Would blood test be able to find testicular cancer before you can feel it?

It usually does not: Work this way. There is no indication to get these tests unless a mass is suspected, in the testes or a midline abnormality most commonly in a young man. The blood tests, Alpha feto protein and human Chorionic Gonadotropin are indicated to help point the origin of a testis or mediastinal mass. The disease is unusual enough to make these test as routine screening not worthwhile.

Sometimes: Some types of testicular cancers produce substances that circulate in the blood and can be detected with simple blood tests. Not all do, however, and one would usually not do a blood test if there was no mass or abnormality in the testicles.

May be: Some testicular cancers are associated with elevated blood levels of Alpha feto protein and hcg. However, unless one is suspecting testicular cancer, there is no routine reason to do these tests.