What is the clinical significance of prostatespecific antigen (PSA) and free-PSA? PSA is a prostate-specific antigen, which is synthesized and secreted by prostate epithelial cells into the seminal fluid. There are two molecular forms of serum PSA: bound PSA and f-PSA. PSA is a specific marker for prostate cancer and is one of the few organ-specific tumor markers available. PSA can be used as an important indicator to monitor changes in prostate cancer disease and its outcome. Total PSA (t-PSA) and f-PSA levels are also seen to be mildly elevated in patients with prostate hypertrophy, prostatitis, renal and genitourinary disorders and must be differentiated in conjunction with other tests. Some patients with breast cancer also show; B varying degrees of PSA positivity. Special attention should be paid to the fact that prostate massage, if performed before collecting the patient’s serum specimen, will result in elevated serum PSA. 12.What is the clinical significance of neuron-specific enolase (NSE)? Enolase is the enzyme that catalyzes the final breakdown of glycerol in the glycogenolysis pathway. It consists of 3 independent gene fragments encoding 3 subunits with different immunological properties αβγ, which make up 5 forms of the isoenzyme αα, ββ, γγ, αγ, βγ. Dimer is the active form of the enzyme molecule, and the γ subunit isoenzyme is present in neurons and neuroendocrine tissues and is called NSE. The molecular mass of NSE is 78ku. Patients with small cell lung cancer (SCLC) have significantly higher levels of NSE than Patients with non-small cell lung cancer such as lung adenocarcinoma, lung phosphor carcinoma, large cell lung cancer, etc. It can be used for differential diagnosis and monitoring the therapeutic effect of small cell lung cancer after radiotherapy and chemotherapy. The concentration of NSE gradually decreases to normal level when the treatment is effective, and the serum NSE level increases when recurrence occurs. NSE is abnormally elevated in patients with renal neuroblastoma, but not in wilms tumor. Therefore, NSE can be used as a differential diagnosis between neuroblastoma and wilms tumor, and can also be used to monitor changes in neuroblastoma, evaluate the efficacy of treatment and predict recurrence. Serum NSE can also be increased in patients with neuroendocrine tumors, such as pheochromocytoma, islet cell tumor, medullary thyroid carcinoma, melanoma, and retinoblastoma. However, it should be noted that NSE is also present in normal red blood cells, and hemolysis of the specimen will affect the measurement results. 13.What is the clinical significance of human chorionic gonadotropin (hCG, β-HCG)? hCG is a type of glycoprotein hormone secreted by placental trophoblast cells. The concentration of hCG can be increased in blood and urine: in women with normal pregnancy, in non-neoplastic states such as endometriosis and ovarian cysts, in endometrial cancer, staphyloma, chorioepithelial carcinoma, breast cancer, testicular cancer, and ovarian cancer. Studies have shown that hCG can be high in some primary liver, gastric, and colorectal cancers that are negative for both AFP and GGT. Some non-trophoblastic tumors such as lung cancer and bladder cancer are also seen to be increased. 14.What is the clinical significance of growth hormone? Humangrowth hormone (HGH) is a protein secreted by alpha cells of the pituitary gland (anterior pituitary gland) with a molecular mass of about 21.5 ku. Under normal conditions, HGH is secreted in a pulsatile manner and is regulated by growth hormone-releasing hormone produced by the hypothalamus, and is also influenced by gender, age and circadian rhythm. HGH secretion generally reaches its highest point around the age of 20 and decreases by 14% every l0 years thereafter. It promotes protein synthesis, accelerates the growth of body tissues with growth capacity, stimulates the growth of long bones and various tissues and organs, and promotes lipolysis, inhibits glucose utilization and increases blood sugar. Increased secretion of HGH can be seen in: starvation, malnutrition, hypoglycemia, stress, exercise, etc.; acromegaly, gigantism, etc.; application of certain drugs such as hormones, insulin, arginine, etc.; chronic liver disease, liver cirrhosis; pituitary tumors and tumors of kidney, lung and other organs. Reduced HGH secretion can be seen in: pituitary dwarfism, hypopituitarism, obesity and excessive lysergic mood. 15.What is the clinical significance of Ferritin (Fe)? Richter et al. isolated the glycoprotein from malignant tumor cell lines. Molecular mass is 450ku. Increase can be seen in: leukemia, primary liver cancer, breast cancer, lung cancer, aplastic anemia and refractory anemia, liver disease, myocardial infarction, etc. Decrease can be seen in: iron deficiency anemia, pregnancy, lactation, malnutrition, etc. 16.Can tumor markers be used as physical examination items? Early detection and diagnosis is the key to cure tumor or even prevent tumor. Physical examination is an important way to detect cancer and precancerous lesions at an early stage. Blood test indicators, ultrasound, X-ray, anorectal examination, Pap smear and mammogram in gynecological examination are all common methods to screen tumors. Blood test is an important means to detect early cancer in physical examination. Testing whether the indicators of various tumor markers in blood are elevated can help to detect and identify various malignant tumors. It is a long process from normal cells to tumor cells and precancerous lesions. Early detection of abnormal tumor-related tumor markers can prevent normal cells from becoming cancerous or benign tumor cells from becoming malignant by taking timely and effective preventive or therapeutic measures, thus preventing the occurrence of tumors, especially malignant tumors, and improving the cure rate of tumors. Under the situation that cancer-causing factors are increasing and the degree of environmental pollution is unknowable and uncontrollable, it is necessary to take tumor marker test as a medical checkup item. It is also a wise choice. 17.What are the circumstances under which tumor markers should be checked in time? Any kind of disease always shows certain signals before the onset. The following are the 8 early signs of cancer proposed by the World Health Organization: (1) palpable hard nodes or hard changes, such as those found in the breast, skin and tongue; (2) obvious changes in warts (verrucas) or moles; (3) persistent abnormal digestion; (4) persistent hoarseness, dry cough and difficulty in swallowing; (5) abnormal heavy bleeding of menstruation, bleeding outside of menstrual period; (6) unexplained bleeding from nose, ear, bladder or intestines; (7) unexplained bleeding from the nose, ear, bladder or intestines; (8) unexplained bleeding from the nose, ear, bladder or intestines. (6) Unexplained bleeding; (7) Wounds that do not heal, swelling that does not go away; (8) Unexplained weight loss. If you find any suspicious signs, you should not take it lightly. You should go to the hospital in time for consultation and necessary examination to avoid delaying the disease and causing lifelong regret. 18.What are the benefits of joint examination of multiple tumor markers? Tumor is the result of multiple cloning of single mutated cells, and its occurrence is a multi-step and multi-gene cancer process. The biological characteristics of tumor cells are complex and polymorphic, which are manifested by the differences of different pathological types of tumors after carcinogenesis, the heterogeneity of tumor cells of the same pathological type, and the differences of tumor cell genotype Lang cell phenotype. Cells with different characteristics exist in a tumor, which may differ in growth rate, surface receptors, immune characteristics, infiltration, metastasis, and toxicity to drugs. Therefore, the same tumor may contain one or more tumor markers, while different tumors or different tissue types of the same tumor may have both common and different tumor markers. In order to improve the positive rate of tumor marker detection, some tumor markers with higher specificity are selected for joint detection, which can improve the application value of tumor markers. 19.What other tests should be done for positive tumor markers? For patients with high suspicion of tumor, a positive result of tumor marker test provides a basis for tumor diagnosis, and then other tests including ultrasound, MRI, CT, X-ray and infrared breast examination can be used to further confirm the diagnosis, which can achieve the purpose of early detection and early treatment. For those who have no prior signs of cancer but only found positive tumor markers in routine physical examination, first of all, it is still necessary to further examine the corresponding organs, including ultrasound, MRI, CT, X-ray, infrared mammography, etc. For example, if CA242 is positive, focus on gastroscopy, abdominal ultrasound, etc., and if NSE is positive, focus on abdominal X-ray and CT, etc. If the examination reveals problems, it can be used in early diagnosis and treatment of asymptomatic tumor with good effect. If the tumor marker is positive and no tumor is found in other examinations, it should be re-examined in 3 months or half a year, if it is still increased, other methods should be conducted on the corresponding organs, if it becomes negative result, it can be changed to once a year. For patients whose cancer has been confirmed and treated accordingly, monitoring of tumor markers can be followed up. If the test result is positive, it indicates that the tumor has the tendency to recur, so other tests should be done in time to determine it and intensive treatment should be carried out in time; if the result is negative, the time of further chemotherapy can be extended appropriately according to the doctor’s judgment. 20.Can tumors be prevented? The factors affecting the occurrence of tumor include in vivo factors and in vitro factors. In vivo factors include: genetic factors, gender factors, age factors and immune status of the body. The internal factors cannot be prevented and the current medical level is not yet mature. In vitro factors include: physical factors, chemical factors, biological factors, etc. External factors involve too many, both environmental factors and personal habits. However, factors such as dietary habits and lifestyle among the external factors can be prevented. Therefore, in 1981, the World Health Organization proposed that “about 1/3 of cancers can be prevented, about 1/3 of cancers can be cured through early detection, early diagnosis and early treatment, and another 1/3 can prolong the survival time and improve the quality of life through appropriate treatment.” 21.What are the methods for early diagnosis of tumor? Tumor is a kind of disease that seriously endangers people’s health, so how to control it effectively is the most urgent task, and the principle of “three early” is advocated clinically, namely early detection, early diagnosis and early treatment. Early diagnosis is the key to cure tumor. In addition to detailed medical history and comprehensive physical examination, doctors often need to choose further examination methods. Such as X-ray examination, angiography, computerized X-ray tomography (commonly known as CT examination), magnetic resonance imaging (also known as MRI), ultrasound examination, radionuclide scanning technology, radioimmuno-scintigraphy, endoscopy, pathology examination (including cytology and biopsy tissue examination), biomarker examination, etc. Currently, the latest and most effective method for early diagnosis of cancer is to look for tumor markers, especially protein markers, through blood tests. Experts believe that it is very necessary to increase the preliminary tumor screening program appropriately among the tumor risk groups (high-risk groups include: people over 45 years old, patients with various chronic inflammatory and chronic diseases, people with family history of tumor, residents of tumor-prone areas, etc.) to prevent tumor problems before they occur, in order to improve the early diagnosis rate of tumor.