Duffield-Lillico Anna J, Reid Mary E, Turnbull Bruce W, Combs Gerald F, Slate Elizabeth H, Fischbach Lori A, Marshall James R, Clark Larry C
Arizona Cancer Center, Tucson, Arizona 85724-5024, USA.
Cancer Epidemiol Biomarkers Prev. 2002 Jul;11(7):630-9.
The Nutritional Prevention of Cancer Trial was a randomized, clinical trial designed to evaluate the efficacy of selenium as selenized yeast (200 microg daily) in preventing the recurrence of nonmelanoma skin cancer among 1312 residents of the Eastern United States. Original secondary analyses through December 31, 1993 showed striking inverse associations between treatment and the incidence of total [hazard ratio (HR) = 0.61, 95% confidence interval (CI) = 0.46-0.82], lung, prostate, and colorectal cancer and total cancer mortality. This report presents results through February 1, 1996, the end of blinded treatment. Effect modification by baseline characteristics is also evaluated. The effects of treatment overall and within subgroups of baseline age, gender, smoking status, and plasma selenium were examined using incidence rate ratios and Cox proportional hazards models. Selenium supplementation reduced total (HR = 0.75, 95% CI = 0.58-0.97) and prostate (HR = 0.48, 95% CI = 0.28-0.80) cancer incidence but was not significantly associated with lung (HR = 0.74, 95% CI = 0.44-1.24) and colorectal (HR = 0.46, 95% CI = 0.21-1.02) cancer incidence. The effects of treatment on other site-specific cancers are also described. The protective effect of selenium was confined to males (HR = 0.67, 95% CI = 0.50-0.89) and was most pronounced in former smokers. Participants with baseline plasma selenium concentrations in the lowest two tertiles (<121.6 ng/ml) experienced reductions in total cancer incidence, whereas those in the highest tertile showed an elevated incidence (HR = 1.20, 95% CI = 0.77-1.86). The Nutritional Prevention of Cancer trial continues to show a protective effect of selenium on cancer incidence, although not all site-specific cancers exhibited a reduction in incidence. This treatment effect was restricted to males and to those with lower baseline plasma selenium concentrations.
癌症营养预防试验是一项随机临床试验，旨在评估作为硒酵母（每日200微克）的硒对美国东部1312名居民预防非黑色素瘤皮肤癌复发的疗效。截至1993年12月31日的原始二次分析显示，治疗与总癌症发病率[风险比（HR）=0.61，95%置信区间（CI）=0.46 - 0.82]、肺癌、前列腺癌和结直肠癌发病率以及总癌症死亡率之间存在显著的负相关。本报告呈现了截至1996年2月1日（盲法治疗结束）的结果。还评估了基线特征的效应修饰。使用发病率比和Cox比例风险模型检查了总体治疗效果以及基线年龄、性别、吸烟状况和血浆硒亚组内的治疗效果。补充硒降低了总癌症（HR = 0.75，95% CI = 0.58 - 0.97）和前列腺癌（HR = 0.48，95% CI = 0.28 - 0.80）的发病率，但与肺癌（HR = 0.74，95% CI = 0.44 - 1.24）和结直肠癌（HR = 0.46，95% CI = 0.21 - 1.02）的发病率无显著关联。还描述了治疗对其他特定部位癌症的影响。硒的保护作用仅限于男性（HR = 0.67，95% CI = 0.50 - 0.89），并且在既往吸烟者中最为明显。基线血浆硒浓度处于最低两个三分位数（<121.6纳克/毫升）的参与者总癌症发病率降低，而处于最高三分位数的参与者发病率升高（HR = 1.20，95% CI = 0.77 - 1.86）。癌症营养预防试验继续显示硒对癌症发病率有保护作用，尽管并非所有特定部位的癌症发病率都有所降低。这种治疗效果仅限于男性和基线血浆硒浓度较低的人群。
