Effects of selenium supplementation for cancer prevention in patients with carcinoma of the skin a randomized controlled trial - A randomized controlled trial
Effects of selenium supplementation for cancer prevention in patients with carcinoma of the skin a randomized controlled trial - A randomized controlled trial
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DOI：
10.1001/jama.276.24.1957
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发表时间：
1996-12-25
影响因子：
120.7
通讯作者：
Taylor, JR
中科院分区：
文献类型：
--
作者：
Clark, LC;Combs, GF;Taylor, JR
客观。-为了确定是否硒的营养补充剂将降低癌症的发病率。多中心、双盲、随机、安慰剂对照的癌症预防试验。美国东部七家皮肤科诊所的病人。从1983年到1991年，共有1312例有皮肤基底细胞癌或鳞状细胞癌病史的患者（平均年龄63岁，范围18-80岁）被随机分组。患者接受平均（SD）4.5（2.8）年的治疗，总随访时间为6.4（2.0）年。每天口服200 μ g硒或安慰剂。主要结果测量。试验的主要终点是皮肤基底细胞癌和鳞状细胞癌的发生率。次要终点于1990年确定，为全因死亡率和总癌症死亡率、总癌症发病率以及肺癌、前列腺癌和结直肠癌的发病率。结果。-经过8271人年的随访，硒治疗对基底细胞或鳞状细胞皮肤癌的发病率没有显著影响。补硒组患者新发基底细胞皮肤癌377例，对照组350例（相对危险度[RR]，1.10; 95%可信区间[CI]，0.95-1.28），硒组新发鳞状细胞皮肤癌218例，对照组新发鳞状细胞皮肤癌190例（RR，1.14; 95% CI，0.93-1.39）。次要终点分析显示，与对照组相比，硒治疗患者的全因死亡率无显著降低（硒组死亡108例，对照组死亡129例[RR，0.83; 95% CI，0.63-1.08]）和总癌症死亡率显著降低（硒治疗组29例死亡，对照组57例死亡[RR，0.50; 95% CI，0.31-0.80]），总癌症发病率（硒组77例癌症，对照组119例[RR，0.63; 95%CI，0.47-0.85]），以及肺癌、结直肠癌和前列腺癌的发病率。首先，由于硒组的总癌症死亡率和总癌症发病率明显降低，试验的盲态阶段提前停止。没有发生硒中毒的病例。硒治疗不能防止皮肤基底细胞癌或鳞状细胞癌的发展。然而，次要终点分析的结果支持这一假设，即补充硒可能会降低几个部位的癌症的发病率和死亡率。硒的这些作用需要在适当设计的独立试验中得到证实，然后才能提出关于硒补充剂的新的公共卫生建议。
Objective.-To determine whether a nutritional supplement of selenium will decrease the incidence of cancer.Design.-A multicenter, double-blind, randomized, placebo-controlled cancer prevention trial.Setting.-Seven dermatology clinics in the eastern United States.Patients. A total of 1312 patients (mean age, 63 years; range, 18-80 years) with a history of basal cell or squamous cell carcinomas of the skin were randomized from 1983 through 1991. Patients were treated for a mean (SD) of 4.5 (2.8) years and had a total follow-up of 6.4 (2.0) years.Interventions.-Oral administration of 200 mu g of selenium per day or placebo.Main Outcome Measures.-The primary end points for the trial were the incidences of basal and squamous cell carcinomas of the skin. The secondary end points, established in 1990, were all-cause mortality and total cancer mortality, total cancer incidence, and the incidences of lung, prostate, and colorectal cancers.Results.-After a total follow-up of 8271 person-years, selenium treatment did not significantly affect the incidence of basal cell or squamous cell skin cancer. There were 377 new cases of basal cell skin cancer among patients in the selenium group and 350 cases among the control group (relative risk [RR], 1.10; 95% confidence interval [CI], 0.95-1.28), and 218 new squamous cell skin cancers in the selenium group and 190 cases among the controls (RR, 1.14; 95% CI, 0.93-1.39). Analysis of secondary end points revealed that, compared with controls, patients treated with selenium had a nonsignificant reduction in all-cause mortality (108 deaths in the selenium group and 129 deaths in the control group [RR, 0.83; 95% CI, 0.63-1.08]) and significant reductions in total cancer mortality (29 deaths in the selenium treatment group and 57 deaths in controls [RR, 0.50; 95% CI, 0.31-0.80]), total cancer incidence (77 cancers in the selenium group and 119 in controls [RR, 0.63; 95% CI, 0.47-0.85]), and incidences of lung, colorectal, and prostate cancers. Primarily because of the apparent reductions in total cancer mortality and total cancer incidence in the selenium group, the blinded phase of the trial was stopped early. No cases of selenium toxicity occurred.Conclusions.-Selenium treatment did not protect against development of basal or squamous cell carcinomas of the skin. However, results from secondary end-point analyses support the hypothesis that supplemental selenium may reduce the incidence of, and mortality from, carcinomas of several sites. These effects of selenium require confirmation in an independent trial of appropriate design before new public health recommendations regarding selenium supplementation can be made.