VOA英语2010年-Researchers Develop More Effective Prostate

In many countries, prostate cancer is among the leading causes of cancer deaths in men. Doctors rely on a blood test called PSA (prostate-specific antigen) to screen for the disease. But there are big problems with the PSA test. Now, the researchers in Iceland report having a genetic¹ tweak that will make PSA results a much better indicator² of prostate cancer.

Prostate cancer can develop even when PSA scores are in the normal range. Likewise, men with high PSA levels can be completely free of disease. Genetics researcher Kári Stefánsson says the problem is that there's really no such thing as a "normal" PSA level that applies to all men.

"Among normal men - men without any disease in their prostate - there is considerable difference in how high their normal PSA level is. And we managed to find genetic markers that allow us to classify men into those who normally have high PSA, and those who have normally low PSA."

Stefánsson is the CEO of deCODE³ Genetics, in Iceland, and was earlier on the medical school faculties⁴ of the University of Chicago and Harvard. He says adding genetic information to the PSA score personalizes the prostate cancer test.

"So you may actually be a man who was born with naturally very low PSA, and you could actually double your PSA level because you have cancer, and it would still be read as normal. So what we have now is a test that allows us to control for all of this."

Stefánsson and his colleagues describe the new genetic supplement to the PSA test in the journal Science Translational Medicine.

For their study, they used genetic samples from about 2,500 men in Iceland and Britain. Iceland's population is famously homogeneous, and the British component⁵ was mostly men of European descent, which raises the question of how reliable the results would be for men of other ethnic⁶ groups. Stefánsson acknowledges the issue.

"Most of the drugs on the market today have been developed by doing clinical trials in people of European descent. So there is always a bit of a concern that some of them may work less well for people of other ethnic backgrounds, and the same thing applies to diagnostic instruments."

That may be especially true for Africans and men of African descent, he said, because they have higher rates of prostate cancer and die more often of the disease.

Kári Stefánsson of deCODE Genetics says the genetic supplement to the PSA test could be on the market as soon as next year.

1 genetic   

adj.遗传的，遗传学的

参考例句：

• It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
• Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。

2 indicator   

n.指标；指示物，指示者；指示器

参考例句：

• Gold prices are often seen as an indicator of inflation.黃金价格常常被看作是通货膨胀的指标。
• His left-hand indicator is flashing.他左手边的转向灯正在闪亮。

3 decode   

vt.译（码），解（码）

参考例句：

• All he had to do was decode it and pass it over.他需要做的就是将它破译然后转给他人。
• The secret documents were intercepted and decoded.机密文件遭截获并被破译。

4 faculties   

n.能力( faculty的名词复数 )；全体教职员；技巧；院

参考例句：

• Although he's ninety, his mental faculties remain unimpaired. 他虽年届九旬，但头脑仍然清晰。
• All your faculties have come into play in your work. 在你的工作中，你的全部才能已起到了作用。 来自《简明英汉词典》

5 component   

n.组成部分，成分，元件；adj.组成的，合成的

参考例句：

• Each component is carefully checked before assembly.每个零件在装配前都经过仔细检查。
• Blade and handle are the component parts of a knife.刀身和刀柄是一把刀的组成部分。

6 ethnic   

adj.人种的，种族的，异教徒的

参考例句：

• This music would sound more ethnic if you played it in steel drums.如果你用钢鼓演奏，这首乐曲将更具民族特色。
• The plan is likely only to aggravate ethnic frictions.这一方案很有可能只会加剧种族冲突。