Normal tumor markers do not rule out cancer.
Elevated tumor markers do not necessarily mean that there is cancer, and similarly normal tumor markers cannot rule out that there is no cancer. Tumor markers are a means of screening for tumors, but after all, they are only used as a reference, and at the same time, it depends on the value of the test, if it is just a little bit higher, then basically it is not significant.
If it is much higher than the reference value, then the doctor will carry out further examination according to this corresponding marker, so it is just a reference. Similarly, if the patient has clinical symptoms, but the tumor marker is normal, then the test result of the tumor marker can not be used as a reference, but needs to be diagnosed through imaging, pathological examination and other comprehensive diagnosis.
For example, in the clinic, common colorectal cancer and liver cancer, these tumor markers often show normal, so tumor markers are only a reference, not a diagnostic basis.
Normal tumor markers can not exclude cancer, but should be analyzed together with medical history and clinical symptoms.