科学家们说，有一种新型血液检查常在患者表现出任何征兆或症状前就能检测出50多种癌症。专家们希望，当肿瘤仍处于易被医治或能被完全治愈的阶段时，这项检查可帮助医生们提前诊断出肿瘤的存在。

Doctors already have ways to screen for cancer, but a single blood test that could check for lots of different tumours simultaneously would be revolutionary. That's what researchers from the Dana-Farber Cancer Institute and Harvard Medical School, along with UK colleagues from the Francis Crick Institute and University College London, are working on.

医生已经有了筛查癌症的方法，但一项可同时检测出多种不同肿瘤的血液检查将是革命性的创新。这是丹娜法伯癌症研究所（Dana-Farber Cancer Institute）、哈佛医学院（Harvard Medical School）的研究人员，以及来自英国弗朗西斯·克里克研究所（Francis Crick Institute）及伦敦大学学院（University College London）的同事们正在进行的研究。

Their test looks for chemical changes to bits of genetic code that leak from tumours into the bloodstream. The patterns detected can predict whether a cancer is probably present and what type it is.

他们的测试寻找从肿瘤中泄漏到血流中的零星的遗传密码的化学变化。检测出的基因表达模式可预测人体内是否可能存在一种癌症，以及它是什么类型。

In trials with thousands of patients, the test was able to do this for more than 50 types of cancer, including lung and bowel, even when the person had no symptoms. It gave a correct positive result almost every time, but it did miss some cancers that were there, especially early ones.

在对数千名患者的测试中，即使受测者无任何症状，这项测试也能检测出超过50种癌症，包括肺癌和肠癌。测试几乎每次都给出了正确的阳性结果，但也确实漏掉了一些已存在于患者体内的癌症，特别是早期的癌症。

Experts say more studies are needed before the test can be rolled out for general use.

专家们表示，在这项测试可以被推广到普遍应用之前，仍需进行更多的研究。

词汇

screen 筛查，测试
blood test 血液检查
tumours 肿瘤
chemical changes 化学变化
genetic code 遗传密码
bloodstream 血流
patterns 模式
present 存在的
trials 试验
symptoms 症状
rolled out 被推广，被实行

阅读理解：请在读完上文后，回答下列问题 。

1. True or false? Currently, there aren’t ways to help doctors to test whether a patient has cancer.

2. What does the blood test look for in a patient?

3. In the trials, how many types of cancer was the test able to check for?

4. How accurate was the test during the trials?

答案

1. True or false? Currently, there aren’t ways to help doctors to test whether a patient has cancer.
False. Doctors already have ways to screen for cancer. 

2. What does the blood test look for in a patient? 
The blood test looks for chemical changes to bits of genetic code that leak from tumours into the bloodstream.

3. In the trials, how many types of cancer was the test able to check for?
The test was able to check for more than 50 types of cancer. 

4. How accurate was the test during the trials?
It gave a correct positive result almost every time, but it did miss some cancers that were there, especially early ones.