About Tumor Markers
Ⅰ. The clinical significance of tumor markers
The clinical significance of tumor markers is as follows:
1. The early detection of tumors.
2. The diagnosis, differential diagnosis, and staging of tumors.
3. The census and screening of tumors.
4. To test the efficacy of surgery, chemotherapy, and radiotherapy for tumor patients.
5. An indicator of tumor recurrence.
6. The prognosis of the tumor.
7. To search for the primary tumor of metastatic tumors of unknown origin.
In short, tumor markers have important clinical significance in clinical practice, which can help tumor patients to find, diagnose and treat early.
Ⅱ. Results of tumor marker detection
How to read tumor marker test results?
(1) Normal reference value of alpha-fetoprotein (AFP): serum <25ug/L. Clinical significance:
1. The serum AFP of patients with primary hepatocellular carcinoma is significantly increased, and about 71% of the patients have AFP> 500ug/L.
2. Viral hepatitis and liver cirrhosis patients have different degrees of AFP increase, but the level is usually less than 500ug/L.
3. The serum AFP of patients with gonadal embryonal tumors can be increased.
4. After 3 months of pregnancy, serum AFP began to increase, and reached a peak at 7 to 8 months, generally below 400ug/L, and returned to normal 3 weeks after delivery. If maternal serum AFP is abnormally elevated, the possibility of fetal neural tube defect should be considered.
(2) Normal reference value of carcinoembryonic antigen (CEA): serum <5ug/L. Clinical significance:
1. Elevated serum CEA is mainly seen in colon cancer, rectal cancer, pancreatic cancer, gastric cancer, liver cancer, lung cancer, breast cancer, etc. Other malignant tumors also have different positive rates.
2. Continuous follow-up and detection of CEA. In general, the serum CEA concentration decreases when the condition improves and increases when the condition deteriorates.
3. Intestinal diverticulitis, rectal polyps, colitis, liver cirrhosis, hepatitis, and pulmonary disease increased in varying degrees, but the positive percentage was low.
4. The serum level of 98% of non-smoking healthy people is less than 5ug/L. About 39% of smokers have CEA>5ug/L.
(3) Normal reference value of prostate-specific antigen (PSA): <40ug/L. Clinical significance:
1. After prostate cancer surgery, the PSA concentration can gradually drop to normal. If the PSA concentration does not drop or rises again after surgery, tumor metastasis or recurrence should be considered.
2. For benign prostatic hypertrophy, prostatitis, kidney, and urogenital diseases, the serum PSA level can also increase, but it must be identified with other examinations.
3. About 5% of prostate cancer patients have elevated prostatic acid phosphatase (PAP), but PSA is at normal levels.
To sum up, although various markers have their clinical significance, a correct diagnosis can only be obtained through comprehensive analysis. Because there are many reasons for the increase of markers, not necessarily tumors, patients must not suspect that they have cancer when they see a slight increase in a certain index without the basis of pathological cytology diagnosis, causing an unnecessary psychological burden.
3. The meaning of tumor markers
The significance of tumor markers is that antigen markers are proteins produced by tumors that the body does not have or has less of. Such proteins can be detected in blood, and commonly used tumor markers include carcinoembryonic antigen, alpha-fetoprotein, prostate-specific antigen, and squamous cell carcinoma-specific antigen.
In the process of tumor growth, the carcinoembryonic antigen may be secreted, such as lung cancer, gastrointestinal tumors, pancreatic cancer, ovarian cancer, and other patients may be detected to have elevated carcinoembryonic antigen. Elevated squamous cell antigen may be detected in patients with squamous cell carcinoma, such as nasopharyngeal carcinoma of the head and neck, laryngeal carcinoma, and in patients with skin cancer.
Prostate cancer patients have a specific marker, namely PSA (prostate-specific antigen), which does not increase in other cancers, but only increases in prostate cancer, and PSA can reflect the growth and activity of prostate cancer cells. Such as patients with pre-cancerous prostate, cancer cells growing more active will be higher. When a patient's cancer cells are better suppressed after treatment, the PSA will drop to a lower level. Therefore, tumor markers are only proteins secreted by such tumors that can be detected in the body after suffering from tumors.
