RANDOMIZED TRIAL TO EVALUATE SCREENING FOR COLON CANCER

明尼苏达州结肠癌控制研究(CCCS)，随机对照 试验旨在评估粪便潜血的有效性 测试(隐血)在降低结直肠癌死亡率方面。总计 在1975至1977年间招募了46,551名年龄在50岁至80岁之间的人， 随机分配到每年筛查的组，每两年筛查一次 组或对照组。筛查试验呈阳性的有 在明尼苏达大学做了结肠镜检查。这个 1992年2月结束的研究的筛查和诊断阶段 研究的初步结果发表在1993年5月13日出版的《新月刊》上。 《英格兰医学杂志》显示， 年度筛查组的结直肠癌死亡率。有一个 两年一次的组死亡率降低7%不显著。 得出的结论是，鉴于有利的阶段分布和 存活率，结直肠癌的累积死亡率 与对照组相比，两年期组应进一步下降， 然而，有必要进行额外的跟进，以确定实际的 模式。此外，到目前为止的初步结果表明 只有通过更多的事件才能阐明的影响 延长了对更多事件的跟踪和应计费用。这项研究一直在进行 由1994年12月17日到期的NCI合同支持。 这项建议是在五年内继续跟踪队列以 确定结直肠癌的病例和死亡情况，并进行一系列 统计分析，以解决一些重要问题，包括 每两年进行一次筛查的效果和亚组(年龄和性别) 效果。这两个问题都对成本有重大影响 与普通人群中的筛查有关。要解决的其他重要问题 内容包括结肠镜检查和隐血检查对 观察到的每年筛查组的死亡率下降和 息肉摘除对结直肠癌后续发病率的影响。 提出了一些其他分析，这些分析将提供重要的 关于筛选的信息。其中包括：合规性、测试性能、 提前期和长度偏差。 建议利用已开发的程序来 确定事件、收集支持文档以进行验证、跟踪 队列和复查死亡病例。一系列广泛的统计分析 被提议，包括许多已经开发的和 用于解决与全面的 筛查效果评价及筛查特点 测试。

The Minnesota Colon Cancer Control Study (CCCS), a randomized controlled trial, is designed to evaluate the effectiveness of a fecal occult blood test (Hemoccult) in reducing mortality from colorectal cancer. A total of 46,551 individuals age 50 to 80 were recruited between 1975 and 1977 and randomly assigned to an annually screened group, a biennially screened group or a control group. Those with a positive screening test were offered a colonoscopy examination at the University of Minnesota. The screening and diagnostic phases of the study concluded in February, 1992 and the initial results, published in the May 13, 1993 issue of the New England Journal of Medicine showed a significant 33 percent reduction in colorectal cancer mortality in the annual screened group. There was a nonsignificant seven percent mortality reduction in the biennial group. It was concluded that in view of the favorable stage distribution and survival rates, the cumulative colorectal cancer mortality rates for the biennial group should decline further relative to the control group, however, additional follow-up is necessary to determine the actual patterns. In addition, the preliminary results to date suggest age effects which can only be clarified with a larger number of events through extended follow-up and accrual of more events. The study has been supported by an NCI contract which expires December 17, 1994. This proposal is to continue to follow the cohort for five years to ascertain cases and deaths of colorectal cancer and perform a series of statistical analyses in order to address some important issues including the effectiveness of biennially screening and subgroup (age and sex) effects. Both of these issues have significant implications on the costs related to screening in the general population. Other important issues to address include the relative contribution of colonoscopy and Hemoccult to the observed mortality reduction in the annually screened group and the effect of polyp removal on the subsequent incidence of colorectal cancer. A number of other analyses are proposed which will provide important information on screening. These include: compliance, test performance, lead time and length bias. It is proposed to utilize the procedures that have been developed to ascertain events, collect supporting documentation for validation, track the cohort and review deaths. An extensive series of statistical analyses are proposed, including many which have already been developed and utilized to address specific questions relevant to a comprehensive assessment of screening efficacy and the characteristics of the screening test.