RANDOMIZED TRIAL TO EVALUATE SCREENING FOR COLON CANCER

明尼苏达州结肠癌控制研究（CCCS），一项随机对照 试验，旨在评估粪便潜血的有效性 试验（Hemoccult）降低结直肠癌死亡率。 共 在1975年至1977年期间招募了46，551名年龄在50至80岁之间的人， 随机分配到每年筛查一次的组，每两年筛查一次的组， 组或对照组。 筛查结果呈阳性的人 在明尼苏达大学提供结肠镜检查。 的 1992年2月结束的研究的筛查和诊断阶段 和初步结果，发表在1993年5月13日的《新 英国医学杂志显示， 结直肠癌死亡率在每年筛查组。 有一个 两年一次的死亡率下降了7%，但并不显著。 结果表明，考虑到有利的阶段分布， 生存率，累积结直肠癌死亡率， 两年期组应比对照组进一步下降， 然而，还需要采取更多的后续行动，以确定 模式. 此外，迄今为止的初步结果表明， 只有通过大量的事件才能澄清的影响， 延长随访时间并累积更多事件。 这项研究已经 由1994年12月17日到期的NCI合同支持。 这项建议是继续跟踪队列五年， 确定结直肠癌的病例和死亡人数，并进行一系列 统计分析，以解决一些重要问题， 每两年一次筛查和亚组（年龄和性别）的有效性 方面的影响. 这两个问题对成本都有重大影响 与一般人群的筛查有关。 其他重要问题， 地址包括结肠镜检查和隐血的相对贡献， 在每年筛查组中观察到的死亡率降低， 息肉切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、 前置时间和长度偏差。 建议利用已制定的程序， 确定事件，收集验证支持文档，跟踪 队列和回顾死亡。 一系列广泛的统计分析 包括许多已经开发的， 用于处理与全面、综合和 筛查有效性和筛查特征的评估 test.

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.