Looking to do a general blood cancer test.

Cancer runs in my family and I a young adult am looking to do a general cancer blood test to see if it picks up anything. The thing is, I do not know much about cencer screenings or their cost but I do know that cancer blood tests are not considered preventative. I tried to find out the cost but my doctor’s office claims not to know the cost or the codes that would be submitted to the insurance. I called my insurance company and the hospital lab that I usually do my blood tests at and neither of them know the costs as they both say that it would depend on what test and codes the doctor orders. The lab also mentioned that it would depend on what Cancer Antigen the doctor is looking for. Does anyone know the codes would be used for general cancer blood tests? I don’t need to know what specific type of cancer, I just want to know if I have cancer anywhere in my body. I would really appreciate any advice and feedback.

To anyone wondering I am planning on going to a new doctor soon, just not now due to other current medical issues.