什么是癌症预防？
癌症预防旨在降低患癌几率。通过预防癌症，人群中新增患癌病例减少。希望这一举措将减少由癌症所导致的死亡。
为了预防癌症新发，科学家研究癌症的危险因素和保护因素。癌症的危险因素指任何增加患癌几率的因素；而任何降低患癌几率的因素被称为癌症的保护因素。
有些致癌的危险因素可以避免，有些则无法避免。例如，吸烟及某些基因遗传都是导致某些类型癌症的危险因素，但只有吸烟是可以避免的因素。定期运动和健康饮食可能是某些类型癌症的保护因素。避免危险因素，增加保护因素可能降低患癌风险，但是这并不意味着您不会患上癌症。
科学家们正在研究各种预防癌症的方法，包括：
What is prevention?
Cancer prevention 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:
关于胃癌的基本信息
胃癌是指胃部形成恶性（癌）细胞的疾病。
胃位于上腹部，呈J形，是消化系统的一部分。消化系统可以处理摄入所食物中的营养素（维生素、矿物质、碳水化合物、脂肪、蛋白质和水），并协助将废物排出体外。食物从咽经一中空的肌性管道进入胃，此管道名为食管。部分消化的食物离开胃部后进入小肠随后进入大肠。
食管和胃是上消化道（消化）系统的一部分。
更多有关胃癌的信息请参见以下PDQ总结：
自2005年以来，美国的胃癌新发病例数一直保持在同一水平。
自2005年以来，美国的胃癌新发病例数一直保持在同一水平。男性诊断出胃癌的几率是女性的两倍。
胃癌是世界上第四大常见癌症。
多年来，因胃癌而死亡的人数有所减少，特别是在美国。黑人死于胃癌的可能性是白人的两倍以上。
General Information About Stomach Cancer
Stomach (gastric) cancer is a disease in which malignant (cancer) cells form in the stomach.
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.
The esophagus and stomach are part of the upper gastrointestinal (digestive) system.
See the following PDQ summaries for more information about stomach cancer:
In the United States, the number of new cases of stomach cancer has stayed about the same since 2005.
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.
胃癌预防
避免危险因素和增加保护因素可能有助于预防胃癌。
避免癌症危险因素可能有助于预防某些癌症。危险因素包括吸烟、超重和缺乏锻炼。增加保护因素，如戒烟和锻炼，也可能有助于预防某些癌症。请向您的医生或其他医疗保健专业人员咨询有关如何降低您患癌危险的信息。
胃癌的危险因素如下：
某些病症
患有以下任何一种病症都可能增加患胃癌的风险：
某些遗传状况
下述遗传状况可能会增加患胃癌的风险：
饮食
下述人群患胃癌风险可能会增加：
环境诱因
下列环境因素可能会增加患胃癌风险：
来自胃癌发病率高的国家的人患胃癌的危险会增加。
下列保护因素可能减少患胃癌风险：
戒烟
研究表明吸烟与患胃癌的危险增加有关。戒烟或者从不吸烟可以降低患胃癌的危险。吸烟者戒烟后患胃癌的危险会随着时间的推移而降低。
治疗幽门螺杆菌感染
研究表明幽门螺杆菌（H.pylori）慢性感染与患胃癌的危险增加有关。胃部感染幽门螺杆菌，可能引发炎症并且使得胃内膜细胞发生改变。随着时间推移，这些细胞变成异常细胞并且可能癌变。
一些研究表明，用抗生素治疗幽门螺杆菌感染可降低患胃癌的危险。我们需要进一步研究使用抗生素治疗幽门螺杆菌是否会减少胃癌患者死亡数量，或者是否能够阻止可以致癌的胃内膜细胞进一步恶化。
一项研究发现，在幽门螺杆菌治疗后使用质子泵抑制剂（PPI）的患者比未使用PPI的患者更容易得胃癌。还需要开展更多的研究以判定PPI是否会导致幽门螺杆菌治疗患者患胃癌。
下列因素是否会降低患胃癌的危险或对胃癌的危险没有影响尚且未知：
饮食
摄入新鲜果蔬量不足可能增加患胃癌的危险。一些研究表明食用富含维生素C和β-胡萝卜素的果蔬有助于降低患胃癌的危险。研究还表明全麦谷物、类胡萝卜素、绿茶以及大蒜中的某些成分可能降低患胃癌的危险。
研究表明摄入大量盐分可能增加患胃癌风险。现在许多美国人少吃盐以降低患高血压的危险。这可能就是美国胃癌发病率下降的原因。
膳食补充剂
摄入某些种类维生素、矿物质以及膳食补充剂是否有助于降低患胃癌几率尚不清楚。在中国的一项关于膳食中补充β-胡萝卜素、维生素E以及硒的研究表明，补充这些物质可减少胃癌的死亡人数。该项研究可能纳入了那些在日常饮食中没有上述营养素的人群。我们无法断定增加膳食补充剂是否会对饮食健康的人群产生相同的效果。
其他研究尚未证明服用膳食补充剂，如β-胡萝卜素、维生素C、维生素E或硒会降低患胃癌的危险。
癌症预防临床试验用于研究预防癌症的方法。
癌症预防临床试验是用于研究降低患某些类型癌症危险的方法。一些癌症预防临床试验对象为未患癌症，但是患癌风险增加的健康人群。还有一些癌症预防临床试验的对象为已经患有癌症，正在竭力避免患其他同类型癌症或者试图降低患新型癌症风险的人群。其他试验的对象为尚不知道有任何癌症危险因素的健康志愿者。
一些癌症预防临床试验旨在查明人们采取的措施是否可以预防癌症。这些措施可能包括摄食水果和蔬菜、锻炼、戒烟或服用某些药物、维生素、矿物质或者食品补充剂。
临床试验正在研究预防胃癌的新方法。
在NCI的临床试验搜索网页上可以找到有关NCI支持的临床试验的信息。 其他组织支持的临床试验可在ClinicalTrials.gov网站上找到。
Stomach Cancer Prevention
Avoiding risk factors and increasing protective factors may help prevent stomach cancer.
Avoiding cancer risk factors may help prevent certain cancers. Risk factors include smoking, being overweight, and not getting enough exercise. Increasing protective factors such as quitting smoking 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.
The following are risk factors for stomach cancer:
Certain medical conditions
Having any of the following medical conditions may increase the risk of stomach cancer:
Certain genetic conditions
Genetic conditions may increase the risk of stomach cancer in people with any of the following:
Diet
The risk of stomach cancer may be increased in people who:
Environmental causes
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.
The following are protective factors that may decrease the risk of stomach cancer:
Stopping smoking
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.
Treating Helicobacter pylori infection
Studies show that chronic infection 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.
One study found that patients who used proton pump inhibitors (PPIs) after treatment for H. pylori were more likely to get stomach cancer than those who did not use PPIs. More studies are needed to find out whether PPIs lead to cancer in patients treated for H. pylori.
It is not known if the following factors lower the risk of stomach cancer or have no effect on the risk of stomach cancer:
Diet
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.
Dietary supplements
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 prevention clinical trials are used to study ways to prevent cancer.
Cancer prevention clinical 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.
New ways to prevent stomach cancer are being studied in clinical trials.
Information about clinical trials supported by NCI can be found on NCI’s clinical trials search webpage. Clinical trials supported by other organizations can be found on the ClinicalTrials.gov website.
About This PDQ Summary
About PDQ
Physician Data Query (PDQ) is the National Cancer Institute's (NCI's) comprehensive cancer information database. The PDQ database contains summaries of the latest published information on cancer prevention, detection, genetics, treatment, supportive care, and complementary and alternative medicine. Most summaries come in two versions. The health professional versions have detailed information written in technical language. The patient versions are written in easy-to-understand, nontechnical language. Both versions have cancer information that is accurate and up to date and most versions are also available in Spanish.
PDQ is a service of the NCI. The NCI is part of the National Institutes of Health (NIH). NIH is the federal government’s center of biomedical research. The PDQ summaries are based on an independent review of the medical literature. They are not policy statements of the NCI or the NIH.
Purpose of This Summary
This PDQ cancer information summary has current information about stomach (gastric) cancer prevention. It is meant to inform and help patients, families, and caregivers. It does not give formal guidelines or recommendations for making decisions about health care.
Reviewers and Updates
Editorial Boards write the PDQ cancer information summaries and keep them up to date. These Boards are made up of experts in cancer treatment and other specialties related to cancer. The summaries are reviewed regularly and changes are made when there is new information. The date on each summary ("Updated") is the date of the most recent change.
The information in this patient summary was taken from the health professional version, which is reviewed regularly and updated as needed, by the PDQ Screening and Prevention Editorial Board.
Clinical Trial Information
A clinical trial is a study to answer a scientific question, such as whether one treatment is better than another. Trials are based on past studies and what has been learned in the laboratory. Each trial answers certain scientific questions in order to find new and better ways to help cancer patients. During treatment clinical trials, information is collected about the effects of a new treatment and how well it works. If a clinical trial shows that a new treatment is better than one currently being used, the new treatment may become "standard." Patients may want to think about taking part in a clinical trial. Some clinical trials are open only to patients who have not started treatment.
Clinical trials can be found online at NCI's website. For more information, call the Cancer Information Service (CIS), NCI's contact center, at 1-800-4-CANCER (1-800-422-6237).
Permission to Use This Summary
PDQ is a registered trademark. The content of PDQ documents can be used freely as text. It cannot be identified as an NCI PDQ cancer information summary unless the whole summary is shown and it is updated regularly. However, a user would be allowed to write a sentence such as “NCI’s PDQ cancer information summary about breast cancer prevention states the risks in the following way: [include excerpt from the summary].”
The best way to cite this PDQ summary is:
PDQ® Screening and Prevention Editorial Board. PDQ Stomach (Gastric) Cancer Prevention. Bethesda, MD: National Cancer Institute. Updated
Images in this summary are used with permission of the author(s), artist, and/or publisher for use in the PDQ summaries only. If you want to use an image from a PDQ summary and you are not using the whole summary, you must get permission from the owner. It cannot be given by the National Cancer Institute. Information about using the images in this summary, along with many other images related to cancer can be found in Visuals Online. Visuals Online is a collection of more than 3,000 scientific images.
Disclaimer
The information in these summaries should not be used to make decisions about insurance reimbursement. More information on insurance coverage is available on Cancer.gov on the Managing Cancer Care page.
Contact Us
More information about contacting us or receiving help with the Cancer.gov website can be found on our Contact Us for Help page. Questions can also be submitted to Cancer.gov through the website’s E-mail Us.
About This PDQ Summary
About PDQ
Physician Data Query (PDQ) is the National Cancer Institute's (NCI's) comprehensive cancer information database. The PDQ database contains summaries of the latest published information on cancer prevention, detection, genetics, treatment, supportive care, and complementary and alternative medicine. Most summaries come in two versions. The health professional versions have detailed information written in technical language. The patient versions are written in easy-to-understand, nontechnical language. Both versions have cancer information that is accurate and up to date and most versions are also available in Spanish.
PDQ is a service of the NCI. The NCI is part of the National Institutes of Health (NIH). NIH is the federal government’s center of biomedical research. The PDQ summaries are based on an independent review of the medical literature. They are not policy statements of the NCI or the NIH.
Purpose of This Summary
This PDQ cancer information summary has current information about stomach (gastric) cancer prevention. It is meant to inform and help patients, families, and caregivers. It does not give formal guidelines or recommendations for making decisions about health care.
Reviewers and Updates
Editorial Boards write the PDQ cancer information summaries and keep them up to date. These Boards are made up of experts in cancer treatment and other specialties related to cancer. The summaries are reviewed regularly and changes are made when there is new information. The date on each summary ("Updated") is the date of the most recent change.
The information in this patient summary was taken from the health professional version, which is reviewed regularly and updated as needed, by the PDQ Screening and Prevention Editorial Board.
Clinical Trial Information
A clinical trial is a study to answer a scientific question, such as whether one treatment is better than another. Trials are based on past studies and what has been learned in the laboratory. Each trial answers certain scientific questions in order to find new and better ways to help cancer patients. During treatment clinical trials, information is collected about the effects of a new treatment and how well it works. If a clinical trial shows that a new treatment is better than one currently being used, the new treatment may become "standard." Patients may want to think about taking part in a clinical trial. Some clinical trials are open only to patients who have not started treatment.
Clinical trials can be found online at NCI's website. For more information, call the Cancer Information Service (CIS), NCI's contact center, at 1-800-4-CANCER (1-800-422-6237).
Permission to Use This Summary
PDQ is a registered trademark. The content of PDQ documents can be used freely as text. It cannot be identified as an NCI PDQ cancer information summary unless the whole summary is shown and it is updated regularly. However, a user would be allowed to write a sentence such as “NCI’s PDQ cancer information summary about breast cancer prevention states the risks in the following way: [include excerpt from the summary].”
The best way to cite this PDQ summary is:
PDQ® Screening and Prevention Editorial Board. PDQ Stomach (Gastric) Cancer Prevention. Bethesda, MD: National Cancer Institute. Updated
Images in this summary are used with permission of the author(s), artist, and/or publisher for use in the PDQ summaries only. If you want to use an image from a PDQ summary and you are not using the whole summary, you must get permission from the owner. It cannot be given by the National Cancer Institute. Information about using the images in this summary, along with many other images related to cancer can be found in Visuals Online. Visuals Online is a collection of more than 3,000 scientific images.
Disclaimer
The information in these summaries should not be used to make decisions about insurance reimbursement. More information on insurance coverage is available on Cancer.gov on the Managing Cancer Care page.
Contact Us
More information about contacting us or receiving help with the Cancer.gov website can be found on our Contact Us for Help page. Questions can also be submitted to Cancer.gov through the website’s E-mail Us.