Re: Does any cancer's show up in a blood test?
Some cancers do have blood tests that can indicate a problem (such as the PSA for prostate cancer) but many cannot be diagnosed by bloodwork. Cancers that affect the blood could show up as abnormalities on routine bloodwork, but other than that, special tests need to be run. I'm not sure what tests the doctor is running, but there is no specific blood test for stomach cancer. The best way to diagnose that is with endoscopy, where they can see the inside of the stomach. If the blood tests don't show anything and you are still having symptoms, there are some other diagnostic tests (barium x-ray, endoscopy, etc) that may be ordered. But blood tests are the least invasive and least expensive, so they are usually the place to start trying to find the problem.