No Link Between Androgen Levels and Risk for Prostate Cancer
研究发现，雄激素水平与前列腺癌发病之间没有关联
January 29, 2007 — Blood levels of androgens and other sex hormones do not appear to be related to the risk for prostate cancer. The finding comes from a huge pooled analysis of data from 18 studies, published online January 29 in the Journal of the National Cancer Institute. It \"confirms the lack of evidence to support an androgen–prostate cancer hypothesis,\" according to an accompanying editorial.
2007年1月29日— 血中的雄激素及其他性激素水平可能与前列腺癌的发病并没有关联。该结论是在对18项研究的数据进行大规模的汇总分析后得到的，并发表在1月29日的《全国癌症研究学会杂志》网络版上。这“证明认为雄激素水平与前列腺癌发病有关联的假说还缺乏足够的证据。”文章的社论指出。
A link between elevated androgen levels and an increase in the risk for prostate cancer has been widely hypothesized, despite little supportive epidemiologic evidence, comment Paul Godley, MD, PhD, and colleagues from the University of North Carolina, Chapel Hill, in an accompanying editorial. Androgens play a key role in the development of the prostate, and androgen suppression in advanced cancer can lead to a dramatic regression of the disease, they point out. Hence, there has been an \"intense and sustained interest in confirming an androgen-driven hypothesis,\" they add.
过去，人们一直认为雄激素水平升高与前列腺癌发病风险升高之间存在关联，尽管支持这一假说的流行病学资料很少。在文章的社论中，Paul Godley博士和他的同事，来自北卡罗来纳大学的Chapel Hill做出评论说。他们指出，雄激素在前列腺的发生过程中有着很重要的作用，抑制雄激素可以极大的控制晚期前列腺癌的进展。因而，一直以来“人们就对证明雄激素可促进前列腺癌发病这一假说有着强烈的持久的兴趣”，他们补充说。
The new analysis provides no evidence of such a link, however. An international collaboration of researchers, headed by Andrew Roddam, DPhil, from the University of Oxford, United Kingdom, took another look at the original data collected in the 18 studies, consisting of 3886 men with prostate cancer and 6438 controls. Each of the studies had looked at the relation between androgens and the risk for prostate cancer, but the results were inconclusive; some suggested a positive association, but many of the studies had limited power, the researchers comment.
然而，新的分析结果显示两者之间并无关联。由英国牛津大学的Andrew Roddam博士领衔、各国间研究人员合作对这18项研究所收集的原始数据重新进行了分析。这18项研究共包括了3886名前列腺癌病人和对照组6438名研究对象。每一项研究均对雄激素水平与前列腺癌发病风险之间的关联进行了研究，但均未得出确定结果。一些研究认为两者存在相关性，但这些研究大都具有一定的局限性。研究者们评价说。
In the new analysis, all of the data from these previous studies were pooled together. The team looked at blood samples taken before the men developed prostate cancer and analyzed serum concentrations of testosterone, free testosterone, dihydrotestosterone, dehydroepiandrosterone sulfate, androstenedione, androstanediol glucuronide, estradiol, and calculated free estradiol. They found no significant relation between the serum levels of any of these hormones and the risk of developing prostate cancer.
在把以前所有的数据整合后，研究者们对数据进行了新的分析。他们检查了前列腺癌病人发病前的血样，并分析了血清中睾酮、游离睾酮、双氢睾酮、硫酸脱氢表雄酮、雄烯二酮、葡糖苷酸雄烷、雌二醇、游离雌二醇的浓度。结果他们发现血清中上述任一激素的浓度均与前列腺癌的发病没有关联。
This is an \"impressive pooled analysis\" that enhances \"our understanding of prostate cancer epidemiology,\" the editorialists comment. It also offers a new opportunity, because it now \"obliges the scientific community to move past a seductive, clinically relevant, and biologically plausible hypothesis and get on with the difficult task of exploring, analyzing, and characterizing modifiable risk factors for prostate cancer.\"
这一汇总分析有着很重要的意义，它加深了我们对前列腺癌流行病学的认识。社论作者评价说。同时它又为我们提供了一个新的机遇，因为它“迫使学术界放弃这一诱人的、在生物学上似乎可信的认为两者在临床上具有相关性的假说，并推动他们去探索、分析并确定前列腺癌发病的危险因子。”
However, the question of where to go from here will take some serious discussion and debate, Dr. Godley commented to Medscape Oncology. \"I'm pretty sure that there is not an obvious answer to what are the most likely causes of prostate cancer,\" he said.
但是，从何处着手这个问题尚需要经过讨论和辩证。Godley博士在《Medscape Oncology》杂志上发表评论说。“我确信目前对前列腺癌的主要病因这个问题尚无明确的答案。”他说。
The finding also raises questions about the use of finasteride for the prevention of prostate cancer. This drug, a 5-alpha reductase inhibitor, blocks the conversion of testosterone into the more potent dihydrotestosterone. In the Prostate Cancer Prevention Trial, previously reported by Medscape Oncology, finasteride reduced the occurrence of prostate cancer by approximately 25% during a 7-year period, although the risk for high-grade tumors was higher in the treated group than in the untreated group. These results offer a \"tantalizing possibility for effective prostate cancer chemoprevention,\" add the editorialists, but the hypothesis that provided the theoretical foundation for this trial has now been \"convincingly debunked\" by the latest finding.
这一研究结果也使人们对非那雄胺预防前列腺癌的作用产生了怀疑。非那雄胺是一种5-α还原酶抑制剂，它能阻断睾酮转化为效能更强的二氢睾酮。据先前发表于《Medscape Oncology》上预防前列腺癌的实验显示，在为期七年的研究中，非那雄胺能使前列腺癌的发病率降低约25%，然而实验组发生高级前列腺癌的风险比对照组高。这一研究结果使化学方法有效预防前列腺癌成为可能。社论作者说。但为这一实验提供理论基础的假说现在被最新的研究证实为是不能成立的。
However, this finding will probably not affect the use of finasteride for prostate cancer prevention, even though it undermines part of the rationale for its use, Dr. Godley commented to Medscape Oncology. \"I'm not sure that finasteride is being used much for that purpose anyway.\" In addition, the theory is a little different in each of these 2 trials, he pointed out. The current study set out to investigate whether high androgen levels increase the risk for prostate cancer, and showed that they do not, whereas the finasteride trial set out to determine whether lowering androgen levels reduces the risk for prostate cancer, and showed that it did.
然而，这一研究结果可能并不会影响非那雄胺用于预防前列腺癌，尽管它对非那雄胺的作用机理提出了质疑，Godley博士对《Medscape Oncology》杂志发表评论说。“不管怎样，我并不确定目前人们使用非那雄胺是否是为了预防前列腺癌。”而且，这两个实验的原理也有一些差异，他指出说。最新的这一实验是设计来研究是否高雄激素水平会增加前列腺癌的发病风险，结果是肯定的，而非那雄胺这一实验是设计来研究是否降低雄激素水平能降低前列腺癌的发病风险，其结果也是肯定的。
Neither the authors nor the editorialists have disclosed any relevant financial relationships.
研究者与社论作者均宣称与此研究无商业利益关联。
J Natl Cancer Inst. 2008;100:158-159, 170-183. |
发表于 2008-3-4 23:29:04