What Are Cancer Tumor Markers?

A substance produced and released by tumor cells is often present in the form of metabolites such as antigens, enzymes, hormones, etc. in tumor cells or in host body fluids. The tumor can be identified or diagnosed based on its biochemical or immune characteristics. What are tumor markers The biochemical properties of tumor cells and their metabolic abnormalities, so substances that change qualitatively or quantitatively in the body fluids, exclusions and tissues of tumor patients, these are tumor markers. Tumor markers are mainly used clinically for the discovery of primary tumors, the screening of high-risk populations, the differential diagnosis of benign and malignant tumors, the observation and evaluation of tumor development effects to judge the degree of tumor development, and the prediction of tumor recurrence and prognosis, etc. .

Tumor marker

A substance produced and released by tumor cells, often with

Alpha-fetoprotein (AFP)

(1) 80% AFP of primary liver cancer is> 400ng / ml, and nearly 20% of AFP is normal. AFP can be abnormal before June to December in imaging, which provides an important basis for the early diagnosis of liver cancer. It is recommended that patients with liver cirrhosis regularly review AFP.

(2)

In the fight against malignant tumors, doctors, patients, and family members are often most concerned about (1) how to detect the emergence, development, and metastasis of tumors as early as possible? (2) How to know if the treatment is effective as soon as possible? (3) How to improve the treatment effect? These questions involve how to improve the early detection rate of malignant tumors, how to effectively monitor the treatment effect, adjust the treatment plan at any time, and make each patient get more benefits from each treatment. The development of diagnostic equipment and technologies such as X-ray diagnostic machines, CT machines, and MRI machines has made it possible to find tumors with diameters greater than 5 mm, providing strong support for early detection of tumors and evaluation of treatment effects, and to help doctors modify treatment plans. However, there are still some "residues" of tumors that are difficult to be identified because they are too small or located in a special location in the body. These "fish leaking from the net" quietly grow up in the dark, leading to tumor recurrence and metastasis, which is eventually taken away. The lives of many patients. So, is there any other way to help identify these potential threats? The answer is yes, one of the important indicators is the "tumor marker" widely used in clinical diagnosis and treatment. They are a class of substances that can be detected by testing blood, urine or tumor tissues and reflect the tumor conditions in the body. Compared with the imaging morphological examination methods described above, they can be called "invisible appearance" A powerful complement to the diagnosis.

In a broad sense, tumor markers are substances that are present on or secreted from certain tumor cells and excreted into body fluids. They can be broadly divided into tumor cell secretions and tumor cell expressions. The former is a substance produced by tumor cells during the development and development. The more vigorous the tumor grows, the more its amount is. On the contrary, the tumor growth is suppressed and its amount of production is also reduced. These substances are often glycoproteins, which can be detected and monitored by testing body fluids such as blood. Currently, there are lung cancer tumor marker groups (CEA, Cyfra21-1, NSE, etc.), gastrointestinal tumor marker groups (CEA, CA199, CA242, CA724, etc.), CA153 (breast cancer, etc.), CA125 (ovarian cancer, etc.) , AFP (liver cancer, etc.), PSA (prostate cancer, etc.), HCG (velvet cancer, etc.). They are often detectable when the tumor is very small, which helps to detect the lesions early; it may indicate that the effect is not good; if the marker is gradually increased after surgical removal of the tumor for a period of time, it often indicates that tumor cells may have proliferated in the body , Growth, if significantly reduced after treatment, it indicates that the treatment is effective, otherwise, close monitoring is required. Therefore, experienced oncologists often perform imaging tests on patients, assess tumor size while taking blood tests, and dynamically observe corresponding markers to understand whether tumor growth is still active and whether its activity is inhibited after treatment. Their characteristics are that they reflect sensitivity and can often determine the tumor growth status earlier than CT, MRI and other means, reminding doctors if they need to change the treatment; their weakness is lower accuracy and not as reliable as imaging diagnosis; therefore, they often need to be tested together. Individual markers, dynamically observe their changes, and make judgments in conjunction with other clinical features. It is commonly used in clinical practice: (1) early warning of the occurrence and development of tumors; (2) dynamic monitoring to reflect the treatment effect; (3) certain hints on the nature of tumors when it is impossible to obtain tumor specimens and clear pathological diagnosis, and it is experimental Treatment provides a reference.

The second type of "special markers" can also be called "tumor cell expressions", which are often some special structural points on the tumor cell membrane or intracellular structure, such as epithelial growth factor receptor (EGFR), vascular endothelial growth factor receptor (VEGFR), estrogen receptor (ER), progesterone receptor (PR), CD20 receptor and so on. The first feature is that they are mostly on the surface of tumor cells and less on the surface of normal cells. The second feature is that they can be specifically recognized and bound by certain drugs, thus becoming "targets" for tracking and combating these drugs. Once such drugs are combined, they will activate the "death signal" in tumor cells like a key inserted into a keyhole, killing the tumor, and rarely damage normal cells. As the name suggests, such drugs are called "targeted drugs" and their corresponding treatments are also called "targeted treatments". For example: EGFR inhibitors, anti-angiogenesis drugs, estrogen antagonists, CD20 monoclonal antibodies, etc., have been widely used in the treatment of lung cancer, breast cancer, lymphoma and other malignant tumors. Such "expressions" often need to be detected by direct examination of the tumor tissue. Therefore, experienced oncologists often examine tumor specimens after surgical resection or resection to understand whether their expression is high or low. Treatment strategy provides a reference.

In recent years, new tumor markers have been continuously discovered and examination methods have been continuously improved, which has made their sensitivity and accuracy constantly improve. It is believed that in the future, the emerging discipline of "tumor marker science" will achieve longer development and provide a more sufficient basis for early reflection of tumor changes in the body.