VOA标准英语2011--Urine Test May Improve Prostate Cancer D

Urine Test May Improve Prostate Cancer Diagnosis¹

Scientists have developed a new test for prostate cancer that may help patients and their doctors make difficult treatment decisions. But identifying the most aggressive and dangerous prostate cancers still won't be easy.
A widely-used blood test is often used to screen for potential prostate cancer, but University of Michigan researcher Scott Tomlins says it has its limitations.
"The PSA test, prostate-specific antigen, is just that - it's very specific for prostate tissue, but it's not specific for prostate cancer."
Men with a PSA score that is high or increasing may have prostate cancer. But the PSA result could also mean an enlarged but non-cancerous prostate gland².
So doctors often recommend a needle biopsy of the prostate. The procedure can be unpleasant, and worse, it often doesn't provide definitive³ guidance on whether or how to treat the patient.
So Tomlins and his colleagues are evaluating a new test that would identify a genetic⁵ anomaly that is linked to cancer.
"And what it does is," Tomlins says," it puts two genes⁶ together - TMPRSS2 and ERG - that sort of function as an 'on' switch in the prostate, that's what TMPRSS2 does, and then ERG is a gene⁴ that cause cells to become cancerous. And so you basically turned on a bad gene in the prostate."
Tomlins says this particular gene pair is unique to prostate cancer - it doesn't show up in normal prostate tissue, and it isn't found in other cancers. But it doesn't occur in all patients.
In this new study, the researchers tested the urine of prostate patients for TMPRSS2:ERG plus PCA3, another genetic marker associated with prostate cancer.
The men in the study had suspicious PSA levels and had been referred for a needle biopsy.
Researchers found that the urine test helped predict whether the high PSA score was caused by cancer, and also helped predict how aggressive the cancer was.
But Tomlins says that, although the new test can help doctors make a diagnosis and guide treatment, it has its limitations.
"I think the idea that you'll have a test that is 100 percent specific for cancer, it's 100 percent sensitive, and it will only identify the type of cancer that's aggressive and needs to be treated - I think that we are very far away from that, and I don't know if we'll ever be able to do that."

1 diagnosis   

n.诊断，诊断结果，调查分析，判断

参考例句：

• His symptoms gave no obvious pointer to a possible diagnosis.他的症状无法作出明确的诊断。
• The engineer made a complete diagnosis of the bridge's collapse.工程师对桥的倒塌做一次彻底的调查分析。

2 gland   

n.腺体，(机)密封压盖，填料盖

参考例句：

• This is a snake's poison gland.这就是蛇的毒腺。
• Her mother has an underactive adrenal gland.她的母亲肾上腺机能不全。

3 definitive   

adj.确切的，权威性的；最后的，决定性的

参考例句：

• This book is the definitive guide to world cuisine.这本书是世界美食的权威指南。
• No one has come up with a definitive answer as to why this should be so.至于为什么该这样，还没有人给出明确的答复。

4 gene   

n.遗传因子，基因

参考例句：

• A single gene may have many effects.单一基因可能具有很多种效应。
• The targeting of gene therapy has been paid close attention.其中基因治疗的靶向性是值得密切关注的问题之一。

5 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。

6 genes   

n.基因( gene的名词复数 )

参考例句：

• You have good genes from your parents, so you should live a long time. 你从父母那儿获得优良的基因，所以能够活得很长。 来自《简明英汉词典》
• Differences will help to reveal the functions of the genes. 它们间的差异将会帮助我们揭开基因多种功能。 来自英汉非文学 - 生命科学 - 生物技术的世纪