Can a routine blood test show abnormalities due to cancer?

Misinformed?: Cancer is not one monolithic entity. The are hundreds of forms of cancers. Every organ gas a variety of possible cancers as do the various blood cells and other tissues in the body. There is no routine cancer test.

It depends...: If we are talking of the specific cancer type: leukaemia or lymphoma (depending on the type) than, yes, these cancers can be detected in routine blood test. Cancers of solid organs do not present as abnormality in the routine blood test.However, certain changes (anemia) can trigger a search for possible cause, bleeding from colon cancer, for example.