Lancet ：阿司匹林可能在预防和治疗癌症中有效

3月21日，据英国广播公司报道，发表在英国医学杂志《柳叶刀》Lancet上的三项最新研究结果为阿司匹林的抗癌效果提供了有力的证据。

研究结果显示，每天服用少量阿司匹林可以预防癌症，甚至可以治疗癌症。

此前已经有许多人每天服用阿司匹林，以此来预防心脏病和中风的发生。

但是专家警告说，目前仍然没有充足的证据令医生向人们提出为了预防癌症而服用阿司匹林的建议。专家同时警告说，阿司匹林存在危险的副作用，包括引起胃出血。

最新的研究结果显示，每天服用低剂量(75至300毫克)阿司匹林能够在三年之内把癌症发病率减少四分之一。

与此同时，这样使用阿司匹林还能在五年之内把癌症引起的死亡率降低15%。

英国癌症研究会的约翰逊教授说，新的研究结果令人兴奋，但是他仍然认为人们在服用阿司匹林的时候应该同医生商量，因为这种药物存在着可能的副作用。

另外一项研究：英国医学研究委员会（MRC）参与的一项国际合作新研究发现，有家族癌症病史者若长期服用阿司匹林达5年以上，其罹患癌症机率可显着降低约60%。
     过去已知阿司匹林能降低癌症风险，相关研究也有近20年的历史，然而此次新研究首次以随机对照试验（randomised controlled trial）证实阿司匹林在这方面的疗效。新研究于1999年至2005年间追踪861名有“林奇式症候群”者（Lynch syndrome）──与遗传性基因有关的癌症高危险群，其中一部分连续2年每天服用2片600mg阿司匹林，另一部分则仅服用安慰剂。2007年时两组研究对象的癌症罹患率相去不远，但到2010年时，服用安慰剂的研究对象罹患结肠癌的比例比另一组高了将近2倍。研究成果显示，连续服用阿司匹林两年以上会有较明显的成效：安慰剂组23人罹患大肠癌；阿司匹林组只有10人。整体而言，服用安慰剂者中大约30%后来发展出林奇式症候群相关之癌症，服用阿斯匹灵者的罹患率则相对只有15%。
      研究人员解释，虽然一般视息肉为癌症发展前的症兆，两组研究对象中长息肉的人数却相差不大，唯独服用阿司匹林者较少有人因息肉生长而转发为癌症。过去的随机对照试验因为实验追踪期不够长，以致未能成功证实阿司匹林的防癌功效。
      大肠癌高居英国癌症死因第二位，每年夺走1万6千条生命。虽然新研究证实阿司匹林有降低癌症风险的效用，但其副作用则会引发胃酸过度分泌而造成胃溃疡，有强烈家族癌症遗传病史者会许可藉由市面上随手可得的制酸剂解决此问题，然无论如何，科学家建议任何人在请示医生前都不应冒然开始天天服用阿司匹林。

链接：http://health.msn.com/health-top ... might-combat-cancer

http://www.medicinenet.com/script/main/art.asp?articlekey=156184

Effect of daily aspirin on risk of cancer metastasis: a study of incident cancers during randomised controlled trials

Prof Peter M Rothwell FMedSci a , Michelle Wilson MSc a, Jacqueline F Price MD b, Prof Jill FF Belch MD c, Prof Tom W Meade FRS d, Ziyah Mehta PhD a

Background Daily aspirin reduces the long-term incidence of some adenocarcinomas, but effects on mortality due to some cancers appear after only a few years, suggesting that it might also reduce growth or metastasis. We established the frequency of distant metastasis in patients who developed cancer during trials of daily aspirin versus control. Methods Our analysis included all five large randomised trials of daily aspirin (≥75 mg daily) versus control for the prevention of vascular events in the UK. Electronic and paper records were reviewed for all patients with incident cancer. The effect of aspirin on risk of metastases at presentation or on subsequent follow-up (including post-trial follow-up of in-trial cancers) was stratified by tumour histology (adenocarcinoma vs other) and clinical characteristics. Findings Of 17 285 trial participants, 987 had a new solid cancer diagnosed during mean in-trial follow-up of 6·5 years (SD 2·0). Allocation to aspirin reduced risk of cancer with distant metastasis (all cancers, hazard ratio [HR] 0·64, 95% CI 0·48—0·84, p=0·001; adenocarcinoma, HR 0·54, 95% CI 0·38—0·77, p=0·0007; other solid cancers, HR 0·82, 95% CI 0·53—1·28, p=0·39), due mainly to a reduction in proportion of adenocarcinomas that had metastatic versus local disease (odds ratio 0·52, 95% CI 0·35—0·75, p=0·0006). Aspirin reduced risk of adenocarcinoma with metastasis at initial diagnosis (HR 0·69, 95% CI 0·50—0·95, p=0·02) and risk of metastasis on subsequent follow-up in patients without metastasis initially (HR 0·45, 95% CI 0·28—0·72, p=0·0009), particularly in patients with colorectal cancer (HR 0·26, 95% CI 0·11—0·57, p=0·0008) and in patients who remained on trial treatment up to or after diagnosis (HR 0·31, 95% CI 0·15—0·62, p=0·0009). Allocation to aspirin reduced death due to cancer in patients who developed adenocarcinoma, particularly in those without metastasis at diagnosis (HR 0·50, 95% CI 0·34—0·74, p=0·0006). Consequently, aspirin reduced the overall risk of fatal adenocarcinoma in the trial populations (HR 0·65, 95% CI 0·53—0·82, p=0·0002), but not the risk of other fatal cancers (HR 1·06, 95% CI 0·84—1·32, p=0·64; difference, p=0·003). Effects were independent of age and sex, but absolute benefit was greatest in smokers. A low-dose, slow-release formulation of aspirin designed to inhibit platelets but to have little systemic bioavailability was as effective as higher doses. Interpretation That aspirin prevents distant metastasis could account for the early reduction in cancer deaths in trials of daily aspirin versus control. This finding suggests that aspirin might help in treatment of some cancers and provides proof of principle for pharmacological intervention specifically to prevent distant metastasis.

癌症始终不能根治。真希望早日有这样的新药被研发出来。

学习，谢谢。

之前确实看到过好多文章提到过，应该还有相关的系统评价呢！