Not necessarily. Blood cancers, also called leukemias, result in high numbers of white blood cells. Acute leukemia can often be found on a routine blood test. However, not all blood cancers can be found this way. A diagnosis of blood cancer usually requires a history and physical exam in addition to blood tests. That's why it's important you see your doctor! there's more to the story than just a test.
Maybe. There are many kinds of blood cancers, not just leukemia, and they may not always be evident on a complete blood count, or cbc. Sometimes we see abnormal cells in the blood, which comfirms a leukemia, but that is not always the case. Diagnosing blood cancers requires history, physical exam, multiple blood tests and possibly bone marrow or lymph node biopsy. It's a complicated process.