Why are doctors so aprehensive in the order of doing a CEA trial for cancer?

Why are doctors so aprehensive in the order of doing a CEA trial for cancer?
CEA is a blood test that within certain instances can be immensely helpful but within others very confusing. One must be wary in using this testing as it is not perfect. It is neither sensitive nor specific. It is across the world used with our patients next to colon cancer. If a patient have colon cancer then we check this helpfulness. If elevated it is very cooperative to follow our patients for recurrence. If elevated, our patients sometimes hold surgery/chemotherapy. This should generally normalize. We consequently follow the CEA level every several months to monitor for an secondary elevation. If it becomes elevated again, it mostly means reverberation. We need to re-image and find it in a flash.
It should not be used as a screening test as it will miss masses cancers. Once again, it is not specific any.
I hope this helps...
Because CEA does not appear within all cancer, only a few. There is no overall theory test that can be given to detect all types of cancer. The CEA oral exam is best used as a tool to monitor a patient who they know have cancer. It's one way to give an account if the cancer is gone or still present in the body after treatment. It have been found devoted in monitoring patients near cancer of the rectum, lung, breast, liver, pancreas, stomach, and ovary.