How concerned should i be if one of the blood test for early cdt lung cancer came back slightly elevated? it was the mage 4. ct was clear

Don't worry: Screening tests are not perfect. The range of "normal" or "elevated" can be arbitrary. These tests are designed to be sensitive, which means that most people who have the disease will have a positive test, but if the marker is not specific enough for the disease, some people will have false positive tests. Normal chest ct is reassuring. Smoking cessation is always recommended to decrease risk.

There is no: Approved blood test for early detection of lung cancer. Ct's are approved for smokers and ex-smokers over 55. So, getting a blood test that scares you and then an expensive ct scan that is negative contributes to raising heath care costs and benefiting no one. Get a second opinion from a doctor that focuses on you, your benefit and not unproven expensive tests.