Prostate cancer tumor markers

Prostate cancer is a common malignant tumor of the male urinary system, accounting for 10% to 20% of all types of cancer in men. With the improvement of living standards, the intensification of environmental pollution and changes in dietary structure, the incidence of prostate cancer in Chinese men is increasing.

Before the 1980s, the clinical diagnosis of prostate cancer was based on the patient's clinical symptoms and signs, anal indicators, B-ultrasound, and even invasive methods such as tissue biopsy. However, the diagnostic sensitivity was low and the misdiagnosis rate was high. Since the late 1980s, the use of radioimmunoassay to measure serum prostate-specific antigen has brought the diagnosis of prostate cancer into a new stage.

Prostate antigen-specific antigen is an antigen related to prostate cancer and is recognized as the most meaningful tumor marker for early diagnosis of prostate cancer. Prostate antigen (pSA) is a single-chain glycoprotein mainly secreted by prostate epithelial cells, which can stimulate prostate cancer cells to produce reactive oxygen and has immunomodulatory effects. pSA exists in the blood in two forms: free and bound. Among them, free prostate specific antigen (f-pSA) accounts for only a small part, and the bound form accounts for the majority, which is combined into pSA-ACT complex, pSA-macroglobulin and pSA-C protein inhibitor.

Serum prostate-specific antigen (pSA) is an organ-specific antigen and does not have tumor specificity. It can be slightly elevated in benign prostatic hyperplasia, prostatic polyps, prostatic ischemia, bacterial prostatitis, etc. Especially when pSA levels increase from low levels, the pSA values ​​of prostatic hyperplasia and prostate cancer overlap a lot, and pSA cannot be used as an absolute indicator for diagnosing the presence or absence of malignant prostate disease. Free prostate antigen alone is not unique to prostate cancer, so it is also difficult to use it as a basis for differential diagnosis. Therefore, it is necessary to rely on a comprehensive judgment of the development and changes of the two dynamic levels, that is, to detect the level of free pSA and calculate the percentage of pSA in f-pSA.

Prostate cancer poses a great threat to humans. It is prone to recurrence after surgery and has poor treatment effects. With the in-depth study of pSA, the problem of its treatment has begun to be solved from the molecular immunology level, such as using radioactive isotope-labeled anti-pSA monoclonal antibodies to treat prostate cancer, encoding pSA mRNA to enable activated lymphocytes to kill prostate cancer cells that secrete pSA, and integrating modified pSA genes into viruses to make vaccine-infected animal models. I believe that with the continuous development of medicine, early diagnosis, early prevention, and non-invasive and painless complete cure of prostate cancer will be possible.