Unfortunately, there aren't too many examples of that yet.

不幸的是在这方面还没有太多的例子
We don't know how to do that very well.

我们还不是很清楚怎么做好
We do know for prostate cancer

我们的确知道对于前列腺癌
and for certain other kinds of cancers there are molecules

以及其他一些特定的癌症
that you can detect in the blood.

在血液中可以发现某些分子
In prostate cancer there's a very particular molecule called

在前列腺癌中有个非常特别的分子
prostate specific antigen, PSA.

成为前列腺特异性抗原 PSA
If the levels of PSA rise in your blood,

如果在你血液中的PSA升高
that's a sign that there's something going wrong in your prostate

这是提示前列腺出问题的一个信号
and you get a more thorough exam.

你就得进行一个更加深入的测试
Blood tests are available

因此血液测试是可行的
but only for certain kinds of cancers

但只是对于某些特定的癌症