Source: National Cancer Institute Research, www.cancer.gov
Cancerprevention is action taken to lower the chance of getting cancer. By preventing cancer, the number of new cases of cancer in a group or population is lowered. Hopefully, this will lower the number of deaths caused by cancer.
To prevent new cancers from starting, scientists look at risk factors and protective factors. Anything that increases your chance of developing cancer is called a cancer risk factor; anything that decreases your chance of developing cancer is called a cancer protective factor.
Some risk factors for cancer can be avoided, but many cannot. For example, both smoking and inheriting certain genes are risk factors for some types of cancer, but only smoking can be avoided. Regular exercise and a healthy diet may be protective factors for some types of cancer. Avoiding risk factors and increasing protective factors may lower your risk but it does not mean that you will not get cancer.
Different ways to prevent cancer are being studied, including:
The stomach is a J-shaped organ in the upper abdomen. It is part of the digestive system, which processes nutrients (vitamins, minerals, carbohydrates, fats, proteins, and water) in foods that are eaten and helps pass waste material out of the body. Food moves from the throat to the stomach through a hollow, muscular tube called the esophagus. After leaving the stomach, partly-digested food passes into the small intestine and then into the large intestine.
See the following PDQ summaries for more information about stomach cancer:
Since 2005, the number of new cases of stomach cancer in the United States has stayed about the same. Men are twice as likely as women to be diagnosed with stomach cancer.
Stomach cancer is the fourth most common cancer in the world.
The number of deaths from stomach cancer has decreased over many years, especially in the United States. Black men are more than twice as likely as white men to die from stomach cancer.
Avoiding cancerrisk factors may help prevent certain cancers. Risk factors include smoking, being overweight, and not getting enough exercise. Increasing protective factors such as quitting smoking, eating a healthy diet, and exercising may also help prevent some cancers. Talk to your doctor or other health care professional about how you might lower your risk of cancer.
Having any of the following medical conditions may increase the risk of stomach cancer:
Genetic conditions may increase the risk of stomach cancer in people with any of the following:
The risk of stomach cancer may be increased in people who:
Environmental factors that may increase the risk of stomach cancer include:
The risk of stomach cancer is increased in people who come from countries where stomach cancer is common.
Studies show that smoking is linked with an increased risk of stomach cancer. Stopping smoking or never smoking decreases the risk of stomach cancer. Smokers who stop smoking lower their risk of having stomach cancer over time.
Studies show that chronicinfection with Helicobacter pylori (H. pylori) bacteria is linked to an increased risk of stomach cancer. When H. pylori bacteria infects the stomach, the stomach may become inflamed and cause changes in the cells that line the stomach. Over time, these cells become abnormal and may become cancer.
Some studies show that treating H. pylori infection with antibiotics lowers the risk of stomach cancer. More studies are needed to find out whether treating H. pylori infection with antibiotics lowers the number of deaths from stomach cancer or keeps changes in the stomach lining, that can lead to cancer, from getting worse.
Not eating enough fresh fruits and vegetables is linked to an increased risk of stomach cancer. Some studies show that eating fruits and vegetables that are high in vitamin C and beta carotene may lower the risk of stomach cancer. Studies also show that whole-grain cereals, carotenoids, green tea, and substances found in garlic may lower the risk of stomach cancer.
Studies show that eating a diet with a lot of salt may increase the risk of stomach cancer. Many people in the United States now eat less salt to lower their risk of high blood pressure. This may be why rates of stomach cancer have decreased in the U.S.
It is not known if taking certain vitamins, minerals, and other dietary supplements helps lower the risk of stomach cancer. In China, a study of beta carotene, vitamin E, and selenium supplements in the diet showed a lower number of deaths from stomach cancer. The study may have included people who did not have these nutrients in their usual diets. It is not known if increased dietary supplements would have the same effect in people who already eat a healthy diet.
Other studies have not shown that taking dietary supplements such as beta carotene, vitamin C, vitamin E, or selenium lowers the risk of stomach cancer.
Cancer preventionclinical trials are used to study ways to lower the risk of certain types of cancer. Some cancer prevention trials are done with healthy people who have not had cancer but who have an increased risk for cancer. Other prevention trials are done with people who have had cancer and are trying to prevent another cancer of the same type or to lower their chance of developing a new type of cancer. Other trials are done with healthy volunteers who are not known to have any risk factors for cancer.
The purpose of some cancer prevention clinical trials is to find out whether actions people take can prevent cancer. These may include eating fruits and vegetables, exercising, quitting smoking, or taking certain medicines, vitamins, minerals, or food supplements.
Clinical trials are taking place in many parts of the country. Information about clinical trials can be found in the Clinical Trials section of the NCI Web site. Check NCI's list of cancer clinical trials for stomach cancer prevention that are now accepting patients.