VOA常速英语2016--灵敏检测前列腺癌或有历史性进展（在线收听）

灵敏检测前列腺癌或有历史性进展

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.

科学家研发了一种检测前列腺癌的新方法，或将帮助病人及其主治医生做出以往不容易做的治疗决定。但识别出最具有破坏性和危险性的前列腺癌，依然不是一件容易事。

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.

人们普遍使用血液测试来检测前列腺癌的可能性，但密歇根大学的斯科特表示，血液检测也有其局限性。

"The PSA test, prostate-specific antigen, is just that - it's very specific for prostate tissue, but it's not specific for prostate cancer."

 “前列腺特异性抗原（PSA）的特点是，它对前列腺组织有特异性，但对前列腺癌并无特异性。”

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 gland. 

PSA较高或者不断上升的男子可能患有前列腺癌。但也有可能是前列腺增生，而非前列腺癌。

So doctors often recommend a needle biopsy of the prostate. The procedure can be unpleasant, and worse, it often doesn't provide definitive guidance on whether or how to treat the patient.

因此一些医生建议做一个前列腺穿刺活检。但穿刺活检的操作步骤可能不让人舒心，甚至是糟心，因为对于病人是否需要做穿刺活检以及如何做穿刺活检，并没有明确的指导。

So Tomlins and his colleagues are evaluating a new test that would identify a genetic anomaly that is linked to cancer. 

斯科特及其同事正在评估一项新的检测，该检测能识别与癌症有关的遗传性异常。

"And what it does is," Tomlins says," it puts two genes 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 gene that cause cells to become cancerous. And so you basically turned on a bad gene in the prostate."

 “这项检测是将两个基因TMPRSS2和ERG放在一起，前者的作用相当于前列腺的开关，而后者能引起细胞癌变。而患有前列腺癌的病人基因变异到ERG坏的基因那边。

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.

斯科特表示，只有患有前列腺癌的病人才会有这个特殊的基因对——正常的前列腺组织以及其他癌症患者的身上是没有的。

In this new study, the researchers tested the urine of prostate patients for TMPRSS2:ERG plus PCA3, another genetic marker associated with prostate cancer. 

也并不是所有患者身上都有这个基因对。在这项新研究中，斯科特等人检测了前列腺癌患者尿液中的TMPRSS2:ERG和PCA3。

The men in the study had suspicious PSA levels and had been referred for a needle biopsy. 

PCA3是与前列腺癌有关的另一遗传标记。该患者PSA含量可疑，并被建议做穿刺。

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.

他们发现，尿检帮助预测PSA含量过高是否由癌症引起，并能帮助预测癌症的严重程度。

But Tomlins says that, although the new test can help doctors make a diagnosis and guide treatment, it has its limitations.

但斯科特说，虽然新检测能帮助医生做出诊断，指导治疗，但仍有其局限性。

"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."

 “我认为，要实现具有100%前列腺癌特异性、100%灵敏度的检测，识别出需要治疗的前列腺癌的这一步，离我们还很遥远。我不确定我们是否能实现这一点”。