PHASE IV CHEMOPREVENTION TRIAL BETA-CAROTENE/RETINOL

这项化学预防试验测试了视黄醇的功效， β-胡萝卜素在预防肺癌两个相关的高风险 人口： (a)从保险公司招募的重度吸烟者 （B）目前和以前的工人， 职业性石棉暴露 补偿和就业来源。 双盲，两个- 随机分组方案比较安慰剂组和每日 30毫克β-胡萝卜素加25，000 IU视黄醇的组合。 我们 将招募合格的石棉暴露受试者， 巴尔的摩地区。 我们将参与实施一项成本- 有效的、整合良好的多诊所战略， 西雅图项目管理和数据协调中心 分析. 在新的补助期的头两年（1988- 91)我们将招募800名受试者 根据多中心协议。 我们将提供所有 必要的数据，以评估权责发生制，协调和成本， 地理上分散的诊所站点，以生成最佳估计 全面收生的余下需要为何，以及 起来 目前的假设和预测表明， 规模有效性试验将能够检测出显著的 降低高危人群的肺癌发病率 在13，000名吸烟者中， 4000名接触石棉的受试者

This chemoprevention trial tests the efficacy of retinol and beta-carotene in preventing lung cancer in two related high-risk populations: (a) heavy smokers recruited from insurance-based sources, and (b) current and former workers with heavy occupational asbestos exposure recruited from workers' compensation and employment-based sources. The double-blind, two- arm randomized protocol compares placebos with a daily combination of 30 mg beta-carotene plus 25,000 IU retinol. We will recruit eligible asbestos-exposed subjects from the Baltimore area. We will participate in implementing a cost- effective, well-integrated, multi-clinic strategy, with the Seattle-based coordinating center for project management and data analysis. During the first 2 years of the new grant period (1988- 91) we will recruit and enroll 800 subjects randomized according to the multi-center protocol. We will provide all necessary data to evaluate accrual, coordination, and costs in geographically-dispersed clinic sites to generate best estimates of the remaining needs for the full-scale enrollment and follow- up. Current assumptions and projections indicate that the full- scale Efficacy Trial will be capable of detecting significant reductions in lung cancer incidence in the high-risk groups combined, and in either subgroup alone, with 13,000 smokers and 4000 asbestos-exposed subjects.