注：胃癌的预防、治疗以及癌症筛查和预防研究证据等级亦有单独的PDQ总结进行介绍。
基于一般证据，在美国等胃癌发病率相对较低的地区，采用X线钡餐荧光造影或血清胃蛋白酶原进行筛查并不会降低胃癌死亡率。
效应强度：不降低死亡率的一般证据。
效应强度：死亡率降低的证据不足。
基于确凿证据，筛查会导致少见但严重的内镜相关不良反应，可能包括穿孔、心肺事件、吸入性肺炎、以及需要住院治疗的出血事件。
效应强度：对于罕见但严重危害的确凿证据。
Note: Separate PDQ summaries on Stomach (Gastric) Cancer Prevention, Gastric Cancer Treatment, and Levels of Evidence for Cancer Screening and Prevention Studies are also available.
Based on fair evidence, screening with barium-meal photofluorography or serum pepsinogen would not result in a decrease in mortality from gastric cancer in areas with relatively low incidence of the disease, such as the United States.
Magnitude of Effect: Fair evidence for no reduction in mortality.
Magnitude of Effect: Inadequate evidence for mortality reduction.
Based on solid evidence, screening would result in uncommon but serious side effects associated with endoscopy, which may include perforation, cardiopulmonary events, aspiration pneumonia, and bleeding requiring hospitalization.
Magnitude of Effect: Solid evidence for rare but serious harms.
2020年，据估计美国将有27600人诊断为胃癌，11010人因胃癌死亡。
据估计，2015年中国胃癌新发病例40.3万例，死亡病例29.1万例。
被诊断为胃癌的患者约三分之二超过66岁。胃癌是世界范围内第四大常见肿瘤。胃癌在其他国家更加常见，主要包括日本、中欧、斯堪的纳维亚、中国香港地区、南美洲和中美洲国家、前苏联各国家、中国和韩国。胃癌是全球尤其是发展中国家的重要致死原因。
腺癌是胃癌的主要类型（95%）。胃恶性肿瘤还包括淋巴瘤、肉瘤、类癌及其它罕见类型。由于不同的胃癌类型在分期、治疗和预后上有明显差异，因此区别常见的腺癌与少见的淋巴瘤虽然有时比较困难，但很重要。
胃腺癌可进一步分为肠型和弥漫型。
肠型胃癌多为溃疡型病变，且较弥漫型更常发生于胃部远端。弥漫型胃癌比肠型的预后差。肠型胃癌常见于胃癌高发地区。全球胃癌发病率的降低在很大程度上要归因于肠型胃癌的减少。
自1930年以来，美国胃癌的发病率下降了4倍，每10万人中约有7例。
胃癌发病率急剧下降的原因尚不清楚，但可能与改善的食物储藏和饮食变化(如盐摄入量减少)有关。部分美国人的胃癌患病风险较高，包括患有萎缩性胃炎或恶性贫血的老年人、散发性胃腺瘤的患者、家族性腺瘤样息肉病的患者、或遗传性非息肉性结肠癌患者，及来自胃癌高发国家的其他种族移民。
胃癌的危险因素包括患有慢性萎缩性胃炎和肠上皮化生等癌前病变、恶性贫血和胃腺瘤性息肉。遗传和环境因素包括胃癌家族史；蔬菜水果摄入量低；盐腌、熏制或不良保存食品的摄入；吸烟。
证据一致性表明胃幽门螺杆菌的感染与胃体和胃窦癌及胃淋巴瘤的发生和进展高度相关。
国际癌症研究机构（IARC）将幽门螺杆菌感染列为非贲门胃癌和胃低度恶性B细胞粘膜相关淋巴样组织淋巴瘤的病因（即1类人类致癌物）。
与一般人群相比，十二指肠溃疡患者发生胃癌的风险较低。
X线钡餐荧光造影、胃镜和血清胃蛋白酶原等几种筛查技术已被提出作为早期检测胃癌的筛查方法。目前尚无评估筛查对胃癌死亡率影响的随机试验报道。
即使在极高风险地区，胃癌筛查的阳性预测值（PPV）也可能非常低。日本和歌山市一项胃镜筛查项目针对17647名40-60岁男性进行血清胃蛋白酶原联合X线钡餐造影筛查，研究时长七年，筛查的阳性预测值为0.85%。
血清胃蛋白酶原检测的阳性率为19.5%，造影检测阳性率为22.5%，肿瘤检出率为0.28%。七年期间，与年龄匹配的周边人群相比，胃癌死亡率未降低。
日本自20世纪60年代起即开展了一项基于人群的全国性胃癌钡餐荧光造影筛查项目。参与率达到了10%-20%之间。
虽然同期日本的胃癌死亡率确有下降，但全球多个即便无筛查项目发达国家的胃癌死亡率也在降低。日本的病例对照研究显示，接受筛查人群的胃癌死亡率有下降，但前瞻性研究的结果并不一致。
在哥斯达黎加开展了一项基于社区的X线荧光造影的初步研究，采用的手段与上述日本全国性项目相同（与日本专家商讨决定）。
人口注册中心通过信件邀请人们参加两轮筛查，共分析6200名合格的筛查参与者（计划招募12000人）。接受筛查后的2-7年间，其胃癌死亡率与未被邀请接受筛查的4组对照人群相比，相对危险度约为0.5（未报道P值）。然而，该研究存在较强偏倚，其中包括选择偏倚及可能倾向于排除既往曾被诊断为胃癌的人群，从而使结果有利于筛查组人群。除此之外，与社区对照不同，通过筛查项目诊断的胃癌患者均在同一转诊中心接受治疗。疑似荧光造影阳性的PPV为3%；两轮筛查的特异度分别为67%和80%；阳性率分别为34%和20%。尽管作者认为其研究结果为常规筛查可降低胃癌死亡率提供了有力证据，但也认为荧光造影技术的筛查成本对本国而言过高。
委内瑞拉1980年启动了一项采用放射荧光造影技术的筛查研究。通过病例对照研究评估该筛查项目对降低胃癌死亡率的作用，未检测到胃癌死亡率的降低。
胃镜对于胃癌检出的灵敏度优于荧光造影技术
一项针对亚洲胃癌内镜筛查研究的荟萃分析识别10项相关研究，均为非随机化研究。
这些研究于1989年至2014年期间在南韩、中国和日本开展。在这10项研究中，有6项研究将从未接受筛查者作为对照组，1项研究将接受X线筛查者作为对照组，还有3项研究将基于人群死亡率进行预测的死亡例数作为对照组。在一些研究中，镜筛查作为全国性筛查程序的一部分进行。该荟萃分析中，内镜筛查相关的胃癌死亡率合并风险比（RR）估值为0.60（95%置信区间[CI]，0.49-0.73），除1项研究外，其余所有研究报告的RR为0.72或更低。研究间存在显著异质性（P=0.001）,这是由于其中1项研究的RR高于1(1.01)；去掉该研究后，异质性无统计学意义（P=0.14）。4项巢式病例对照研究和6项队列研究的合并RR估计值分别为0.60（95% CI，0.47-0.76）和0.57（95% CI，0.39-0.83）。对照组为非筛查患者的6项研究合并风险比估值为0.58（95% CI，0.48-0.70）。
尚无研究评估胃血清蛋白酶原筛查对胃癌死亡率的影响，且其作为一种筛查技术在应用方面有重要局限性。血清胃蛋白酶原水平较低可能提示患有萎缩性胃炎，因此适用于对肠型胃癌的疑似癌前病变的检测，但并不适用于弥散型胃癌。
另外，血清胃蛋白酶原并无明确的诊断临界值。
最后，根除幽门螺杆菌和使用质子泵抑制剂治疗消化不良均会改变胃蛋白酶原水平，使得在这些干预措施广泛应用的情况下难以对结果进行解读。
日本的一项研究对5113例受试者进行血清胃蛋白酶原I和II(PGI和PGII)检测，并辅以胃镜筛查（检出13例胃癌），应用于鉴别胃癌的临界值为PGI低于70ng/mL及PGI/ PGII比值低于3。该两种筛查手段联合应用的灵敏度为84.6%，特异度为73.5%，阳性预测值为0.81%，阴性预测值为99.6%。
有证据支持可对一些高危美国人群进行胃癌筛查，但关于发病率达多高才值得筛查这一点仍存在争议。潜在风险较高的人群包括患有萎缩性胃炎或恶性贫血的老年患者、胃部分切除术后患者、
散发性胃腺瘤患者、
家族性腺瘤样息肉病患者、
或遗传性非息肉性结肠癌患者，
及来自胃癌高发国家的其他种族移民。
对胃癌常规筛查的伤害罕有量化或报道，证据主要来源于日本等胃癌极高危地区的筛查经验。
最常见的危害是出现假阳性结果。
暴露于低剂量的辐射（荧光造影中约为0.6mSv）理论上具有致癌风险，但风险缺乏量化。筛查的其他罕见并发症可能包括检测前用药（用于胃镜检查前，有时也用于荧光造影前）引起的不良反应，以及胃镜造成的出血或穿孔。
与任何筛查检测一样，胃癌的筛查可能造成过度诊断，并伴随过度治疗。由于穿孔和出血等伤害可能因筛查中心的经验而异，因此这些事件在低风险人群（如美国）中的发生风险可能高于日本的大规模筛查项目。
In 2020, it is estimated that 27,600 Americans will be diagnosed with gastric cancer and 11,010 will die of it.
Two-thirds of people diagnosed with gastric cancer are older than 66 years. Gastric cancer is the fourth most common cancer in the world. The disease is much more common in other countries, principally Japan, Central Europe, Scandinavia, Hong Kong, South and Central America, the Soviet Union, China, and Korea. Gastric cancer is a major cause of death worldwide, especially in developing countries.
The major type of gastric cancer is adenocarcinoma (95%). The remaining malignant tumors include lymphomas, sarcomas, carcinoid tumors and other rare types. Distinguishing the common adenocarcinoma from the uncommon lymphoma may sometimes be difficult but is important, due to major differences in staging, treatment, and prognosis.
Gastric adenocarcinomas can be further categorized into an intestinal type and a diffuse type.
Intestinal-type lesions are frequently ulcerative and occur in the distal stomach more often than the diffuse type. Diffuse-type lesions are associated with a worse prognosis than the intestinal type. The intestinal type tends to be predominant in geographic regions with a high incidence of gastric carcinoma. The decline in the incidence of gastric cancer worldwide is largely due to a decrease in the number of intestinal-type lesions.
The incidence of gastric cancer in the United States has decreased fourfold since 1930 to approximately seven cases per 100,000 people.
The reasons for this striking decrease in incidence are not fully understood but are suspected to be related to improved storage of food and changes in diet, such as decreased salt intake. Some populations of Americans are at elevated risk, including elderly patients with atrophic gastritis or pernicious anemia, patients with sporadic gastric adenomas, familial adenomatous polyposis, or hereditary nonpolyposis colon cancer, and immigrant ethnic populations from countries with high rates of gastric carcinoma.
Risk factors for gastric cancer include the presence of precursor conditions such as chronic atrophic gastritis and intestinal metaplasia, pernicious anemia, and gastric adenomatous polyps. Genetic and environmental factors include a family history of gastric cancer; low consumption of fruits and vegetables; consumption of salted, smoked, or poorly preserved foods; and cigarette smoking.
There is consistent evidence that Helicobacter pylori infection of the stomach is strongly associated with both the initiation and promotion of carcinoma of the gastric body and antrum, and of gastric lymphoma.
The International Agency for Research on Cancer (IARC) classifies H. pylori infection as a cause of noncardia gastric carcinoma and low-grade B-cell mucosa-associated lymphatic tissue gastric lymphoma (i.e., a Group 1 human carcinogen).
Compared with the general population, people with duodenal ulcer disease may have a lower risk of gastric cancer.
Several screening techniques, including barium-meal photofluorography, gastric endoscopy, and serum pepsinogen have been proposed as screening methods for the early detection of gastric cancer. No randomized trials evaluating the impact of screening on mortality from gastric cancer have been reported.
Even in very high-risk areas, the positive predictive value (PPV) of the screening tests may be very low. In a screening program of 17,647 men aged 40 to 60 years in Wakayama City, Japan, the PPV of combined serum pepsinogen and barium meal with digital radiography over the 7-year period was 0.85%.
The positive test rates were 19.5% for serum pepsinogen and 22.5% for radiography, with a cancer detection rate of 0.28%. Over the 7-year period, there was no reduction in gastric cancer mortality compared with an age-matched surrounding population.
A national program of population-based screening for gastric cancer using barium-meal photofluorography has been ongoing since the 1960s in Japan. Participation rates have been in the range of only 10% to 20%.
Although there has been a coincident decrease in mortality from gastric cancer in Japan, mortality rates have been decreasing in many developed countries despite the lack of screening programs. Case-control studies from Japan show decreases in gastric mortality in people who have undergone screening, but results from prospective studies were not consistent.
A pilot study of community-based photofluorography was conducted in Costa Rica using the same techniques as those used in Japan’s national program (with consultation from Japanese experts).
People were invited by letter from a population registry to attend two rounds of screening, and a total of 6,200 eligible screened participants (of a planned 12,000) were analyzed. Their gastric cancer mortality from 2 to 7 years after screening was compared with four control groups that had not been invited to be screened, and the relative risk was about 0.5 (no P value reported). The study was, however, prone to strong biases, including selection bias, and likely differential exclusion of people with previously diagnosed gastric cancer favoring the screened population. In addition, unlike the community controls, patients diagnosed with gastric cancer through the screening program were treated at a single referral center. The PPV of a suspicious fluorograph was 3%; the specificity in the two rounds was 67% and 80%; and the positivity rates were 34% and 20%. Despite the authors’ belief that their results provided substantial evidence that routine screening would decrease gastric cancer mortality, they concluded that the costs of screening with photofluorography would be far too high in their country.
A screening study was begun in Venezuela in 1980, using radiographic fluorography. The efficacy of this program in reducing mortality from stomach cancer was evaluated by means of a case-control study, and there was no detectable reduction in mortality from gastric cancer.
Endoscopy appears to be more sensitive than photofluorography for the detection of gastric cancer.
A meta-analysis of gastric cancer endoscopic screening studies in Asia identified ten relevant studies, all nonrandomized.
These studies were conducted during the period of 1989 to 2014 in South Korea, China, and Japan. Of the ten studies, a never-screened group was the comparator in six studies, a radiographic-screening group was the comparator in one study, and expected deaths based on population rates was the comparator in three studies. In some of the studies, the endoscopic screening was performed as part of a national screening program. The meta-analysis pooled risk ratio (RR) estimate of gastric cancer mortality associated with endoscopic screening was 0.60 (95% confidence interval [CI], 0.49–0.73), with all but one study showing an individual RR of 0.72 or lower. There was significant heterogeneity across studies (P = .001), which was because of the one study with an RR greater than one (1.01); removing that study resulted in no significant heterogeneity (P = .14). Pooled estimates for the four nested case-control studies and six cohort studies were 0.60 (95% CI, 0.47–0.76) and 0.57 (95% CI, 0.39–0.83), respectively. The pooled estimate for the six studies with the never-screened comparator group was 0.58 (95% CI, 0.48–0.70).
There are no studies evaluating the effect of screening with serum pepsinogen on gastric cancer mortality, and there are important limitations to its use as a screening test. Low serum pepsinogen levels indicate the presence of atrophic gastritis and are therefore applicable to the detection of presumed precursors for intestinal type gastric cancer rather than the diffuse type.
In addition, there are no standard cut-off values of abnormality.
Finally, eradication of H. pylori and use of proton pump inhibitors for the management of indigestion change pepsinogen levels, making interpretation of results difficult in the setting of widespread use of these interventions.
In Japan, measurement of serum pepsinogen levels I and II (PGI and PGII) in 5,113 subjects also screened by endoscopy (13 gastric cancers detected), used cut-off points for identifying risk for gastric cancer of less than 70 ng/mL for PGI and less than 3 ng/mL for the PGI:PGII ratio. This combination provided a sensitivity of 84.6%, a specificity of 73.5%, a PPV of 0.81%, and a negative predictive value of 99.6%.
There may be justification for screening some populations of Americans at higher risk, although there is considerable discussion about how much incidence would make the examination worthwhile. Potential subgroups might include elderly patients with atrophic gastritis or pernicious anemia, patients with partial gastrectomy,
patients with the diagnosis of sporadic adenomas,
familial adenomatous polyposis,
or hereditary nonpolyposis colon cancer,
and immigrant ethnic populations from countries with high rates of gastric carcinoma.
Harms of routine screening for gastric cancer are poorly quantitated or reported, and derive chiefly from screening experiences in very high-risk areas such as Japan.
The most frequent harm is the occurrence of false-positive tests.
Exposure to the low doses of radiation (about 0.6 mSv in photofluorography) carries a theoretical but poorly quantified risk of carcinogenesis. Additional rare complications of screening may include adverse effects of premedication (used for endoscopy and sometimes photofluorography), and bleeding or perforation from endoscopy.
As with any screening test, there is a possibility of overdiagnosis with attendant overtreatment. Since harms such as perforation and bleeding may vary with the experience of the screening center, they may be higher in populations at low risk for gastric cancer, such as the United States, than in mass screening programs in Japan.
对PDQ癌症信息总结进行定期审核，当有新可用信息时予以更新。本节介绍了截至上述日期对本总结所作的最新更新。
更新了2020年新发和死亡病例估计值的统计数据（引用美国癌症协会数据作为参考资料1）。
本总结由PDQ筛查和预防编辑委员会编写和维护，该编辑委员会独立于NCI单独编辑。本总结为独立的文献综述，不代表NCI或NIH的政策声明。关于总结政策和PDQ编辑委员会在维护PDQ总结中作用的更多信息，请参见‘关于本PDQ总结和PDQ®-NCI的综合性癌症数据库’页面。
The PDQ cancer information summaries are reviewed regularly and updated as new information becomes available. This section describes the latest changes made to this summary as of the date above.
Updated statistics with estimated new cases and deaths for 2020 (cited American Cancer Society as reference 1).
This summary is written and maintained by the PDQ Screening and Prevention Editorial Board, which is editorially independent of NCI. The summary reflects an independent review of the literature and does not represent a policy statement of NCI or NIH. More information about summary policies and the role of the PDQ Editorial Boards in maintaining the PDQ summaries can be found on the About This PDQ Summary and PDQ® - NCI's Comprehensive Cancer Database pages.
This PDQ cancer information summary for health professionals provides comprehensive, peer-reviewed, evidence-based information about stomach (gastric) cancer screening. It is intended as a resource to inform and assist clinicians who care for cancer patients. It does not provide formal guidelines or recommendations for making health care decisions.
This summary is reviewed regularly and updated as necessary by the PDQ Screening and Prevention Editorial Board, which is editorially independent of the National Cancer Institute (NCI). The summary reflects an independent review of the literature and does not represent a policy statement of NCI or the National Institutes of Health (NIH).
Board members review recently published articles each month to determine whether an article should:
Changes to the summaries are made through a consensus process in which Board members evaluate the strength of the evidence in the published articles and determine how the article should be included in the summary.
Any comments or questions about the summary content should be submitted to Cancer.gov through the NCI website's Email Us. Do not contact the individual Board Members with questions or comments about the summaries. Board members will not respond to individual inquiries.
Some of the reference citations in this summary are accompanied by a level-of-evidence designation. These designations are intended to help readers assess the strength of the evidence supporting the use of specific interventions or approaches. The PDQ Screening and Prevention Editorial Board uses a formal evidence ranking system in developing its level-of-evidence designations.
PDQ is a registered trademark. Although the content of PDQ documents can be used freely as text, it cannot be identified as an NCI PDQ cancer information summary unless it is presented in its entirety and is regularly updated. However, an author would be permitted to write a sentence such as “NCI’s PDQ cancer information summary about breast cancer prevention states the risks succinctly: [include excerpt from the summary].”
The preferred citation for this PDQ summary is:
PDQ® Screening and Prevention Editorial Board. PDQ Stomach (Gastric) Cancer Screening. Bethesda, MD: National Cancer Institute. Updated
Images in this summary are used with permission of the author(s), artist, and/or publisher for use within the PDQ summaries only. Permission to use images outside the context of PDQ information must be obtained from the owner(s) and cannot be granted by the National Cancer Institute. Information about using the illustrations in this summary, along with many other cancer-related images, is available in Visuals Online, a collection of over 2,000 scientific images.
The information in these summaries should not be used as a basis for insurance reimbursement determinations. More information on insurance coverage is available on Cancer.gov on the Managing Cancer Care page.
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 Email Us.
This PDQ cancer information summary for health professionals provides comprehensive, peer-reviewed, evidence-based information about stomach (gastric) cancer screening. It is intended as a resource to inform and assist clinicians who care for cancer patients. It does not provide formal guidelines or recommendations for making health care decisions.
This summary is reviewed regularly and updated as necessary by the PDQ Screening and Prevention Editorial Board, which is editorially independent of the National Cancer Institute (NCI). The summary reflects an independent review of the literature and does not represent a policy statement of NCI or the National Institutes of Health (NIH).
Board members review recently published articles each month to determine whether an article should:
Changes to the summaries are made through a consensus process in which Board members evaluate the strength of the evidence in the published articles and determine how the article should be included in the summary.
Any comments or questions about the summary content should be submitted to Cancer.gov through the NCI website's Email Us. Do not contact the individual Board Members with questions or comments about the summaries. Board members will not respond to individual inquiries.
Some of the reference citations in this summary are accompanied by a level-of-evidence designation. These designations are intended to help readers assess the strength of the evidence supporting the use of specific interventions or approaches. The PDQ Screening and Prevention Editorial Board uses a formal evidence ranking system in developing its level-of-evidence designations.
PDQ is a registered trademark. Although the content of PDQ documents can be used freely as text, it cannot be identified as an NCI PDQ cancer information summary unless it is presented in its entirety and is regularly updated. However, an author would be permitted to write a sentence such as “NCI’s PDQ cancer information summary about breast cancer prevention states the risks succinctly: [include excerpt from the summary].”
The preferred citation for this PDQ summary is:
PDQ® Screening and Prevention Editorial Board. PDQ Stomach (Gastric) Cancer Screening. Bethesda, MD: National Cancer Institute. Updated
Images in this summary are used with permission of the author(s), artist, and/or publisher for use within the PDQ summaries only. Permission to use images outside the context of PDQ information must be obtained from the owner(s) and cannot be granted by the National Cancer Institute. Information about using the illustrations in this summary, along with many other cancer-related images, is available in Visuals Online, a collection of over 2,000 scientific images.
The information in these summaries should not be used as a basis for insurance reimbursement determinations. More information on insurance coverage is available on Cancer.gov on the Managing Cancer Care page.
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 Email Us.