阿司匹林讓人吃驚的另一面

Science and Technology Prevention of cancer Wonder drug
科技 預防癌症 特效藥

Aspirin continues to amaze
阿司匹林讓人吃驚的另一面

FOR thousands of years aspirin has been humanity's wonder drug.
幾千年來，阿司匹林就一直是人類的特效藥。

Extracts from the willow tree have been used for pain relief in folk medicine since the time of the ancient Greeks.
從古希臘開始，在民間醫藥中，人們就用柳樹的萃取物緩解疼痛。

By 1897 a synthetic derivative (acetyl salicylic acid) of the plant's active ingredient (salicin) was created. This allowed aspirin to become the most widely used medicine in the world.
1897年，這種植物中的有效成分的人工合成衍生物誕生了，於是阿司匹林變成了世界上應用最廣泛的藥品。

In recent years its benefits as a blood-thinning drug have led to it being prescribed in low doses of around 50mg to reduce deaths from stroke and heart attack.
最近幾年，由於阿司匹林的防血凝功能，在用其治療中風和心臟病的時候，劑量很小，維持在50mg的水平左右。

There were also hints that aspirin may help prevent some cancers.
也有跡象表明阿司匹林可以幫助預防一些癌症。

But these were mostly based on observational studies, which can be misleading.
不過這些結論大多都是在觀察研究的基礎上的，因而有可能產生誤導。

The gold standard of scientific evidence is the randomised controlled trial, preferably one with a lot of people and held over a long time.
國際上科學證據的標準是由隨機對照實驗得出的結果，尤其是那些有很多人蔘與又經過很長時間的實驗。

The results of just such a trial, published in the Lancet, suggest that aspirin is indeed an astonishing drug.
而就是這樣一份發表在《柳葉刀》上的論文表示阿司匹林的確是一種讓人吃驚的藥物。

Peter Rothwell at the John Radcliffe Hospital in Oxford and his colleagues looked at deaths due to cancers during and after randomised trials of daily aspirin.
來自牛津的約翰·拉德克里夫醫院的彼得·羅思韋爾（Peter Rothwell）和他的同事們研究了在每日服用阿司匹林的隨機對照實驗期間或者之後因癌症而死亡的病例。

The trials had actually been started to look at how useful aspirin was for preventing heart attacks and strokes. Nevertheless, the data from the 25,570 patients enrolled in eight trials was also revealing about cancer.
這一實驗本是爲了研究阿司匹林在防止心臟病和中風方面的療效的，然而八項試驗25570名患者的數據也揭示了阿司匹林對於癌症的療效。

In trials lasting between four and eight years, the patients who had been given aspirin were 21% less likely to die from cancer than those who had been given a placebo.
在那些歷時4到8年之間的實驗中，服用阿司匹林的患者因癌症而死亡的概率比那些服用安慰劑的患者小了21%。

These results were based on 674 cancer deaths, so are unlikely to represent the kind of statistical oddity that can beset studies on cancer risks that sometimes create headlines.
這些結果是在674例癌症死亡病例的基礎上得出的，所以不大可能是所謂的統計學上的例外。對癌症風險的研究會因這種例外而受挫，有時甚至會鬧成大新聞。The benefits of aspirin were also apparent many years after the trials had ended.
試驗結束後的很多年後，阿司匹林的效果也仍舊明顯。

After five years, death rates for all cancers fell by 35% and for gastrointestinal cancers by 54%.
五年後，所有癌症的死亡率下降了35%，而胃腸道癌症的死亡率則下降了54%。

A long-term follow-up of patients showed that the 20-year risk of cancer death remained 20% lower in those who had taken aspirin.
一項長期的病情跟蹤報告顯示，那些服用阿司匹林的患者的20年內的癌症死亡風險比那些不服用的低了20%。

The study revealed that the effect takes time to accrue, so aspirin must be taken over a long period.
這項研究揭示了阿司匹林的效果是隨着時間而遞增的，所以必須長期服用才行。

The latent period for improving oesophageal, pancreatic, brain and lung cancer was about five years of aspirin taking on a daily stomach and colorectal cancer the effects took ten years and for prostate cancer about 15 years.
每日服用阿司匹林對改善食管癌，胰腺癌，腦癌和肺癌的潛伏期爲5年，對胃癌和結直腸癌則要花10年才能起作用，而前列腺癌則要15年。

The means by which aspirin prevents cancer is not well understood.
這意味着目前還不清楚阿司匹林到底是怎麼預防癌症的。

It is believed that it inhibits an enzyme that promotes cell proliferation in tumours.
研究人員認爲阿司匹林阻礙了一種在腫瘤內部促進細胞增殖的酶的活動。

The researchers also found that small daily doses of aspirin were enough, and that taking more than 75mg conferred no additional benefits.
研究者還發現，每天服用小劑量的阿司匹林就已足夠，劑量超過75mg後不會再增加效果。

Those starting on aspirin in their late 40s or 50s benefit most.
那些從四五十歲末就開始服用阿司匹林的人得到的效果最好。

Current guidelines on using aspirin for reducing the chances of a stroke or heart attack rightly warn of the small risk of ulcers and of dangerous bleeding in the stomach.
目前在用阿司匹林治療中風或者心臟病時，用藥說明上會明確提醒有可能出現潰瘍和危險性胃出血。

These guidelines will probably have to be revised given the new findings.
而鑑於這些新發現，這些說明很可能將要被修改了。

However, it remains unlikely that popping aspirin will be recommended for everyone like a vitamin supplement.
不過阿司匹林泡騰片不大可能像維生素補充劑一樣被推廣至每一個人。

Aspirin is a highly cost-effective treatment: taking it for five to ten years easily beats initiatives to screen for breast and prostate cancers.
服用阿司匹林是一種非常划算的治療：只要吃五到十年，就能打敗那些讓你做乳腺癌或者前列腺癌掃描的建議。

To put it another way, ask yourself what a pharmaceuticals firm might charge for a drug that would reduce the chance of death by cancer by 20%—and then note that 100 days' supply of low-dose aspirin can cost less than a dollar.
換種說法，問問你自己，什麼樣的醫藥公司在看到100天的小劑量阿司匹林供應量還值不到一美元時，會對這種能夠減少20%癌症死亡機率的藥品開價呢？

By anyone's measure, that is a bargain.
不管按照哪一方的標準，這都是一筆非常划算的交易。