Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI.
Department of Health and Human Services, Metabolic Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health (NIH), Bethesda, MD.
Nicotine Tob Res. 2019 Jul 17;21(8):1045-1050. doi: 10.1093/ntr/nty115.
The Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study demonstrated that β-carotene supplementation increases lung cancer incidence in smokers. Further, cigarettes with higher tar and nicotine content are associated with a higher risk of lung cancer. However, no studies have examined whether the increased risk associated with β-carotene supplementation in smokers varies by the tar or nicotine content of cigarettes.
The ATBC Study was a randomized, double-blind intervention trial conducted in southwest Finland. A total of 29 133 male smokers, aged 50-69 years, were enrolled and randomly assigned to one of four groups (α-tocopherol, β-carotene, both, or placebo). Cox proportional hazards models were used to estimate the hazard ratio (HR) and 95% confidence intervals (CI) of lung cancer risk by β-carotene trial assignment stratified by a priori categories of cigarette tar and nicotine content.
The β-carotene supplementation group had significantly higher risk of developing lung cancer in all categories of tar content (yes vs. no β-carotene supplementation-ultralight cigarettes [≤7 mg tar]: HR = 1.31, 95% CI = 0.91 to 1.89; nonfiltered cigarettes [≥21 mg tar]: HR = 1.22, 95% CI = 0.91 to 1.64; p for interaction = .91). Similarly, there was no interaction with nicotine content (yes vs. no β-carotene supplementation-ventilated cigarettes [≤0.8 µg nicotine]: HR = 1.23, 95% CI = 0.98 to 1.54; nonfiltered cigarettes [≥1.3 µg nicotine]: HR = 1.22, 95% CI = 0.91 to 1.64; p for interaction = .83).
These findings support the conclusion that supplementation with β-carotene increases the risk of lung cancer in smokers regardless of the tar or nicotine content of cigarettes smoked. Our data suggest that all smokers should continue to avoid β-carotene supplementation.
Previous studies demonstrated that β-carotene supplementation increases risk of lung cancer in smokers. This study moves the field forward by examining the potential for modification of risk of lung cancer with different levels of tar and nicotine in cigarettes smoked, as interaction with carcinogens in these components of cigarette smoke is hypothesized to be the mechanism by which β-carotene increases risk. Our study provides evidence that the increased risk of lung cancer in smokers who take β-carotene supplements is not dependent upon the tar or nicotine level of cigarettes smoked and suggests that all smokers should continue to avoid β-carotene supplementation.
α-生育酚、β-胡萝卜素防癌（ATBC）研究表明，β-胡萝卜素补充剂会增加吸烟者肺癌的发病率。此外，焦油和尼古丁含量较高的香烟与肺癌风险增加有关。然而，尚无研究探讨吸烟者β-胡萝卜素补充剂相关的风险增加是否因所吸烟草的焦油和尼古丁含量而异。
ATBC 研究是在芬兰西南部进行的一项随机、双盲干预试验。共纳入 29133 名年龄在 50-69 岁的男性吸烟者，并将其随机分配至四个组（α-生育酚、β-胡萝卜素、两者联合或安慰剂）。采用 Cox 比例风险模型，按事先设定的香烟焦油和尼古丁含量类别，对β-胡萝卜素试验分配分层，估计肺癌风险的风险比（HR）和 95%置信区间（CI）。
在所有焦油含量类别中（有 vs. 无β-胡萝卜素补充剂-超低焦油香烟[≤7mg 焦油]：HR=1.31，95%CI=0.91 至 1.89；非过滤香烟[≥21mg 焦油]：HR=1.22，95%CI=0.91 至 1.64；交互作用 P 值=0.91），β-胡萝卜素补充组肺癌发病风险显著更高。同样，与尼古丁含量也无交互作用（有 vs. 无β-胡萝卜素补充剂-通风型香烟[≤0.8μg 尼古丁]：HR=1.23，95%CI=0.98 至 1.54；非过滤香烟[≥1.3μg 尼古丁]：HR=1.22，95%CI=0.91 至 1.64；交互作用 P 值=0.83）。
这些发现支持β-胡萝卜素补充剂会增加吸烟者肺癌风险的结论，与所吸烟草的焦油或尼古丁含量无关。我们的数据表明，所有吸烟者应继续避免β-胡萝卜素补充剂。
先前的研究表明，β-胡萝卜素补充剂会增加吸烟者患肺癌的风险。本研究通过研究不同焦油和尼古丁水平的香烟对肺癌风险的潜在修饰作用，向前推进了该领域的研究，因为香烟烟雾中的这些成分中的致癌物质相互作用被假设为β-胡萝卜素增加风险的机制。我们的研究提供了证据，表明吸烟者服用β-胡萝卜素补充剂会增加患肺癌的风险，这与他们所吸烟草的焦油或尼古丁含量无关，并表明所有吸烟者应继续避免β-胡萝卜素补充剂。
