中国人群胃癌发病影响因素的Meta分析

目的:运用Meta分析的方法探讨中国人群胃癌发病的影响因素,为我国胃癌的预防控制提供参考依据。方法:计算机检索PubMed、Embase、Cochrane Library、Web of Science、中国生物医学文献数据库（CBM）、中国学术期刊全文数据库（CNKI）、万方数据库（WANFANG）及维普数据库（VIP）,收集2000年1月至2020年12月公开发表的关于中国人群胃癌发病影响因素的相关文献,并利用Stata16.0软件对纳入的文献进行分析。结果:共纳入45篇文献,均为病例对照研究,累计病例10 643例,对照14 073例。各影响因素的合并OR值及95%CI如下:吸烟（2.34,2.04~2.67）、慢性胃病史（4.40,3.68~5.24）、肿瘤家族史（2.98,2.49~3.56）、常吃蔬菜（0.29,0.24~0.36）、不良情绪（1.85,1.62~2.11）、常吃腌制食品（3.09,2.58~3.71）、进食不规律（3.06,2.32~4.05）、常吃烫食（1.87,1.61~2.16）、常饮茶（0.38,0.32~0.45）、常饮（1.76,1.51~2.05）、高盐饮食（2.53,2.14~2.99）、常吃葱姜蒜（0.56,0.48~ 0.65）、幽门螺杆菌感染（3.30,2.67~4.10）、常吃水果（0.49,0.40~0.60）、进食速度快（3.36,2.83~3.99）、常吃烤制食品（2.64,2.02~3.44）、常吃豆类食品（0.66,0.56~0.78）、常吃油炸食品（2.82,1.94~4.09）、常吃干硬食物（1.98,1.40~2.78）、常吃霉变食品（4.94,3.24~7.54）。结论:吸烟、慢性胃病史、肿瘤家族史、不良情绪、常吃腌制食品、进食不规律、常吃烫食、常饮酒、高盐饮食、幽门螺杆菌感染、进食速度快、常吃烤制食品、常吃油炸食品、常吃干硬食物、常吃霉变食品为中国人群胃癌发病的危险因素。常吃蔬菜、常饮茶、常吃葱姜蒜、常吃水果、常吃豆类食品为胃癌发病的保护因素。     

生活习惯和饮食与胃癌发生的相关性研究

目的:探讨生活习惯和饮食等危险因素与胃癌发生的关系。方法:采用病例对照研究,胃癌患者97例,非胃癌肿瘤患者77例为对照组,调查患者的一般情况、既往史及家族史、饮食摄入情况、生活居住环境以及饮酒和吸烟史等,饮食部分的调查采用频数法。对资料进行单因素和多因素非条件Logistic回归分析。结果:单因素分析结果,饮酒、吸烟年限长、有胃癌家族史和喜吃腌制食物是胃癌的危险因素,OR值分别为2.456、2.333、3.060和1.959;清淡、酸性食物、喝绿茶和喝茶年限超过20年是胃癌的保护性因素,OR值分别为0.402、0.297、0.402和0.331;多因素分析结果,腌制食物、吸烟年限长、胃癌家族史是胃癌的危险因素,而清淡饮食和喝茶年限长是胃癌的保护性因素。结论:腌制食物、吸烟年限长和胃癌家族史可增加胃癌的发病风险,而清淡饮食和喝茶年限长可降低胃癌发生的危险性。     

食管-胃交界腺癌地域发病特点与思考

我国食管癌高发区主要分布在华北太行山、陕豫秦岭、鄂豫皖大别山、川北、闽粤、苏北为主的六大地理区域.同时西北部的新疆、甘肃也存在着食管癌的高发区域.2000年WHO将贲门癌称为:食管-胃交界腺癌.近年来高发区流行病学调查看到贲门癌发病迅速上升.本文从地域角度分析发病死亡登记资料和临床诊断数据,以期了解贲门癌发病趋势和原因.在华北太行山脉,川北和苏北三个地域.10个食管癌高发区中有六个地区男性胃癌的发病为第一位的,在闽粤、陕豫秦岭、西北部地域也有同样的流行趋势.甘肃西北部以1977～1988年和1989～2000年两个时间段的内镜诊断做了比较,贲门胃底癌检出率上升了29.9%,其中武威市贲门癌占胃癌的45.8%.分析新疆维吾尔族胃癌的发病部位,贲门癌占43.9%～45.3%.根据目前地域流行病学资料,我国传统食管癌高发区普遍还存在着贲门癌的高发.这种现象在山区,交通闭塞区域更为突出.分析高发的原因主要有两个:一是根据ICD-8编码要求,贲门癌归入胃癌统计,改变了我国传统将贲门癌归入食管癌的登记方法,二是内镜广泛的应用,提高了食管癌和贲门癌的鉴别诊断.未来的病因研究单纯从吸烟饮酒思维模式似不能完全解释.地域性贲门癌的发病与遗传因素有更密切的关系.     

生活习惯和饮食与胃癌发生的相关性研究

目的：探讨生活习惯和饮食等危险因素与胃癌发生的关系。方法：采用病例对照研究，胃癌患者97例，非胃癌肿瘤患者77例为对照组，调查患者的一般情况、既往史及家族史、饮食摄入情况、生活居住环境以及饮酒和吸烟史等，饮食部分的调查采用频数法。对资料进行单因素和多因素非条件Logistic回归分析。结果：单因素分析结果，饮酒、吸烟年限长、有胃癌家族史和喜吃腌制食物是胃癌的危险因素，OR值分别为2．456、2．333、3．060和1．959；清淡、酸性食物、喝绿茶和喝茶年限超过20年是胃癌的保护性因素，OR值分别为0．402、0．297、0．402和0．331；多因素分析结果，腌制食物、吸烟年限长、胃癌家族史是胃癌的危险因素，而清淡饮食和喝茶年限长是胃癌的保护性因素。结论：腌制食物、吸烟年限长和胃癌家族史可增加胃癌的发病风险，而清淡饮食和喝茶年限长可降低胃癌发生的危险性。     

上海市区胃癌危险因素探讨

目的 探索上海市区胃癌的危险因素，为采取有效的预防措施提供科学依据。方法 采用全人群病例对照研究，共调查1999年4月～1999年10月期间诊断的30～74岁的上海市区新发胃癌病例311例(男性198例，女性113例)，对照1579例，获得环境暴露等资料。采用非条件logistic模型控制混杂因素计算各个因素的调整比值比(OR)和95％可信限(95％CI)。结果 男性中吸烟、热烫饮食、油炸面食、患病前精神压抑和自我调节能力差、慢性胃炎及一级亲属胃癌史等因素可增加患胃癌的危险性；女性胃癌则与腌制食品(尤其是腌制蔬菜)、油炸食品、酒精摄人、患病前精神压抑和自我调节能力差、溃疡病史、慢性胃炎史及一级亲属胃癌史等关系密切。新鲜蔬菜、水果，新鲜豆类，豆制品，植物油和蛋及蛋制品等对胃癌有保护作用。调整可能的混杂因素后，分析结果均达到显著水平。结论 上海市区胃癌近十年危险因素没有明显改变，吸烟、腌制食品和油炸食品、慢性胃炎史和胃癌家族史等可能是主要的危险因素，而多食新鲜蔬菜和水果、豆及豆制品等对胃癌有保护作用。     

如皋市饮食因素与食管鳞癌关系的病例对照研究

[目的]探讨如皋市饮食因素与食管癌发病的关系.[方法]用1:1配对病例对照研究的方法筛选食管鳞癌的饮食危险因素,食管癌病例和对照各100例.[结果]单因素分析结果显示经常吃饭时生气、常吃咸鱼咸肉、常吃腌菜、常吃豆酱、三餐不定时、常进过烫食物、进食过快、饮酒8个因素与食管癌发病有关.条件Logistic多因素回归分析显示4个危险因素,经常吃饭时生气(OR=6.88,95%CI1.21～39.05)、常吃咸鱼咸肉(9.06,1.26～65.31)、常吃腌菜(4.72,1.95～11.46)、进食过快(4.38,1.78～10.77).[结论]不健康的饮食习惯是食管癌发病的危险因素,经常吃饭时生气、常吃咸鱼咸肉、常吃腌菜、进食过快等是食管癌的独立危险因素.     

食管癌发病影响因素Meta分析

[目的]定量综合评价各种危险因素在食管癌发病中的作用.[方法]从<中国生物医学文献数据库(1994～2003)>和<中国期刊网>上,搜集研究食管癌危险因素的文献,利用随机模型进行Meta分析.[结果]检索到符合纳入标准的文章12篇.病例组2161人,对照组3813人.Meta分析结果显示:有食管癌家族史的人患食管癌比值比(ORDL)为2.45(1.66～3.62);食用腌制食品ORDL为1.87(1.55～2.26);吸烟ORDL为1.43(1.09～1.87);饮酒ORDL为2.16(1.55～2.99);喜欢吃烫食ORDL为2.41(1.95～2.98);经常食用蔬菜和水果是保护性因素,OR.为0.52(0.40～0.67).[结论]食管癌家族史、吃腌制食品、吸烟、饮酒、喜欢吃烫食均增加患食管癌的危险性,吃蔬菜和水果是保护性因素.     

上海市居民饮食与胃癌关系的病例对照研究

目的：探讨上海市居民饮食与胃癌发生的关系。方法：采用全人群病例对照研究，调查1999年4月－10月间诊断的上海市区新发胃癌病例311例（男性198例，女性113例），对照1579例（为“九五”课题中乳腺癌，肺癌及胃癌病例－对照研究之一，对照共用）。采用非条件logistic回归分析，调整可能的混杂因素，包括年龄，文化程度，吸烟（仅男性）慢性胃炎及一级亲属胃癌家族史等，分析饮食口味，热烫饮食，新鲜蔬菜和水果，豆及豆制品，蛋及蛋制品，家禽类，腌制食品，油炸食品，植物油等饮食因素，以估计胃癌发生的比数比和95％可信区间。结果：研究发现新鲜蔬菜（最高摄入量OR＝0．6），水果（OR＝0．6），新鲜豆类OR＝0．4），豆制品（OR＝0．4）和植物油（OR＝0．6）是男性胃癌的保护因素，而油面食（OR＝1．6）增加男性胃癌的危险性，新鲜蔬菜9OR＝0．3），水果（OR＝0．4），新鲜豆类（OR＝0．4，干豆类（OR＝0．5）和蛋及蛋制品（OR＝0．5）对妇性胃癌具有保护作用，而腌制食品（OR＝2．2）和油食品（包括油鱼／肉、油炸面食，油煎蛋和油煎花生米，OR＝2．6是女性胃癌主要的危险因素，重盐饮食和热烫饮食及早餐不规律增加胃癌发生的危险，未发现主食，新鲜肉类（包括鱼，家禽类，红肉类）等与胃癌妇生有联系，结论：高盐饮食，热烫饮食，腌制食品和油炸食品是上海市胃癌的重要危险因素，而新鲜蔬菜，水果，豆及豆制品和植物油等可降低胃癌的危险性。     

非吸烟人群肺癌危险因素的病例对照研究

目的探讨中国非吸烟人群肺癌的危险因素,为防癌措施提供依据。方法采用病例对照研究的方法,按频数匹配收集非吸烟肺癌新发病例306例及非吸烟对照306例,利用统一编制的调查表对调查对象进行面访,收集病例和对照危险因素的暴露史等。结果单因素分析发现25个因素与非吸烟人群肺癌的发病有关联;多因素分析后发现：非吸烟人群肺癌发病的危险因素是体重指数(body mass index,BMI)＜18.5,居住地周围有污染企业、装修刺激性气味、家庭被动吸烟、工作场所被动吸烟、使用农药、性格内向、食用油炸食品、肺部手术史、癌症家族史,而保护因素是BMI≥24、常吃蛋类、常吃水果、饮茶、常以散步作为锻炼(2年前),经广义多因子降维法（GWDR）拟合的最优的交互作用模型是居住地企业+装修刺激性气味+家庭被动吸烟+工作场所被动吸烟+农药接触史+癌症家族史。结论非吸烟者发生肺癌的影响因素较多,仍需进一步识别。     

福建省贲门癌发病因素的病例对照研究

 目的　探讨贲门癌发生的危险因素。方法采用病例对照研究方法 ,研究对象 5 82例 ,其中贲门癌新病例 2 91例 ,对照 2 91例。应用统一制订的调查表进行流行病学调查。对资料进行单因素和多因素Logistic回归分析。 结果　贲门癌的危险因素有 :三餐不按时 (OR =1.4 4,95 %CI :1.15 1.81)、进食快 (OR=1.4 0 ,95 %CI :1.0 9 1.80 )、食用猪油 (OR =1.6 7,95 %CI :1.19 2 .35 )、饮用井水 (OR =1.90 ,95 %CI :1.2 7 2 .84 )、吸烟 (OR =1.2 8,95 %CI :1.0 5 1.5 8)和家庭肿瘤史 (OR =3.15 ,95 %CI :1.97 5 .0 4 )。常吃新鲜蔬菜(OR =0 .5 3,95 %CI :0 .2 8 0 .99)、水果 (OR =0 .75 ,95 %CI :0 .5 6 1.0 0 )、牛奶 (OR =0 .5 2 ,95 %CI :0 .2 9 0 .93)及文化程度高者 ,其胃癌发生风险低。结论　本研究首次发现不良的饮食方式是贲门癌的危险因素 ,对...     

Population-based Case-control Study on Risk Factors for Esophageal Cancer in Five High-risk Areas in China

Objective: To study major etiological factors for esophageal cancer in upper gastrointestinal cancer high riskareas in China. Methods: Five areas with high incidences of esophageal and gastric cancer with good qualitycancer registration data were selected for the study: Cixian, Shexian from Hebei Province, Linxian from HenanProvince, Feicheng from Shandong Province and Zhuanghe from Liaoning Province. A total of 250 cases wererandomly recruited from the cancer registration database diagnosed as arising in the lower esophageal segmentsince January 1, 2009. Three controls were identified and matched with each case as having similar characteristics,such as gender, sex and residency. Questionnaires were applied by face to face interview with trained staff, anddata entry was conducted using EPIDATA software. Conditional logistic models were employed for univariateand multivariate analyses to evaluate odd ratios and 95% confident intervals, with SPSS 13.0 statistic software.Results: In single variable analysis, gastrointestinal history, GERD, smoking, passive smoking, alcohol drinking,hot food, pickled food, overnight vegetable, dried food, no breakfast, false dining posture were found to be riskfactors of esophageal cancer. Eating more fresh vegetables and high BMI were protective factors. Gastrointestinalhistory (OR=12.658), not taking regular meals (3.465), overnight vegetables (OR=3.296), GERD (OR=3.044),hot food (OR=2.510), passive smoking (OR=2.423), pickled food (OR=2.273), alcohol drinking (OR=2.074),seldom eating breakfast(OR=1.987), and false dining posture (OR=1.977) increased the risk of esophageal canceron multivariate logistic analysis, and fresh vegetables (OR=0.279) and BMI≥25 (OR=0.528) continued to beprotective. Conclusions: Esophageal cancer could be caused by genetics acting in synergy with environmentalfactors. Health education for the general population in high risk areas should be strengthened, with interventionprograms of nutrition and lifestyle focusing on effective prevention and control for upper gastrointestinal cancer.     

江苏省肿瘤低发区主要恶性肿瘤危险因素配对病例对照研究

[目的]探讨江苏省恶性肿瘤低发地区主要肿瘤有关危险因素。[方法]在江苏省恶性肿瘤低发的赣榆地区进行了以人群为基础的肿瘤1：1配对病例对照研究,应用条件Logisfic回归对相关因素进行单因素和多因素分析。[结果]食管癌和胃癌的共同危险因素为进食快（OR食管=1.95，OR胃=1.46）、热烫饮食（OR食管=2.72，OR胃=2.21）、癌症家族史（OR食管=2.02，OR胃=2.29）；对于肺癌而言，吸烟越早（OR=3.63）、烟龄越长（OR=4.13）、吸进部位越深（OR=2.79）均能增加患病概率；饮茶是食管癌（OR=0.73）、胃癌（OR=0.37）、肺癌（OR=0.60）和肝癌（OR=0.27）的共同保护因素。而生吃大蒜对食管癌（OR=0.68）和胃癌（OR=0.64）的保护作用比较确切。[结论]本次研究所发现的有关结果可以为江苏省肿瘤低发及高发地区的防治工作提供参考。     

2018-2019年安徽省碘染色内镜食管癌筛查结果分析

目的食管癌是常见的消化道癌,安徽省自2005年起实施农村癌症早诊早治筛查项目。本研究旨在探讨食管癌筛查人群相关行为、病史及病理检查结果,以及相互关联,为制定更有针对性的筛查方案和防控计划提供依据。方法收集2018-07-01-2019-06-30安徽省全部食管癌筛查数据,应用描述性分析和多元线性相关分析进行数据处理。结果共完成29386人次筛查,男性占52.62%,女性占47.38%;40~49岁组占40.99%,50~59岁组占30.20%。自报吸烟率、饮酒率及饮茶率均<10%;经常吃蔬菜、水果、肉蛋奶类食品及豆类食品的比例分别为97.40%、73.61%、84.29%和80.15%;常吃腌晒食品的占20.07%,常吃油炸食品、烫热食品及霉变食品的比例均<5%;超重或肥胖占41.04%;曾确诊过食管炎的仅占0.4%。病理活检2663份,占筛查人数9.06%。活检共发现各种非增生性病变、增生性病变及癌变1074例,占活检对象的40.33%。各种组织损害的检出率均随年龄的增长而增长(OR=1.84~5.01);男性高于女性(OR=1.30~1.78)。与低体质量相比,肥胖更易检出炎症+基底细胞增生(OR=2.79),但检出癌变的可能性更小(OR=0.43);超重(OR=1.50)及肥胖(OR=2.60)更易检出癌前病变。癌变与水果、腌晒食品及霉变食品摄入频率呈正相关(OR=1.83~2.55),但与饮酒、吸烟无关。癌前病变与霉变食品摄入频率、食管炎和胃肠炎病史呈正相关(OR=2.61~6.16),但与吸烟呈负相关(OR=0.55)。炎症+基底细胞增生则与吸烟、水果摄入频率及胃/十二指肠溃疡呈正相关(OR=1.84~2.78)、与腌晒食品摄入频率呈负相关(OR=0.66)。结论食管癌筛查人群经历过一系列的机制与过程的选择,其相关行为、病史及其与筛查结果的关系与一般人群有明显区别。这些特征为制定更有针对性的筛查和防控计划提供了有益的线索。     

Hospital volume and post-operative mortality after resection for gastric cancer.

AIMS: In low-volume hospitals, expertise in gastric surgery is difficult to maintain because of the decreasing incidence of gastric cancer and the fall of surgery for ulcer disease. We evaluated the prognostic impact of hospital volume on post-operative mortality (POM) in a consecutive series of 1978 patients. METHODS: Information on patients undergoing resection for gastric cancer in the period 1987-97 was retrieved from the Rotterdam Cancer Registry. The relationship between hospital volume and POM was analysed by logistic regression, adjusting for other prognostic factors. RESULTS: POM was 7.9% on average but varied between the 22 hospitals from 3.1% to 15.1% (P=0.15). Hospital volume had no prognostic influence (P=0.74). Prognostic factors were age (70-79 years odds ratio (OR)=3.8, 80+ years OR=6.0), sex (male OR=1.7), stage (IV OR=1.8) and (partial) gastrectomy for cardia cancers (OR=2.0). CONCLUSION: Variation in POM between hospitals was large but not related to hospital volume. For cardia cancer, POM rates were lower after oesophagogastrectomy.     

A Population-based Case-control Study on Risk Factors for Gastric Cardia Cancer in Rural Areas of Linzhou

Gastric cancer is the second most common cause of cancer-related deaths in the world. Although certaindietary factors and lifestyles have been suggested to be associated with gastric carcinogenesis, there have beenfew investigations focusing on rural areas. A case-control study was therefore carried out to investigate the riskfactors of gastric cardia cancer (GCC) in rural areas of Linzhou. A total of 470 newly diagnosed cases of GCCand 470 healthy controls were included. Face-to-face interviews were conducted, using a uniform questionnairecontaining questions on demographics, per capita income, living habits, dietary habits and family history oftumors. The relationship between putative risk factors and GCC was assessed by odds ratios (OR) and their 95%confidence intervals (95%CI) derived from conditional logistic regression model by the COXREG commandusing SPSS 12.00. Multivariate logistic regression analysis was used to evaluate simultaneously the effects ofmultiple factors and other potential confounding factors. Multivariate logistic analysis showed that smoking(OR=1.939, 95%CI:1.097-3.426), alcohol drinking (OR=2.360, 95%CI: 1.292-4.311), hot food consumption(OR=2.034, 95%CI: 1.507-2.745), fast eating (OR=1.616, 95%CI: 1.171-2.230), mouldy food (OR=4.564, 95%CI:2.682-7.767), leftover food (OR=1.881. 95%CI: 1.324-2.671), and family history of tumor (OR=2.831, 95%CI:1.588-5.050) were risk factors for GCC. High per capita income (OR=0.709, 95%CI: 0.533-0.942), high educationlevel (OR=0.354, 95%CI: 0.163-0.765), consumption of fresh fruits (OR=0.186, 95%CI: 0.111-0.311) and vegetables(OR=0.243, 95%CI: 0.142-0.415), and high BMI (OR=0.367, 95%CI: 0.242-0.557) were protective factors forGCC. Our data indicate that unhealthy lifestyle and dietary habits might be important contributors to GCC inthis population.     

福建省胃癌高低发地区居民饮食习惯与营养状况的调查分析

目的:通过对福建省胃癌高低发区居民饮食习惯与营养状况的调查研究,为胃癌防治提供一定参考依据。方法:选择胃癌高低发区居民进行对照研究,通过自行设计饮食状况调查表进行入户流行病学现场调查,对饮食习惯、营养素摄入量和膳食结构等进行比较分析。结果:食用油炸食品和煎炸食品的频率(有时吃和经常吃)高发区(分别为33.3%和36.2%)高于低发区(分别为23.7%和26.1%),食用凉拌或生吃食品、盐渍食品和蒸、熬、炒食品的频率高发区则显著低于低发区;两地区居民的主要营养素来源以植物性食品为主,各种营养素从动物性食品和植物性食品中摄取的比例很接近;与膳食指南建议量作比较,高发区居民蔬菜类、豆类、蛋类和奶类食品摄入量低于参考值,低发区居民水果类、蛋类、豆类和奶类食品摄入量未达到建议摄入量,高发区居民每日蔬菜和豆类食品摄入量均低于低发区;低发区居民葱和生姜每日食用量分别是高发区的4.6倍和14.0倍。结论:高低发区居民饮食烹调方法和膳食结构存在较大差异,高发区居民的烹调方法可能是胃癌高发的危险因素,并且膳食结构不如低发区合理。低发区居民喜食葱和生姜可能是胃癌低发的重要保护因素。     

Family history of cancer and risk of esophageal and gastric cancers in the United States

The worldwide rates for histology- and subsite-specific types of esophageal and gastric cancer reveal strikingly divergent patterns. The contribution of environmental and genetic factors has been explored in several high-incidence areas, but data on genetic influences are scarce for Western countries. Using data from a multicenter, population-based, case-control study on 1,143 cases and 695 controls in the United States, we evaluated whether a family history of digestive or other cancers was associated with an increased risk of esophageal adenocarcinoma (n = 293), esophageal squamous cell carcinoma (n = 221), gastric cardia adenocarcinoma (n = 261) or non-cardia gastric adenocarcinoma (n = 368). After adjusting for other risk factors, individuals reporting a family history of digestive cancers experienced no increased risk of either type of esophageal cancer but they were prone to adenocarcinomas of the gastric cardia [odds ratio (OR) = 1.34, 95% confidence interval (CI) 0.91-1.97] and non-cardia segments (OR =1.46, 95% CI 1.03-2.08). This familial tendency, particularly for non-cardia gastric tumors, was largely explained by an association with family history of stomach cancer (OR = 2.52, 95% CI 1.50-4.23). In addition, family history of breast cancer was associated with increased risks of esophageal adenocarcinoma (OR = 1.74, 95% CI 1.07-2.83) and non-cardia gastric adenocarcinoma (OR = 1.76, 95% CI 1.09-2.82). Also seen were non-significant familial associations of esophageal squamous-cell cancer with prostate cancer as well as non-cardia gastric cancer with leukemia and brain tumors, though these relationships must be interpreted with caution. Our data point to the role of familial susceptibility to gastric cancer, but not to any form of esophageal cancer, in the United States.     

Evaluating gastric cancer misclassification: a potential explanation for the rise in cardia cancer incidence.

BACKGROUND: Reports of dramatic increases in gastric cardia cancer incidence warrant concern. However, the recent introduction of a separate diagnostic code, the lack of a consensus definition of the cardia area, and the accelerating interest in cardia cancer may affect classification practices. Little is known about the magnitude of cardia cancer misclassification in large cancer registries. METHODS: In a well-defined Swedish population (1.3 million), we uniformly classified all patients with newly diagnosed gastric adenocarcinoma (from 1989 through 1994) with respect to gastric subsite, and we used this patient group as our gold standard. We then evaluated the completeness of the Swedish Cancer Registry in registering gastric adenocarcinomas against this gold standard and, further, assessed the completeness of cardia cancer registration and the rate of falsely included cases to estimate the potential impact on observed incidence trends. RESULTS: Our gold standard contained 1337 case subjects with gastric adenocarcinoma. Overall, the Swedish Cancer Registry was 98% complete with regard to gastric adenocarcinomas and had a 4% rate of falsely included cases. The completeness of coding cardia cancer was only 69%, and the positive predictive value for cardia cancer was 82%, with no improvement over time. CONCLUSIONS: Although overall completeness of gastric cancer registration by the Swedish Cancer Registry was excellent, accuracy in registering cardia tumors was surprisingly low. Our estimates suggest that true cardia cancer incidence could be up to 45% higher or 15% lower than that reported in the Cancer Registry. This margin of error could accommodate the observed increase in cardia cancer in Sweden. Therefore, secular trends in cardia cancer incidence should be interpreted cautiously.