quarry work, mining, and rubber work. This risk might even change with how educated or what job class someone is in.

Studies often find jobs like firefighting, fishing, and carpentry are linked to higher gastric cancer risks. Besides, workers in the meat, rubber, and leather shoe industries might face extra risks.

Causes of this higher risk include breathing in coal, metal dust, and wood particles. Also, farmers and those exposed to certain chemicals have a higher risk. Researchers use complex methods to link specific jobs to cancer risks.

Blood Type

New studies show your blood type might affect how likely you are to get stomach cancer. Some research has found that certain blood types might have a higher risk for gastric cancer.

A 1953 study first noticed a link between stomach cancer and blood type. In 1958, more research found that your blood type might impact your chances of getting gastric cancer. Then, a 2010 study discovered a connection between blood type and risk for both gastric cancer and peptic ulcers.

In 2011, a new study connected your ABO blood type to the risks of stomach cancer, atrophic gastritis, and Helicobacter pylori infection. Around the same time, a big look at the data involving 18,000 cases and 58,000 controls found links between blood types, stroke, and several cancer types, including gastric cancer.

Surprisingly, those with type A blood seem more likely to get gastric cancer. Yet, we don’t fully understand the reasons. But, scientists are working to find out how blood types might be involved in stomach cancer risks.


While the causes of gastric cancer are complex, you can lower your risk. Follow a healthy lifestyle with lots of fruits and vegetables. It’s important to stop smoking and cut down on alcohol.

Seeing your doctor regularly helps find gastric cancer early. This greatly improves how well it can be treated.

If gastric cancer runs in your family, talk to your doctor. They’ll help with advice on how to watch for the disease. And they can guide on early steps if problems are found.

Being proactive with prevention and staying in touch with your health team is vital. This lets you play an active part in staying healthy. Remember, finding gastric cancer early and treating it quickly are crucial.


What are the risk factors for gastric cancer?

Infection with Helicobacter pylori (H. pylori) bacteria is a big risk factor. Eating lots of salt-preserved food and smoking also increase your risk. If you’re overweight or have had stomach surgery, your risk goes up too. Age, gender, ethnicity, family history, and blood type also matter.

How does Helicobacter pylori infection contribute to gastric cancer?

When you have H. pylori for a long time, it can cause inflammation in your stomach lining. This might lead to cancer, especially in the stomach’s lower area.

What dietary factors increase the risk of gastric cancer?

Eating too much salted food and processed meats is bad. But, eating lots of fruits and vegetables can lower your risk.

How do lifestyle factors like smoking and alcohol affect gastric cancer risk?

Smoking is really bad for your stomach, especially for the upper part. It can double your risk of cancer. Drinking alcohol might also be risky, but we’re not completely sure yet.

Are there any differences in gastric cancer risk based on age, gender, and ethnicity?

Gastric cancer risk goes up as you get older, mostly between your 60s and 80s. Men get it more often than women. Some groups have a higher risk, but we’re not sure why.

How does being overweight or obese impact gastric cancer risk?

If you’re overweight, you have more chance of getting cancer in the upper part of your stomach. This is especially true near your esophagus.

What is the link between previous stomach surgery and gastric cancer risk?

Having stomach surgery in the past, even for non-cancer issues like ulcers, can raise your risk. This might be because of changes in stomach acid and bile reflux.

Can precancerous conditions increase the risk of gastric cancer?

Yes. Some precancerous conditions in the stomach can turn into cancer. But, most stomach polyps don’t really raise your risk much.

Are there any inherited genetic syndromes linked to gastric cancer?

Some people inherit gene mutations that make them more likely to get gastric cancer. Conditions like HDGC and Lynch syndrome increase your risk, though they’re rare.

Are there any occupational factors that increase the risk of gastric cancer?

Working in coal, metal, or rubber industries is linked to a higher risk of gastric cancer. But, we’re still not sure why these jobs might make cancer more likely.

Is there a link between blood type and gastric cancer risk?

We don’t know why, but people with type A blood seem to have a higher risk of gastric cancer. This is compared to others with different blood types.

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