Answer to Ji Mou’s question | Does a negative tumor marker mean that there are no cancer cells in the body?

Patient Ji, who suffered from oral malignant tumor, underwent extended resection of tongue malignant tumor + mandibular block resection + left cervical lymph node dissection + adjacent flap transfer repair in the Department of Maxillofacial Surgery of the Oral Hospital on September 13, 2023. The pathology was: (left tongue root tumor) squamous cell carcinoma, tumors were visible in the "anterior boundary and lingual boundary" of the selective resection margin, and abnormal epithelial proliferation in the "posterior boundary and buccal boundary". Because of the positive resection margin, he went to the Department of Oncology for chemotherapy + immunotherapy.

Ji was confused and raised a point: "I checked my tumor markers and they are normal, which means there are no cancer cells in my body. Why do I need further treatment?"

So, is Ji’s point of view correct?

What is the relationship between tumor markers and cancer cells?

I believe that specialists are already very familiar with tumor markers. But for patients, as their general knowledge level increases and their participation in their own treatment increases, it is necessary to popularize the relationship between tumor markers and cancer cells .

1. What are tumor markers?

Tumor markers, also known as "tumor markers", academically usually refer to: a class of substances that reflect the existence and growth of tumors, including proteins, hormones, enzymes and oncogene products, which are produced by tumor cells themselves or by the body's response to tumor cells during the occurrence and proliferation of tumors.

In simple terms, tumor cells fight with you in your body. Whether they win or lose, they always leave some traces of war to show their existence. These "traces of war" are tumor markers.

2. Does an increase in tumor markers mean that you have cancer?

Of course not . For people without tumors, tumor markers may also increase slightly. For example: serum CA125 may increase during menstruation and early pregnancy; CEA may increase slightly during pregnancy, and AFP may also increase; cholestasis may cause CA199 to increase, etc.; abnormal liver and kidney function, bile duct obstruction and inflammatory infection can all cause tumor markers such as CEA, CYFRA21-1, SCC, ProGRP, etc. to increase in concentration. It depends on the specific situation.

3. Can normal tumor markers rule out cancer?

Of course not . Negative tumor markers cannot rule out related tumors. Tumor cells are difficult to detect in the early stages of the body. Only when tumor cells secrete protein molecules can they be detected in the blood. In addition, some cancer types do not secrete protein molecules, making them even more difficult to capture.

In summary, the detection of tumor markers is only for reference, and the diagnosis of the disease needs to be combined with relevant imaging or pathological examinations. So, tumor markers are like this for diagnosis and treatment.

For the patient Ji, the fact that a tumor was visible at the surgical margins indicated that there were definitely cancer cells in his body; it could be that his tumor burden was small, or that the cancer cells did not secrete protein molecules and were therefore not captured, so all blood tests for tumor markers were negative.

After discussion, Ji suddenly realized that the factor that determines whether he needs chemotherapy + immunotherapy after surgery is the stage of his tumor, not whether the tumor marker is positive.