LONDON (EGMN) –The daily, long-term use of low-dose aspirin cuts the risk of death from several types cancer, in addition to colorectal cancer, according to data published online Dec. 7 in the Lancet.

In a meta-analysis of eight randomized clinical trials involving 25,570 patients, low-dose aspirin taken for 5 years or longer reduced mortality from esophageal, pancreatic, brain, stomach, colorectal, prostate, and even lung cancer, with doses as low as 75 mg/day having an effect.

This is the first time that low-dose aspirin has been linked to a reduction in cancer mortality other than colorectal cancer, said Dr. Peter M. Rothwell, who conceived and coordinated the research.

Dr. Rothwell of the John Radcliffe Hospital and the University of Oxford, U.K., and his associates in October 2010 showed that low-dose aspirin reduced the 20-year risk of new colon cancer cases by approximately one-quarter and deaths by a third (Lancet 2010;376:1741-50).

The current study looked at all deaths from cancer that occurred during or after completion of eight randomized clinical trials that had been performed to look at the effects of daily aspirin vs. control for the primary or secondary prevention of vascular events (Lancet 2010 [doi:10.1016/S0140-6736(10)62110-1]).

Across all eight trials, 674 cancer deaths occurred in 25,570 patients, with aspirin treatment significantly reducing the risk of death, compared with no aspirin treatment (pooled odds ratio [OR] 0.79, 95% confidence interval [CI] 0.68-0.92, P = .003).

Using individual patient data available for seven of the trials and in which 657 cancer deaths occurred in 23,535 patients, the benefit of aspirin therapy was apparent only after 5 years or more of follow-up. The hazard ratio (HR) for death from all types of cancer was 0.66 (95% CI 0.50-0.87, P =.003), with a greater effect seen in patients with gastrointestinal tumors (HR 0.46, 95% CI 0.27-0.77, P =.003).

“We found that within the trials, while people were still on aspirin vs. no aspirin, the aspirin group had about a 30%-40% reduction in cancer deaths between year 5 and the end of the trial,” Dr. Rothwell said at a press briefing.

To determine the longer-term effects of aspirin on cancer mortality, the team looked more closely at data from three of the trials. These had all been conducted in the United Kingdom and continued to collect information on cancer deaths via national death certification and cancer registration systems long after the trials had concluded.

In all, individual patient data were obtained on 1,634 cancer deaths that had occurred in 12,659 patients. Aspirin was found to reduce the 20-year risk of death from all solid cancers by 20% (HR 0.80, 95% CI 0.72-0.88, P less than .0001). Again, the effect on gastrointestinal cancer was greater (HR 0.65, 95% CI 0.54-0.78, P less than .0001), but there was no effect on hematologic malignancies.

At least 5 years of therapy were needed to reduce the risk of death from esophageal, pancreatic, brain, or lung cancer, with 10 years or more treatment required to see any effect on stomach and colorectal cancer death rates, and 15 years or more for prostate cancer. With regard to both lung and esophageal cancer, the effect of aspirin was limited to adenocarcinomas.

While the findings do not mean that everyone over the age of 40 years should now suddenly start taking a daily dose of aspirin to prevent cancer, given the increased risk of bleeding in some individuals, “We should probably stop taking people off aspirin unless they’ve got side effects,” Dr. Rothwell said in an interview, adding “We probably shouldn’t discourage those who want to take aspirin as actively as we have been doing,” and perhaps physicians should “think about prescribing aspirin more in people at increased vascular risk, because they certainly benefit already.”

“There is a fundamental difference between the treatment and the prevention of a disease,” said Dr. Peter Elwood, professor of epidemiology at Cardiff University, Wales.

Dr. Elwood suggested that deciding to take a daily dose of aspirin to prevent cancer could be another choice patients make once they have all the relevant facts, much as lifestyle changes are advised but not prescribed for cardiovascular disease prevention.

The study was conducted independently of commercial interests. Dr. Rothwell has received honoraria from pharmaceutical companies with an interest in antiplatelet therapy, including AstraZeneca, Bayer, Boehringer Ingelheim, Sanofi-Aventis/BMS, and Servier. Dr. Elwood reported no relevant financial disclosures.

Copyright (c) 2010 Elsevier Global Medical News. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.

伦敦(EGMN)——据12月7日在线发表于《柳叶刀》(the Lancet)杂志的一项报告，在日常生活中长期应用低剂量阿司匹林可降低数种癌症的死亡风险。

此项荟萃分析共纳入8项随机临床试验(共计25,570例患者)，研究者对阿司匹林组患者和对照组患者之间的癌症死亡率进行了比较。在正式试验结束后，在充分调研相关资料(国家死亡证明和癌症登记制度)的基础上，研究者对其中3项研究(试验地点均在英国)的受试者死亡率进行了后续研究。

研究结果表明，服用低剂量阿司匹林 (服药时间≥5年，且剂量≥75 mg/d)可降低患者食管癌、胰腺癌、脑癌、胃癌、结肠癌、前列腺癌和肺癌的死亡率。8项研究中共有674例患者因癌症死亡，阿司匹林组患者癌症死亡风险较对照组显著降低[合并比值比(OR)为0.79，95%置信区间(CI)在0.68~0.92之间，P =0 .003]。对单个患者资料(仅7项研究有此数据)进行的评估表明，仅在使用阿司匹林时间超过5年(期间持续随访)的患者中才能观察到该效应，与对照组相比，阿司匹林组患者死于各种癌症的风险比(HR)为0.66(95%CI在0.50~0.87间，P =0.003)，该效应在胃肠道肿瘤患者中最为明显(HR=0.46，95%CI在0.27~0.77间，P =0.003)。后续研究共纳入12,659例患者，其中1,634例因癌症死亡。阿司匹林可使患者在20年中因实体瘤死亡的风险降低20%(HR=0.80，95%CI在0.72~0.88间，P＜0.0001)，该效应在胃肠道肿瘤中最为明显(HR=0.65，95%CI在0.54~0.78间，P＜0.0001)，但其对血液系统恶性肿瘤无效。

阿司匹林可使患者癌症风险降低30%~40%。但患者至少需服用阿司匹林5年才能降低其食管癌、胰腺癌、脑癌或肺癌的死亡风险，至少需要服药10年才能降低胃癌或结肠癌死亡风险，至少需15年才能降低前列腺癌死亡风险。阿司匹林对肺癌和食管癌的效应局限于腺癌。

既往研究表明，长期服用低剂量阿司匹林可使患者在20年中的结肠癌发病和死亡风险分别降低约1/4和1/3(Lancet 2010;376:1741-50)。而本研究首次发现阿司匹林还可降低其他癌症死亡风险。目前使用阿司匹林对癌症进行预防性治疗的前景尚不明确。

本研究无任何商业利益冲突。一位作者接受过多家制药公司的酬金。

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