Prostate, Lung, Colorectal and Ovarian (PLCO) Screening Trial

前列腺、肺、结直肠和卵巢（PLCO）癌症筛查试验是一项大规模的随机对照试验，旨在确定某些筛查试验是否会减少这些癌症的死亡人数。PLCO是一项多机构临床试验，在美国各地的10个地点进行，地理和人口统计学上各不相同。PLCO招募了154 942名男性和女性参与者。PLCO参与者与美国一般人口相当。从参与者那里收集生活方式、饮食和危险因素信息。干预组在入组时接受肺癌后前位（PA）胸部X线检查，每年进行4次筛查（不吸烟者除外，他们每年接受3次筛查），并在第4次或第6次年度筛查间隔时再次接受可弯曲乙状结肠镜检查（FSG），具体取决于入组筛查结直肠癌的时间。对于前列腺癌，男性每年接受6次前列腺特异性抗原（PSA）筛查和4次直肠指检（DRE）。妇女每年用CA-125抗原筛查卵巢癌6次，每年用经阴道超声（TVU）筛查4次。常规护理（对照）组接受初级保健提供者的定期保健。从干预组中采集全血、连续血清样本和一份血浆样本。通过与癌症流行病学和遗传学部门（DCEG）合作，将这些样本的等分试样储存在PLCO生物储存库中。常规护理组提供口腔细胞DNA样品，这些样品也储存在PLCO生物储存库中。PLCO生物储存库目前拥有超过290万份标本，可用于病原学和早期标志物研究。PLCO正在收集来自那些患有癌症的参与者的结肠直肠、卵巢、前列腺和肺肿瘤组织。然后构建组织微阵列。 研究设计 PLCO是一项双臂随机试验，其中超过38，000名男性接受了肺癌，结直肠癌和前列腺癌的筛查，约39，000名女性接受了肺癌，结直肠癌和卵巢癌的筛查。同样数量的男性和女性作为对照组参与，继续他们通常的医疗保健做法。入组时的合格年龄范围为55-74岁。筛选和对照受试者从随机化开始至少随访13年，以确定癌症和死亡确定，以确定筛选方案是否导致疾病特异性死亡率降低。 从所有参与者中收集基线信息，包括人口统计学特征、研究中癌症的已知风险因素和筛查史。此外，参与者完成了饮食，食物频率问卷，随后是一份风险因素问卷，补充了他们登记时提供的基线数据。将每次筛选访视时采集的血液样本处理成单独的组分，并储存用于未来的分子分析。对照参与者提供颊细胞DNA。干预组和对照组的参与者都完成了一份饮食调查问卷。所有参与者还提供年度健康状况信息。 在几个筛选地点作出了特别努力，加强征聘少数族裔。密歇根州底特律的一个地点集中努力增加非裔美国人的参与。位于丹佛的一个网站，CO雇用了讲西班牙语的工作人员，以增加在PLCO注册的西班牙裔美国人的数量。 BIOREPOSITORY PLCO生物储存库包含在6个筛选年期间收集的约290万份生物标本。这些样本包括血清、血浆和血沉棕黄层以及DNA样本。这些标本是癌症研究的宝贵资源。使PLCO生物标本具有独特价值的一些特征包括： - 大样本量允许统计功效 - 在癌症诊断前前瞻性收集标本 - 在每年6次的筛查中收集系列标本 - 详细的背景和临床数据可用 PLCO病因学和早期标志物研究（EEMS）部分是PLCO试验的组成部分。PLCO EEMS有两个主要重点：调查癌症的环境，生物化学和遗传风险因素的病因学研究;以及旨在开发早期疾病的可重复，诊断就绪的生物标志物的早期检测研究。PLCO EEMS直接解决国家癌症研究所的以下战略重点： - 了解癌症的原因和机制 - 改善早期检测和诊断

The Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial is a large scale, randomized controlled trial to determine whether certain screening tests will reduce the number of deaths from these cancers. PLCO is a multi-institutional clinical trial being conducted at ten sites, geographically and demographically disparate, around the U.S. This controlled trial is a Phase III trial conducting human subjects research. PLCO enrolled 154,942 male and female participants. The PLCO participants are comparable to the general United States population. Life style, dietary and risk factor information was collected from participants. The intervention arm received for lung cancer, posterior-anterior (PA) chest x-ray annually for four screens (except never smokers who received three annual screens), flexible sigmoidoscopy (FSG) at enrollment and again at the fourth or sixth annual screening interval depending on time of enrollment to screen for colorectal cancer. For prostate cancer, men received six annual prostate screens with prostate-specific antigen (PSA) and four digital rectal exams (DRE). Women were screened for ovarian cancer with CA-125 antigen for six annual screens and with transvaginal ultrasound (TVU) for four annual screens. The usual care (control) arm received regular health care from their primary care provider. Whole blood, sequential serum samples and one plasma sample were collected from the intervention arm. Aliquots from these samples are stored in the PLCO Biorepository through collaboration with the Division of Cancer Epidemiology and Genetics (DCEG). The usual care arm provided buccal cell DNA samples which are also stored in the PLCO Biorepository. The PLCO Biorepository currently has over 2.9 million specimens that can be used for etiologic and early marker studies. PLCO is collecting colo-rectal, ovarian, prostate and lung tumor tissue from those participants who have developed cancer. Tissue microarrays are then constructed. STUDY DESIGN The PLCO is a two-armed, randomized trial in which more than 38,000 men were screened for lung, colorectal, and prostate cancers and approximately 39,000 women were screened for lung, colorectal, and ovarian cancers. Equal numbers of men and women participating as controls continue their usual medical care practices. The eligible age range at entry was 55-74 years. Both screened and control participants are to be followed for at least 13 years from randomization for cancer and death ascertainment to determine if the screening regimen results in reduced disease-specific mortality. Baseline information including demographic characteristics, known risk factors for the cancers under study, and screening history were collected from all participants. In addition, participants completed dietary, food frequency questionnaires and subsequently a risk factor questionnaire that supplements the baseline data provided at the time they enrolled. Blood samples collected at each screening visit were processed into separate components and stored for future molecular analyses. Control participants provided Buccal cell DNA. Participants in both the intervention and control arms completed a dietary questionnaire. All participants also provide annual health status information. Special efforts made to enhance the recruitment of minorities occurred at several screening locations. One site in Detroit, MI focused efforts on increasing the participation of African Americans. A site in Denver, CO hired Spanish speaking staff to enhance the number of Hispanic Americans enrolled in PLCO. BIOREPOSITORY The PLCO Biorepository contains approximately 2.9 million biologic specimens collected during the six screening years. These samples include serum, plasma and buffy coat and DNA samples. These specimens are an invaluable resource for cancer research. Some of the characteristics that make the PLCO biospecimens uniquely valuable include: - Large sample size allows statistical power - Specimens are collected prospectively, before cancer diagnosis - Serial specimens are collected at each of the 6 annual screenings - Detailed background and clinical data are available The PLCO Etiology and Early Marker Studies (EEMS) component is an integral part of the PLCO Trial. The PLCO EEMS has two main focuses: etiologic studies that investigate the environmental, biochemical and genetic risk factors for cancer; and early detection studies that aim to develop reproducible, diagnostics-ready biomarkers of early disease. The PLCO EEMS directly addresses the following strategic priorities of the National Cancer Institute: - Understand the causes and mechanisms of cancer - Improve early detection and diagnosis