什么是预防？
癌症预防就是采取措施以降低患癌几率。通过癌症预防，降低人群癌症新发病例，进而降低癌症死亡病例数。
为预防癌症新发，科学家们着眼于发现癌症危险因素和保护性因素。任何增加患癌几率的因素都被称为癌症危险因素；任何降低患癌几率的因素都被称为癌症保护性因素。
一些癌症危险因素是可以被改变的，但一些无法避免。例如，吸烟和遗传是某些癌症的危险因素，但只有吸烟是可以被改变的。定期锻炼和健康饮食也许是某些癌症的保护性因素。避免危险因素和增加保护性因素可能会降低患癌风险，但这并不意味着你就不会得癌症。
正在研究的预防癌症的方式有：
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:
关于肝（肝细胞）癌的基本信息
肝癌是肝脏组织细胞恶变引发的疾病。
肝脏是人体最大的器官之一。它有两个肝叶，位于右季肋部及上腹部。肝脏的三个重要功能是：
肝脏的解剖图。肝脏位于上腹部，靠近胃、肠、胆囊和胰腺。肝脏分右叶和左叶。每个肝叶被分为两个部分（未显示）。
有关肝癌的更多信息，请参阅以下的PDQ总结：
肝癌在美国并不常见，但在世界其他地方却很常见。
肝癌是男性第五大常见癌症，女性第九大常见癌症，居全球癌症死亡谱第二位。它在非洲撒哈拉以南地区及东亚地区高发。在美国，男性，尤其是亚裔/太平洋岛居民、美国印第安人/阿拉斯加原住居民和西班牙裔男性，罹患肝癌风险更高。肝癌新发病例持续增加，使其成为美国第五大癌症致死原因。
在中国，肝癌位居男性癌症发病谱第三位，死亡谱第二位；在女性中肝癌居发病谱第七位，死亡谱第三位。男性发病和死亡高于女性，农村高于城市。
早期发现并治疗肝癌可预防肝癌死亡。
感染某些类型的肝炎病毒可导致肝炎，并可能导致肝癌。
肝炎最常见的病因是肝炎病毒感染。肝炎可引起肝脏炎症（肿胀）。肝炎对肝脏的长期慢性损害会增加肝癌风险。
乙肝（HBV）病毒和丙肝（HCV）病毒是肝炎病毒的两种类型。慢性乙肝或丙肝病毒感染可增加肝癌发生风险。
乙型肝炎
乙型肝炎病毒是由接触乙肝病毒感染者的血液、精液或其他体液感染的。这种感染可以通过分娩从母亲传给孩子，还会通过性接触或共用注射药物的针头传染。它会引起肝硬化，进而导致肝癌。
丙型肝炎
丙型肝炎是由接触丙肝病毒感染者的血液导致的。这种感染可以通过共用注射药物的针头传播，也可以通过性接触传播。在过去，它还可以通过输血或器官移植传播。今天，血库对所有捐献的血液进行丙型肝炎病毒检测，这大大降低了通过输血感染病毒的风险。它会导致肝脏瘢痕（肝硬化），从而导致肝癌。
General Information About Liver (Hepatocellular) Cancer
Liver cancer is a disease in which malignant (cancer) cells form in the tissues of the liver.
The liver is one of the largest organs in the body. It has two lobes and fills the upper right side of the abdomen inside the rib cage. Three of the many important functions of the liver are:
Anatomy of the liver. The liver is in the upper abdomen near the stomach, intestines, gallbladder, and pancreas. The liver has a right lobe and a left lobe. Each lobe is divided into two sections (not shown).
See the following PDQ summaries for more information about liver (hepatocellular) cancer:
Liver cancer is not common in the United States, but it is common in other parts of the world.
Liver cancer is the fifth most common cancer in men, the ninth most common cancer in women, and the second leading cause of cancer death in the world. It is most common in sub-Saharan Africa and parts of eastern Asia, including China, Hong Kong, and Taiwan. In the United States, men, especially Asian/Pacific Islander, American Indian/Alaska Native, and Hispanic men, have an increased risk of liver cancer. The number of new cases of liver cancer continues to increase, making it the fifth leading cause of cancer deaths in the United States.
Finding and treating liver cancer early may prevent death from liver cancer.
Being infected with certain types of the hepatitis virus can cause hepatitis and may lead to liver cancer.
Hepatitis is most commonly caused by the hepatitis virus. Hepatitis is a disease that causes inflammation (swelling) of the liver. Damage to the liver from hepatitis that lasts a long time can increase the risk of liver cancer.
Hepatitis B (HBV) and hepatitis C (HCV) are two types of the hepatitis virus. Chronic infection with HBV or HCV can increase the risk of liver cancer.
Hepatitis B
HBV is caused by contact with the blood, semen, or other body fluid of a person infected with HBV virus. The infection can be passed from mother to child during childbirth, through sexual contact, or by sharing needles that are used to inject drugs. It can cause scarring of the liver (cirrhosis) that may lead to liver cancer.
Hepatitis C
HCV is caused by contact with the blood of a person infected with HCV virus. The infection can be spread by sharing needles that are used to inject drugs or, less often, through sexual contact. In the past, it was also spread during blood transfusions or organ transplants. Today, blood banks test all donated blood for HCV, which greatly lowers the risk of getting the virus from blood transfusions. It can cause scarring of the liver (cirrhosis) that may lead to liver cancer.
肝癌预防
避免危险因素并增加保护因素有助于预防癌症发生
避免癌症危险因素（如吸烟、超重、缺乏锻炼）可有助于预防某些癌症发生，增加保护因素（如戒烟和体育锻炼），可预防某些癌症的发生。咨询医生或其他专业人员，该如何降低患癌风险。
慢性乙型肝炎和丙型肝炎是肝癌的危险因素，乙型肝炎慢性感染是中国主要的肝癌诱因。
慢性乙型肝炎或慢性丙型肝炎会增加罹患肝癌的风险。同时感染乙肝病毒（HBV）和丙肝病毒（HCV）、合并其他危险因素者，患肝癌风险更高。感染HBV或HCV的男性较女性更易患肝癌。
慢性乙肝病毒感染是亚洲和非洲人群肝癌的主要病因。慢性丙肝病毒感染是北美、欧洲和日本人群肝癌的主要病因。
以下是其他肝癌危险因素
肝硬化
肝硬化患者发生肝癌的风险增加，肝硬化是一种健康的肝组织被疤痕组织替代的疾病。疤痕组织阻碍了肝脏血液流动，使肝脏无法正常工作。慢性酒精中毒和慢性肝炎是肝硬化的常见原因。与乙肝和饮酒相关的肝硬化患者相比，丙肝相关的肝硬化患者罹患肝癌的风险更高。
重度饮酒
重度饮酒会导致肝硬化，肝硬化是肝癌的危险因素之一。没有肝硬化的过度饮酒者也会发生肝癌。患有肝硬化的过度饮酒者患肝癌的可能性是无肝硬化的过度饮酒者的十倍。
研究表明，重度饮酒的乙肝病毒或丙肝病毒感染者罹患肝癌的风险也会增加。
黄曲霉毒素B1
食用含有黄曲霉毒素B1的食物会增加肝癌发生风险（黄曲霉毒素B1是一种真菌产生的毒素，这种真菌可以在食物上生长，比如储存在炎热、潮湿地方的玉米和坚果）。它在非洲撒哈拉以南地区、东南亚和中国最为常见。
非酒精性脂肪性肝炎（NASH）
非酒精性脂肪性肝炎（NASH）是一种可能导致肝硬化的疾病，而肝硬化可导致肝癌。非酒精性脂肪性肝炎是最严重的一种非酒精性脂肪性肝病（NAFLD），肝脏中脂肪含量异常。对一些人来说，这会导致炎症和肝细胞损伤。
非酒精性脂肪性肝炎相关的肝硬化可增加肝癌发病风险。在没有肝硬化的非酒精性脂肪性肝炎（NASH）患者中也发现了肝癌。
吸烟
吸烟会增加肝癌发生风险，且吸烟量越大，吸烟年限越长，发生肝癌风险越高。
其他疾病
某些罕见的疾病和遗传病也会增加肝癌的风险。这些疾病包括：
以下保护性因素可以降低患肝癌的风险：
乙型肝炎疫苗
预防乙肝病毒感染（在新生儿时接种乙肝疫苗）已被证明可以降低儿童的肝癌发病风险。目前还不知道接种疫苗是否能够降低成年人罹患肝癌的风险。
治疗慢性乙型肝炎病毒感染
慢性乙肝病毒感染者的治疗方案包括干扰素和核苷(酸)类似物(NA)治疗。这些治疗方法可降低罹患肝癌的风险。
减少黄曲霉毒素B1暴露
避免食用黄曲霉毒素B1含量高的食物，选择不含黄曲霉毒素B1的食物，可以降低患肝癌风险。
预防癌症的临床试验用于研究如何预防癌症。
癌症预防临床试验用于研究如何降低某些癌症发病风险。一些癌症预防临床试验在健康人群或高风险人群中进行。一些癌症预防临床试验在已患癌人群中进行，以预防同类型癌症复发或是降低患新癌症的可能性。一些试验是在健康志愿者中进行的，这些这些志愿者是否具有癌症发生危险因素并不清楚。
癌症预防临床试验的目的是证实人们采取的措施是否能预防癌症。这可能包括摄入水果和蔬菜、锻炼、戒烟或服用某些药物、维生素、矿物质或食品添加剂。
正在开展临床试验研究的预防肝癌新方式。
有关NCI支持的临床试验信息可在NCI临床试验搜索网页上找到。其他组织支持的临床试验可在ClinicalTrials.gov网站上找到相关信息。
Liver (Hepatocellular) Cancer Prevention
Avoiding risk factors and increasing protective factors may help prevent 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.
Chronic Hepatitis B and C infections are risk factors that may lead to liver cancer.
Having chronic hepatitis B (HBV) or chronic hepatitis C (HCV) increases the risk of developing liver cancer. The risk is even higher for people with both HBV and HCV, and for people who have other risk factors in addition to the hepatitis virus. Men with chronic HBV or HCV infection are more likely to develop liver cancer than are women with the same chronic infection.
Chronic HBV infection is the leading cause of liver cancer in Asia and Africa. Chronic HCV infection is the leading cause of liver cancer in North America, Europe, and Japan.
The following are other risk factors that may increase the risk of liver cancer:
Cirrhosis
The risk of developing liver cancer is increased for people who have cirrhosis, a disease in which healthy liver tissue is replaced by scar tissue. The scar tissue blocks the flow of blood through the liver and keeps it from working as it should. Chronic alcoholism and chronic hepatitis infections are common causes of cirrhosis. People with HCV-related cirrhosis have a higher risk of developing liver cancer than people with cirrhosis related to HBV or alcohol use.
Heavy alcohol use
Heavy alcohol use can cause cirrhosis, which is a risk factor for liver cancer. Liver cancer can also occur in heavy alcohol users who do not have cirrhosis. Heavy alcohol users who have cirrhosis are ten times more likely to develop liver cancer, compared with heavy alcohol users who do not have cirrhosis.
Studies have shown there is also an increased risk of liver cancer in people with HBV or HCV infection who use alcohol heavily.
Aflatoxin B1
The risk of developing liver cancer may be increased by eating foods that contain aflatoxin B1 (poison from a fungus that can grow on foods, such as corn and nuts, that have been stored in hot, humid places). It is most common in sub-Saharan Africa, Southeast Asia, and China.
Nonalcoholic steatohepatitis (NASH)
Nonalcoholic steatohepatitis (NASH) is a condition that can cause scarring of the liver (cirrhosis) that may lead to liver cancer. It is the most severe form of nonalcoholic fatty liver disease (NAFLD), where there is an abnormal amount of fat in the liver. In some people, this can cause inflammation (swelling) and injury to the cells of the liver.
Having NASH-related cirrhosis increases the risk of developing liver cancer. Liver cancer has also been found in people with NASH who do not have cirrhosis.
Cigarette smoking
Cigarette smoking has been linked to a higher risk of liver cancer. The risk increases with the number of cigarettes smoked per day and the number of years the person has smoked.
Other conditions
Certain rare medical and genetic conditions may increase the risk of liver cancer. These conditions include the following:
The following protective factors may decrease the risk of liver cancer:
Hepatitis B vaccine
Preventing HBV infection (by being vaccinated for HBV as a newborn) has been shown to lower the risk of liver cancer in children. It is not yet known if being vaccinated lowers the risk of liver cancer in adults.
Treatment for chronic hepatitis B infection
Treatment options for people with chronic HBV infection include interferon and nucleos(t)ide analog (NA) therapy. These treatments may reduce the risk of developing liver cancer.
Reduced exposure to aflatoxin B1
Replacing foods that contain high amounts of aflatoxin B1 with foods that contain a much lower level of the poison can reduce the risk of liver 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 developing certain types of cancer. Some cancer prevention trials are conducted with healthy people who have not had cancer but who have an increased risk for cancer. Other prevention trials are conducted 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 liver 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 liver (hepatocellular) 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 Liver (Hepatocellular) 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 liver (hepatocellular) 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 Liver (Hepatocellular) 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.